Download micromachines-13-00060

micromachines
Review
Ultrawideband Antennas: Growth and Evolution
Om Prakash Kumar 1 , Pramod Kumar 1, * , Tanweer Ali 1, * , Pradeep Kumar 2, *
1
2
3
*
Citation: Kumar, O.P.; Kumar, P.; Ali,
T.; Kumar, P.; Vincent, S.
Ultrawideband Antennas: Growth
and Shweta Vincent 3, *
Department of Electronics and Communication Engineering, Manipal Institute of Technology,
Manipal Academy of Higher Education, Manipal 576104, India; [email protected]
Discipline of Electrical, Electronic and Computer Engineering, University of KwaZulu-Natal,
Durban 4041, South Africa
Department of Mechatronics Engineering, Manipal Institute of Technology, Manipal Academy of
Higher Education, Manipal 576104, India
Correspondence: [email protected] (P.K.); [email protected] (T.A.); [email protected] (P.K.);
[email protected] (S.V.)
Abstract: Narrowband antennas fail to radiate short pulses of nano- or picosecond length over the
broader band of frequencies. Therefore, Ultrawideband (UWB) technology has gained momentum
over the past couple of years as it utilizes a wide range of frequencies, typically between 3.1–10.6 GHz.
UWB antennas have been utilized for various applications such as ground-penetrating radars, disaster management through detection of unexploded mines, medical diagnostics, and commercial
applications ranging from USB dongles to detection of cracks in highways and bridges. In the first
section of the manuscript, UWB technology is detailed with its importance for future wireless communications systems. In the next section various types of UWB antennas and their design methodology
are reviewed, and their important characteristics are highlighted. In section four the concept of a
UWB notch antenna is presented. Here various methods to obtain the notch, such as slots, parasitic
resonators, metamaterials, and filters are discussed in detail. In addition, various types of important
notch antenna design with their technical specifications, advantages, and disadvantages are presented.
Finally, the need of reconfigurable UWB notch antennas is discussed in the next section. Here various
insight to the design of frequency reconfigurable notch antennas is discussed and presented. Overall,
this article aims to showcase the beginnings of UWB technology, the reason for the emergence of
notching in specific frequency bands, and ultimately the need for reconfiguring UWB antennas along
with their usage.
and Evolution. Micromachines 2022,
13, 60. https://doi.org/10.3390/
mi13010060
Keywords: ultrawideband (UWB); ultrawideband (UWB) notch antenna; frequency reconfigurable
ultrawideband (UWB) notch antenna
Academic Editor: Piotr Kurgan
Received: 6 November 2021
Accepted: 17 December 2021
1. Introduction
Published: 30 December 2021
The electromagnetic spectrum has a finite range of frequencies that have been used
for various forms of communication. The ultrawideband (UWB) has expanded this spectrum of frequencies for a broader range of applications by typically using nanosecond or
picosecond pulses, which operate over a wide range of frequencies. Broadband antennas
are incapable of passing such pulses for a short time period, leading to dispersion and
distorted communication. Therefore, UWB technology has gained momentum over the
past couple of years. The Federal Communications Commission (FCC) [1] defines a UWB
spectrum as having a fractional bandwidth of typically greater than 0.2, where fractional
bandwidth is defined by Equation (1).
Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affiliations.
Copyright: © 2021 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
Fractional Bandwidth = 2 ×
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
( fH − fL )
( fH + fL )
(1)
where the upper 10 dB cut-off frequency is denoted by f H and the lower 10 dB cut-off
frequency is denoted by f L .
4.0/).
Micromachines 2022, 13, 60. https://doi.org/10.3390/mi13010060
https://www.mdpi.com/journal/micromachines
Micromachines 2022, 13, 60
2 of 45
An alternate definition of UWB technology requires the waveforms to have an absolute
bandwidth of greater than 500 MHz. The pulses used in UWB technology have a short pulse
width; they occupy a large bandwidth during transmission. UWB technology is typically
used for video streaming, performing movie transfers, camera downloads, printing files on
printers, and MP3 file transfers. However, the range of UWB pulses is limited from a few
meters to a maximum of 50 m. Their speed ranges from typically 100 Kbps used in wireless
sensor networks (WSN) to other higher speed communications typically of 1 Gbps.
The UWB technology has created a boom in the field of communication by proving
its vitality in several applications viz., ground penetrating radar (GPR) for emergency
communication during earthquakes or avalanches, detection of unexploded mines, health
check of civil engineering structures such as highways and buildings, body area networks
(BAN) and detection of water in subsurface soil layers for effective agricultural practices.
This article is arranged as follows. Section 2 describes the inception of applications
that use the UWB technology for communication. Section 3 elaborates on the different
designs of UWB antennas from 2000 to date. Section 4 presents an exhaustive survey of
UWB notched antenna in order to mitigate the electromagnetic interferences (EMI) between
the sub-bands. Since their inception, Section 5 presents the concept of reconfigurable UWB
antennas and showcases the latest state-of-the-art antenna architectures.
2. UWB Antenna Technology
In [2], the authors have described the design of a bistatic synthetic aperture radar
system for communication overboard a satellite. They used two antennae, one for transmission and the other for the reception of data with typical values of gain between 10 dB
to 20 dB. The BISSAT (BIstatic Sar SATellite) antenna proposed was designed to work in
the C-band. In [3], the authors outlined the issues that were faced for the usage of global
positioning systems (GPS) aboard satellites. One of the primary concerns which ultimately
paved the way for the need for UWB communication was the need to provide resilience
to radio interference, i.e., for example, the International Telecommunication Union (ITU)
had already designated the 2025 MHz–2110 MHz for Earth to space communication, and
this frequency range interfered with terrestrial radio communication bands. This issue was
therefore paving the way for UWB communication. In [4] the author described one of the
preliminary usages of UWB communication which was for the detection of targets at sea.
Their proposed technique utilized the characteristic of a large bandwidth of UWB antennas
to remove the sea clutter and improve the target to clutter ratio for effectively detecting
a target. In [5] authors also presented the potential of the usage of UWB technology for
the future to enable ad hoc ubiquitous communication. The authors in [6,7] showcased a
study conducted by Wireless World Research Forum (WWRF) on the need for new wireless
interfaces and issues related to exhaustion of the then spectrum of 3G communication. This
was a leading piece of research for the advent of UWB communications.
The usage of UWB technology for car antennae used for navigation and other forms
of communication was demonstrated by [8]. Both the antennae used for mobile and navigation communication were spiral in structure which operated at 350 MHz and 800 MHz,
respectively. A significant application of the UWB technology was presented in [9] in the
form of ground-penetrating radar (GPR). The authors of the article used a dielectric rod
antenna that operated between the 1 GHz to 6 GHz frequency range, resulting in weak
antenna–ground interaction. This enabled the novel design to be used for GPR applications. On similar lines in [10], the authors designed a Vee dipole antenna with resistive
loads for UWB GPR applications. The wide range of frequency operations ranged from
500 MHz–8 GHz.
In [11] author presents a revolutionary article that proved the ability of UWB communication systems to coexist with Fixed Wireless Access (FWA) indoor systems operating in
the frequency range of 3.5 GHz to 5 GHz. In [12], the authors investigated the effects of
UWB technology on the existing 3G Wi-Fi networks. Their study showed through statistical
Micromachines 2022, 13, 60
3 of 45
analysis that if the UWB technology were not rolled out properly, the Wi-Fi throughput
would be negatively impacted by 20%.
In the article [13], the authors have designed an adaptable ultrawideband wearable
antenna for WBAN applications. The antenna design comprises a textile jeans substrate
with a copper tape for the radiator patch and the ground plane. The proposed antenna
showcases an optimum S11 value and radiation pattern under various bending conditions.
The efficiency of the antenna in terms of return loss has been tested for planar and bending
configurations. The antenna has an operating bandwidth between 2.2 GHz to 17 GHz for
planar configuration. For bending configuration, the antenna radiated between 1 GHz to
1.5 GHz. For both configurations, there is a variation in the antenna twist states based on
the direction of the twist. The radiation pattern is more stable along the Y-axis bending as
opposed to the X-axis bending. In the article [14], the authors have designed a monopole
antenna to diagnose a specific form of skin cancer using radiography. The proposed antenna
has a dimension of (36 × 48 × 6.12) mm with an impedance bandwidth (8.2–13) GHz. The
gain of the antenna is 7.04 dBi. The antenna has performed well in both planar and bending
configurations. For the antenna with AMC, the radiation rate at the rear is lower when
compared to the independent antenna. Further, the same has been noticed when the AMC
antenna is placed on the body. Due to the body’s interference and absorption of energy,
the AMC antenna’s gain when mounted on the body is lower when compared to the AMC
antenna in free space.
In the article [15], the authors have presented the design of a flexible UWB antenna
that showcases a bandwidth of 3.7 GHz to 10.3 GHz. With dimensions of 80 mm × 67 mm,
the proposed antenna has a microstrip patch with two arc-shaped patches. This forms the
entire radiator. Suppression of antenna loading due to the underlying body tissues has
been achieved by using a full ground plane at the bottom of the antenna. The antenna
performance has been studied in free space as well as human body environments. A VSWR
of below 2 has been achieved in both environments. The VSWR remains constant even in
case of bending of the antenna. Peak gain of around 4.53 dBi has been achieved with an
overall efficiency of < 60%. The SAR also conforms to the requirement of lower than 2 W/kg
with values of 0.147, 0.174, and 0.09 at 5 GHz, 7 GHz, and 9 GHz, respectively. However,
slight discrepancies have been noted in simulated and actual measured parameters due
to faulty fabrication. In the article [16], the authors have designed a coplanar waveguide
(CPW) fed flexible UWB antenna which uses Mu-negative metamaterial, which can be used
for wearable applications. They have designed an UWB antenna with 50 mm × 45 mm
dimensions by fabricating it on two materials, namely, flexible FR4 and semi-flexible Rogers
RT/duroid 5880. A bandwidth of 7.2 GHz to 9.2 GHz has been achieved. The overall
gain of the antenna has been improved to 8 dBi by designing a 3 × 3 array. SAR values of
0.3 W/kg and 0.1 W/kg have been achieved for 3 GHz and 10 GHz, respectively.
Authors in [17] have presented the design of a textile antenna for wearable medical
imaging applications. The antenna has been designed in a triangular shape with parallel
slots to enhance radiation in the UWB range of frequencies. Flexible polyester has been used
for constructing the antennas. In [18], the authors presented yet another novel application
of UWB antennas for Wireless Body Area Networks (WBAN). The antennas designed
proved their usage owing to their little thickness of around 0.5 mm. The authors proposed
two physical designs of antennas, viz., a coplanar UWB disc monopole and UWB annular
slot antennas. The antennas operate in the 3.11–10.6 GHz frequency range. In [19] authors
also investigated the usage of UWB technology for WBAN applications. They developed
a novel Swastika slot-ultra-wideband (SS-UWB) patch antenna, which operated in the
frequency range of 3.1–10.6 GHz. Also presented the design of a high-fidelity UWB antenna
for WBAN applications. They implemented a structure with two layers of patches with
a 2 mm thick substrate to enable radio communication over a range of 1 m. In [20], the
authors present yet another flexible UWB antenna used for BAN. It is created by integrating
a conductive tissue-like fabric on polydimethylsiloxane (PDMS) substrate. The antenna
operates at a frequency range of 2.0–2.5 GHz with an efficiency of 70%. Authors in [21]
Micromachines 2022, 13, 60
4 of 45
designed a UWB of 4.68 mm thickness to operate in the frequency range of 4.33 GHz
to13 GHz. The authors have reported that the specific absorption rate (SAR) values of the
antenna reduce by 98.3% when metamaterial is used as the substrate.
Hossain et al. in [22] have designed a bird face monopole ultrawideband antenna. It
showcases an operating bandwidth of 3.10–12.30 GHz. The antenna gain variations are not
uniform. The cross-polarization levels are not discussed. In [23] authors proposed the usage
of antenna arrays aka vector antennas to increase the bandwidth of UWB communication
systems. They designed an antenna array comprising a loop antenna and two orthogonal
bowtie antennas that worked in a 3.6–8.5 GHz frequency range. Moreover, UWB antennas
have also been designed for USB dongle applications [24]. The antenna used is a U-shaped
monopole antenna with a metal plate with a ground plane made of foam. The size of the
antenna is relatively compact for the purpose of the dongle. The antenna design provides
an ultra-wide bandwidth of around 7.6 GHz.
In [25], authors described a yet another revolutionary application of UWB technology:
the designed sensing through the wall systems. This proved to be an integral technology for
military applications in urban terrain. The authors examined the feasibility of UWB signals
through wall imaging in [26]. The authors used UWB noise waveforms as a probing signal
with the principle of heterodyne correlation to image objects behind a wall successfully.
Authors in [27] employed the short-term Fourier transform (STFT) of UWB frequencies
to sense targets across foliage. Similarly, in [28,29], the authors provided an insight on
the usage of support vector machine (SVM) in integration with UWB signals and Singular
value decomposition (SVD) algorithm, respectively, to classify human presence through
the foliage.
Authors in [30,31] investigated the usage of UWB technology for mobile terminals.
The former designed a stubby antenna that resonated in a band of 1.0–6.0 GHz, and the
latter provided a survey of reconfigurable adaptive CMOS circuits using UWB signals for
4G mobile applications. The usage of UWB sensor networks for target localization in the
mining industry was investigated in [32].
As the UWB technology began carving its niche in the wireless domain, [33] presented
a study of its interference with WiMAX systems typically in 2.5–3.5 GHz frequencies.
They concluded that UWB signals with an Effective Isotropic Radiated Power (EIRP) of
83 dBm/MHz or less for a distance of 1 m would not pose any interference to WiMAX signals. Authors in [34] showcased the viability of integrating Bluetooth with UWB technology
over the MAC layer and PHY layer of transmission of signals.
The indoor and location tracking applications in harsh environments using UWB
technology were investigated by [35,36], respectively. In [35], authors stated that for
mission critical scenarios such as rescue requiring drastic measures for mission planning
and execution, it was essential to have systems that could operate in a wide range of
frequencies for which the UWB technology was most suited. In [36] the author extended
to present the feasibility of UWB signals for tracking critical resources in construction
environments. It is used as a support tool for managing construction sites.
In [37–40], the authors proved the feasibility and significance of UWB signals to penetrate through foliage/debris in a critical situation such as an earthquake or a dilapidated
coal mine and detect the presence of life in humans. The fundamental advantage these
researchers tapped in was the excellent penetration capability of UWB signals.
UWB technology was also proposed to be used in the medical field for Microwave
Radiology Imaging (MRI) application in [41]. The authors presented a Slotted Triangular
Flared (STF) patch mounted on a substrate of Teflon. An in-phase reflector increased the
bandwidth of the system, causing it to work in the UWB range of frequencies. In [42], the
authors have revolutionized the medical realm by designing a UWB antenna with slots
for breast cancer detection. The advantage of using UWB for microwave imaging is that it
provides non-ionizing signals with large bandwidth. A mini rectangular patch antenna has
been used for this purpose.
Micromachines 2022, 13, 60
5 of 45
UWB technology has also been proposed for detecting voids in specimens of concrete [43]. This has been achieved by designing a Vivaldi antenna to operate within a
frequency range of 1–30 GHz. The designed antenna has obtained high resolution images.
The authors in [44] showcased the feasibility of UWB communication systems to
become an integral part of 5G wireless systems. A rake receiver for indoor applications has
been designed to mitigate multipath effects and provide throughputs.
UWB technology has also found its application in Near Field imaging applications
used in Synthetic Aperture Radar (SAR) [45]. The authors of this article have designed
an antenna with two dipoles in the orthogonal configuration with elliptical arms and a
modified configuration for feeding. The antenna has been used for the application of
monitoring perforations in an oil well wall. In [46] authors have examined the feasibility
of living in smart homes integrating UWB technology with deep learning for the elderly.
Recognition of activities performed by seniors is done using three UWB radars along with
a deep learning model and a voting system. Table 1 describes the emergence of UWB
technology and its applications in Section 2 above.
Micromachines 2022, 13, 60
6 of 45
Table 1. The emergence of UWB technology and its applications.
Application of UWB
Antenna
Size (mm2 )
Ref. No.
Gain (dBi)
Efficiency (%)
Antenna design
Advantage:
Good performance for
automotive application
Micromachines 2022, 13, x
Mobile multiservice
antenna
400
[8]
5
-
-
Reason for UWB
Performance
Advantage/Disadvantage
The coplanar
waveguide
mode (CPW) and the
coupled slot line mode
(CSL).
Operating Frequency
Range (GHz)
7 of 5
0.6–5.0
Disadvantage:
Not suitable for high
Advantage:
gain
Ground-Penetrating
Radar
600 × 76
[9]
[10]
171.5 × 163.3
171.5 × 163.3
[10]
-
GroundPenetrating
Radar
Ground-Penetrating
Radar
-
6
-
Advantage:
Light weightUse a broad bandwidth
Weak antenna ground
feed to the dielectric
Low radar crossinteraction
circular waveguide’s
1.0–6.0
The(dipole
improved resistively
HE11
section hybridmode).
Disadvantage:
loaded vee dipole (RVD)
Large size
-
Advantage:
by curving the arms and
The improved
Disadvantage:
Light
weight
modifying
resistively
loaded vee the Wu–King
Low radar cross-section
The balun hampers the
dipole (RVD)
resistive profile.
Disadvantage:
0.5–8.0
performance
ofby curving the arms
The balun
hampers the
and modifying the
performance
resistive
resistivelyof loaded Wu–King
vee
resistively loaded vee
profile.
dipole
dipole
(RVD) (RVD)
-
6
-
0.5–8.0
Advantage:
[13]
[13]
[14]
45 × 60
45
× 60
36 × 48
WBAN
applications
WBAN applications
Skin cancer
detection using
radiography
-
-
--
A textile jeans substrate
tape for the
2.2–17
the radiator patch and
Disadvantage:
radiator
patch
and the
the
ground
plane
Large
size
Disadvantage:
ground plane
Large size
Advantage:
Simple structure
A textile jeans substrate
Simple structure
with
copper
with copper
tape
for
Advantage:
Good stability
7
–
Disadvantage:
High SAR
Compact rectangular
AMC antenna
2.2–17
8.2–13
Micromachines 2022, 13, 60
[13]
45 × 60
Advantage:
Simple structure
WBAN
applications
-
Disadvantage:
Large size
Table 1. Cont.
Application of UWB
Antenna
Size (mm2 )
Ref. No.
Gain (dBi)
Efficiency (%)
Antenna design
Advantage/Disadvantage
A textile jeans substrate
with copper tape for the 7 of 45
2.2–17
radiator patch and the
ground plane
Reason for UWB
Performance
Operating Frequency
Range (GHz)
Micromachines 2022, 13, x
8 of 5
Advantage:
Advantage:
Good stability
Good stability
Compact
Compact rectangular
AMC antenna
Disadvantage:
AMC
Advantage:
High
SAR
Disadvantage:
Skin cancer
[14]
[14]
36 × 48
36
× 48
Skin cancer detection
detection
using
radiographyusing
7
7
––
radiography
[15]
80 × 67
80 × 67
[15]
Wearable
applications
Wearable applications
4.53
4.53
ShowsHigh
goodSAR
physical
robustness
Microstrip structure with
2 arc-shaped patches
Disadvantage:
Advantage:
Shows good
Lessphysical
efficiencyMicrostrip structure
< 60%
< 60%
-
robustness
Disadvantage:
Less efficiency
[16]
[16]
50 × 50
45
× 45
Wearable
applications
Wearable applications
8
8
rectangular
8.2–13
antenna
with 2 arc-shaped
patches
3.7–10.3
3.7–10.3
Advantage:
Usage of metamaterial
Advantage:
and array
Usage of metamaterial
configuration
and array configuration gives
Mu-negativeMu-negative
gives increased gain
7.2–9.2
increased gain andmetamaterial
and efficiency
metamaterial
efficiency
Disadvantage:
8585
8.2–13
7.2–9.2
Large size
Disadvantage:
Large size
40 × 45
[17]
[17]
40 × 45
Wearable Microwave
Medical Imaging
Wearable
Microwave
Medical Imaging
2.9
2.9
-
-
-
Advantage:
Easy to fabricate
as it is
Advantage:
Monopole antenna
made of flexible
polyester
Easy
to fabricate aswith
it istriangular and
1.1–4.0
parallel slots on the
made of flexiblelower portion
Monopole
Disadvantage:
of the antenna with
Complex design and
radiating patch
triangular and parallel
possibility ofpolyester
coupling
between the slots
slots on the lower
Disadvantage:
portion of the radiating
Complex design and
patch
possibility of coupling
between the slots
1.1–4.0
Micromachines 2022, 13, x
9 of 5
Micromachines 2022, 13, 60
8 of 45
Micromachines 2022, 13, x
[19]
body
Table 1.Wireless
Cont.
27 × 27
area network
Application of UWB
Antenna
(WBAN)
Size (mm2 )
Ref. No.
Advantage:
Good gain and
efficiency
1.75–5.6
Gain (dBi)
90.6
Efficiency (%)
Antenna design
Wireless body
[19]
[19]
27 × 27
27
× 27
Wireless body
area (WBAN)
network
area network
1.75–5.6
1.75–5.6
90.6
90.6
(WBAN)
[20]
50 × 40
5G wireless
communication
50 × 40
[20]
[20]
5G wireless
communication
50 × 40
3.3
69
3.3
5G wireless
communication
69
3.3
-
69
Wireless body
[21]
[21]
100 ×100
100
× 100
Wireless body area
area
network
network
(WBAN)
6
6
Less thickness
Low
Low SAR
--
[21]
[24]
100 × 100
6 × 11
Wireless USB Dongle
SAR
Disadvantage:
Large size
(WBAN)
Wireless body
area network
(WBAN)
Partial ground plane
9 of 5
with a slot in the patch
3.1–10.6
Operating
Reason for and
UWB notches
at theFrequency
Advantage/Disadvantage
Range (GHz)
Disadvantage: Performance
bottom
The radiation pattern is
not stable.
Advantage:
Good gain and
Advantage:
Partial ground plane
Good gain
and
efficiency
Partial ground plane
efficiency
a slot in the patch
with a slotwith
in the patch
3.1–10.6
3.1–10.6
and notchesand
at thenotches at the
Disadvantage:
bottom
Advantage:
Disadvantage:
The radiation
pattern is
bottom
not stable.antenna with
Flexible
The
radiation pattern is
good
Cutting two slots in the
not efficiency
stable.
2.2–25
ground plane
Disadvantage:
Advantage:
Flexible antenna with
Gain
can be improved.
Cutting two slots in the
good efficiency
2.2–25
ground plane
Advantage:
Disadvantage:
GainFlexible
can be improved.
antenna with
good efficiency
Cutting two slots in the
2.2–25
ground plane
Disadvantage:
Advantage:
Gain
can be
improved.
Less
thickness
Use of rectangular
Advantage:
6
3.2–4.6
Use of rectangular
ground plane
and a plane and a
ground
4.5–13
circular parasitic patch
at the back
of the parasitic patch at
circular
substrate
Disadvantage:
Large size
Advantage:
Less thickness
Low SAR
Advantage:
94
-
the back of the substrate
Use of rectangular
ground plane and a
Good radiation
circular
parasitic patch at
characteristics
Two wide ended
Disadvantage:
the
back
2.9–10.61
radiated arms and of the substrate
Disadvantage:
beveled feed
Ground plane
length
Large size
hampers impedance
bandwidth
4.5–13
4.5–13
6 × 11
6 × 11
[24]
[24]
Wireless USB
Dongle
Dongle
3.2–4.6
3.2–4.6
94
94
Disadvantage:
Disadvantage:
Ground plane length
Ground plane length
hampers impedance
hampers impedance
bandwidth
bandwidth
Micromachines 2022, 13, 60
Table 1. Cont.
Ref. No.
[30]
[30]
5×8
Size (mm52 )× 8
5×8
[30]
Mobile phone
-
Application
of UWB
Mobile
phone Gain (dBi)
Antenna
Mobile phone
-
88
88 (%)
Efficiency
Antenna design
88
-
radiated arms and
radiated arms and
beveled feed
beveled feed
2.9–10.61
2.9–10.61
9 of 45
Advantage:
Advantage:
Good impedance
Good impedance
matching and
Utilization of tapered
matching and
efficiency
0.8–6
Utilization of
tapered
Operating Frequency 0.8–6
for UWBstructure
efficiency Reason
Advantage/Disadvantage
Performance structureRange (GHz)
Advantage:
Disadvantage:
Good impedance
Disadvantage:
Utilization of tapered
matching
and efficiency
Design
complexity
0.8–6
Design complexity structure
Disadvantage:
Design complexity
[40]
[41]
[43]
[45]
Human
Human
respiration and
33.4 × 34.3Humanrespiration
[40]
respiration andand
× 34.3 × 34.3
heart
rate
[40] 33.433.4
heart rate
detection
heart
rate
detection
detection
[41]
[41]
Microwave
Microwave
Microwave
Radiology
Radiology
32 × 32
28 × 28
Imaging
(MRI)
Radiology
applications
Imaging (MRI)
32 × 28
Imaging (MRI)
applications
applications
202 × 96
48.6 × 48.6
Detection of Void
Inside
Concrete Specimens
Near-Field synthetic
aperture radar (SAR)
Imaging
Advantage:
Advantage:
High Gain antenna
Advantage:
High
Gain antenna
14
14 14
High Gain antenna
--
Doppler
Doppler
radar radar technique
10
Disadvantage:
Doppler radar technique
Disadvantage:
technique
Disadvantage:
TheThe
radiation
pattern pattern
radiation
can
be improved.
The
radiation pattern
10
10
can be improved.
can be improved.
6
9.5
6
6
Advantage:
Advantage:
Advantage:
Good
performance for
Good
performance
for
Good
performance
for
applicationsSlottedSlotted
Triangular Flared
Triangular
MRIMRI
applications
7.8–15
MRI applications
Flared Slotted
(STF) patchTriangular Flared
(STF)
patch
Disadvantage:
(STF) patch
Large size
Disadvantage:
Disadvantage:
Large size
Large size
--
-
-
Advantage:
It gives high-quality
image of lost materials.
Use of tapered ground
plane
1–30
circularly polarized
crossed dipole antenna
with elliptical arms
vacated by rotated
elliptical
slot.
1.6–7.2
Disadvantage:
Large size
3
-
-
Advantage:
High impedance
bandwidth and planar
structure
Disadvantage:
Less gain
Note: - indicates not applicable.
7.8–15
7.8–15
Micromachines 2022, 13, 60
10 of 45
3. Progress/Emergence of Design of UWB Antenna
The need for UWB technology was born with the idea of a system encompassing a wide
bandwidth of operation and very low interference with existing technologies such as Wi-Fi,
WiMAX, and GPS. Section 1 described the varied applications developed over the years
using UWB antennas due to their superior bandwidth, gain, and low interference features
as opposed to other wireless technologies. Table 2 lists the important UWB antennas
proposed in the literature with their design specification, advantage and disadvantages.
In [47], the authors have conducted an extensive survey on the promises offered by
the UWB radio technology (UWB-RT), the primary one being to reduce the problem of a
narrow spectrum. The authors have proposed to harness the ability of UWB technology to
work in conjunction with other 3G wireless technologies.
In [48], the author designed a UWB antenna to remove the scattering of waves using
resistive sheets for a slot line bowtie hybrid (SBH) antenna. The authors have employed the
Genetic algorithm (GA) to stabilize the antenna’s beamwidth. A lower radar cross-section
(RCS) is obtained by exploiting the fact that resistive sheets are almost transparent of
EM fields.
In [49], the authors have also been able to obtain a uniform radiation band over the
entire bandwidth with a constant gain of 10 dB by designing a diplexer with two patch
antennas stacked one over the other. In [50], authors have proposed a planar monopole
antenna that is shorted and has a bevel. Their design demonstrates an increase in bandwidth
by combining beveling along with shorting the monopole antenna. A bandwidth of 50 to 1
from 300–15,000 MHz is achieved by [51] by employing the genetic algorithm to generate
the shape of the antenna and the impedance loads connected in series.
The authors in [52] have analyzed the usage of the finite-difference time-domain
(FDTD) method to design horn-fed bowtie antennas (HFB) to work in the UWB frequency
spectrum. A wide bandwidth has been achieved, making these antennas suitable for GPR
applications. In [53], authors have investigated the need for slotting in the conventional
UWB antennas. They utilized the planar inverted cone antenna (PICA), which is used
in the UWB frequency range. The PICA antennas are modified by inserting two holes of
the circular shape to change the flow of current on the metal disk, in turn improving the
bandwidth of the radiation. In [54], authors have also investigated the usage of the FDTD
technique to design two conical plane transmission lines. Their surge impedance has been
calculated for various geometries and various dielectric loads. These antennas radiate in
the UWB range and are suitable for GPR applications. A circular planar monopole with
microstrip line feeding has been designed in [55,56]. Their antenna showcases a return loss
of 10 dB with a stable radiation pattern. The impedance characteristic of an exponentially
tapered UWB TEM horn antenna is improved using a balun of microstrip-type in [57]. The
proposed design showcases a bandwidth three times more than the conventional linearly
tapered TEM horn. In [58], the authors have designed a planar UWB antenna with an
elliptical radiator feed using a microstrip line. Both the radiator and the feed line are
mounted on the same ground plane. The authors of this article have been able to generate
a bandwidth of 110.9% gain from 1.34 dBi to 5.43 dBi within an operating frequency range
from 3–10.6 GHz. UWB operation is achieved using magnetic coupling of two sectorial
loop antennas which are arranged symmetrically in [59]. After optimizing the design, a
VSWR of around 2.2 across 8.5:1 frequency is achieved. In [60], a trident-shaped feed has
achieved UWB characteristics with a bandwidth of about 10 GHz. This feed is integrated
with a square monopole in the planar structure fabricated on a single metal plate.
Micromachines 2022, 13, 60
11 of 45
Table 2. The emergence of design of UWB antenna.
Reference No.
Size (mm2 )
Gain (dBi)
Efficiency
Advantage/Disadvantage
Reason for UWB Performance
Design Methodology
Operating Frequency
Range (GHz)
Bowtie TEM horn
Genetic algorithm
3.1–10.6
introduction of a bevel
Cutting slots in each side
of the
planar element
0.8–10.5
A genetic antenna consisting of a set of
wires connected in series and with
impedance loads
genetic antenna
0.3–15
planar bowtie dipole with the feed point
being raised off the ground
FDTD technique
3.1–10.6
The broadband microstrip line to the slot
line transition causes a large impedance
bandwidth.
Tapered slot
3.1–10.6
Circular disc monopole
fed by microstrip line
Use of the feed gap, the
width of the ground plane,
and the size of the disc.
2.6–10.1
TEM horn antenna with exponential
tapering with a balun of microstrip type
Use of linearly tapered and
exponentially tapered
structure
0.6–15.7
Magnetic coupling of symmetrical
sectoral antennas of loop shape
Two Sectors
2–16
Advantage:
Good impedance matching and compact
in size
[48]
[50]
-
141.4 × 141.4
-
-
-
-
Disadvantage:
Absorber treatment is required in E and
H planes to achieve desired performance
Advantage:
High bandwidth
Stable radiation pattern
Disadvantage:
Large size
[51]
1220 × 1220
-
20–100
Advantage:
Elliptical polarization and near
hemispherical coverage
Disadvantage:
Low efficiency at lower frequencies
[52]
2550 × 2550
-
-
Advantage:
Important design characteristics can be
measured using this FTDT model
Disadvantage:
Complex antenna
[55]
71 × 86
12.5
-
Advantage:
Good group delay
Disadvantage:
Unstable radiation pattern
[56]
50 × 42
8
-
Advantage:
Good frequency characteristics in the
UWB range
Disadvantage:
Poor polarization
[57]
1000 × 3
11
-
Advantage:
Improves bandwidth of TEM horn
antenna
Disadvantage:
High cross-polarization
[59]
200 × 200
8
-
Advantage:
Excellent polarization and good
impedance bandwidth
Disadvantage:
Gain decreases from 6 GHz to 10 GHz
Micromachines 2022, 13, 60
12 of 45
Table 2. Cont.
Reference No.
[60]
Size (mm2 )
150 × 150
Gain (dBi)
7
Efficiency
Advantage/Disadvantage
-
Advantage:
Easily fabricated using the single metal
plate and
Cost-effective
Reason for UWB Performance
Design Methodology
Operating Frequency
Range (GHz)
Trident-Shaped Feeding Strip
Combination of square
planar
monopole antenna with a
trident-shaped feeding
strip
1.4–11.4
Use of conducting wire antenna as a pair
of scissors
scissors antenna consists
of conducting wires
0.2–4
The tapered-slot feed acts transform the
impedance and directs the maximum
radiation from the slot line to the
radiating slot
Tapered slot
3.1–10.6
CPW fed with a U-shaped tuning stub
and elliptical slot
Elliptical slot with U
shaped stub
3.1–10.6
Double exponential tapered slot on LCP
gives end-fire radiation in UWB range of
frequency
Double exponential
tapered slot
3.1–10.6
planar rectangular monopole antenna
with a sleeved transmission line with the
displaced feed point
sleeved transmission linefed rectangular
planar disc monopole
antenna with a small
ground
plane
0.5–9.0
Resonators of varying lengths are added
along the feedline.
Stepped slots
6–22
A tapered loop is formed from the CPW
to CPS to increase the operating
bandwidth
Circular tapered slot
Disadvantage:
Large size
[61]
1000
8
-
Advantage:
It doesn’t need an anechoic chamber for
measurement
Sensitivity to noise is low
Disadvantage:
Efficiency is low
[62]
6.5 × 66.3
6
-
Advantage:
Uniform radiation pattern and less
distortion in the baseband signal
Disadvantage:
The tradeoff between antenna
performance and miniaturization
Advantage:
Omnidirectional radiation pattern
[63]
[64]
40 × 38
136.2 × 66.4
7
12
-
-
Disadvantage:
The time-domain analysis is not
performed
Advantage:
High gain
Disadvantage:
Large size
[65]
126 × 60
-
-
Advantage:
Stable radiation pattern up to 6 GHz
Disadvantage:
Pattern not stable at higher frequencies
[66]
30 × 11.5
2.2
-
Advantage:
Suitable for mm-wave applications
Disadvantage:
Less gain
[67]
120.3 × 24.8
7
80
Advantage:
Large bandwidth and low pulse
distortion
Disadvantage:
Large size and complex structure
3.1–10.6
Micromachines 2022, 13, 60
13 of 45
Table 2. Cont.
Reference No.
[68]
Size (mm2 )
62 × 52
Gain (dBi)
6
Efficiency
Advantage/Disadvantage
Reason for UWB Performance
Design Methodology
Operating Frequency
Range (GHz)
-
Advantage:
Impedance bandwidth of 144.8% and
stable radiation pattern
A circular slot with a new moon-shaped
strip connected to the feed line causes a
wide bandwidth. This is created to
stabilize the radiation pattern at higher
frequencies.
Circular slot with
moon-shaped strip
2.4–11
Beveling the bottom border of planar
monopole antenna
Slot cut in the ground
plane
3.1–12
Slot etching on the ground plane with a
central point feed
leaky slot line
4–40
The curves of the antenna edge by a
binomial function which gives the wider
impedance bandwidth
Use of a binomial function
2.5–10.9
Biconical dipole with metallic reflector
Tapered stripline balun
3–20
Elliptical
monopole antenna
Elliptical
monopole antenna
12–12.6
Suspended (Plate antenna) structure
It consists of four top
plates connected to a
bottom plate using four
vertical strips.
3.1–4.8
Suspended plate antenna with the
shorting wall
together with the L-probe feed
Parasitic L-shaped plate
3–12
Disadvantage:
Large size
[69]
30 × 46
3.8
-
Advantage:
High efficiency and good
omnidirectional radiation pattern
S11
[70]
160 × 108
18
-
Disadvantage:
> −10 dB for 3.1 to 4 GHz
Advantage:
Good gain and directivity.
Negligible cross-polarization
Disadvantage:
Weak phase dispersivity
[71]
50 × 46
1.54
-
Advantage:
Simple structure and stable radiation
pattern
Disadvantage:
Less gain and large size
[72]
251.32
7
-
Advantage:
Constant high gain and good transient
response
Disadvantage:
Complex design
[73]
90 × 90
8.2
-
Advantage:
Minimum ringing and dispersion of
pulse in the time domain
Disadvantage:
Large dimension
[74]
47 × 45
9.9
-
Advantage:
Good gain
Disadvantage:
The radiation pattern is moderate.
[75]
100 × 100
5.2
-
Advantage:
Simple design, cost-effective, and
mechanically robust
Disadvantage:
Large size
Micromachines 2022, 13, 60
14 of 45
Table 2. Cont.
Reference No.
[76]
Size (mm2 )
30 × 8
Gain (dBi)
4
Efficiency
-
Advantage/Disadvantage
Advantage:
Omnidirectional radiation patter with
low cross-polarization
Disadvantage:
High insertion loss below 5 GHz and
limited gain therein
Advantage:
Low VSWR, stable gain and linear phase
[77]
[78]
30 × 20
71 × 71
4.13
4
-
-
Disadvantage:
There is a reduction in radiation
efficiency due to an increase in input
impedance in the mid UWB band.
Advantage:
Simple feeding structure and good
bandwidth
Reason for UWB Performance
Design Methodology
Operating Frequency
Range (GHz)
The planar monopole has strong vertical
currents, which leads to large impedance
bandwidth. A triangular feeding strip is
used.
Rectangular monopole
with an equal-width
ground
plane
2.7–16.2
There are electric and magnetic radiators.
Energy stored in matching stubs is
radiated because of the CPW-slot line
transition.
Two rectangular slots
3.1–10.6
The polygonal slot results in bandwidth
enhancement
Polygonal slot
1.8–5.9
Asymmetrical beveled rectangular patch
with a U slot causes enhancement in
bandwidth
Asymmetrical rectangular
patch with U shaped slot
2.9–12.1
Disadvantage:
Large size
[79]
24.5 × 24.5
5.9
-
Advantage:
Small size with impedance bandwidth of
122%
Disadvantage:
The radiation pattern is quite unstable.
Note: - indicates not applicable.
Micromachines 2022, 13, 60
15 of 45
The Scissors antenna has been designed by [61] for transient UWB applications. It
consists of conducting wires which radiate ultrashort pulses having low dispersion. It
has been proven to have a better radiation characteristic in comparison to conventional
harmonic measurements. A UWB within the frequency range of 0.5–9 GHz has been
designed in [63]. The authors have used a monopole in the shape of a rectangular disc
which is fed with a sleeved transmission line with a small ground plane to achieve this
high bandwidth. A UWB usable for handset applications with a folded metallic element
connected to a printed section has been proposed in [69]. Various paths for current have
been created, thereby increasing the dimensions of the antenna. The antenna has a quasiomnidirectional radiation pattern over the entire UWB frequency range of operation.
The UWB leaky lens antenna has been designed in [70], which utilizes the property of
Cherenkov radiation occurrence in a slot that is printed in the conjunction of infinite homogeneous dielectrics. This results in a directive antenna that has non-dispersive characteristics.
The binomial function has been used to design the edge of the curve of the planar
antenna designed in [71]. Different orders of the binomial function have been used along
with varying widths of the gaps between the antenna and the ground plane. The proposed
antenna showcases an omnidirectional pattern of radiation in the UWB range of frequencies.
In [72], a rod antenna with a metal reflector that operates in the UWB range has been
presented. The antenna is fed with a biconical dipole with a microstrip line balun. This
design showcases a bandwidth of operation from 3–20 GHz. It also exhibits very less
dispersive effects.
A planar UWB elliptical monopole antenna has been presented in [73]. An ellipticity
ratio of 1.1 gives a UWB ratio of 12.4:1 as opposed to 10.2:1 as of a circular monopole
antenna. A suspended plate antenna (SPA) has been designed in [74]. The bottom layer
plate is suspended over the ground and has a feed that is tapered towards it. The upper
layer has four radiation plates, each connected to the bottom plate using vertical metallic
strips. The proposed antenna radiates in the frequency range of 2.8–6 GHz with a stable
gain. A UWB plate antenna with a wall for shorting which is attached to the radiator
has been presented in [75]. The antenna is excited with an L-shaped plate. Due to the
electromagnetic coupling between the feed plate and the radiator, radiation over the UWB
range of frequencies has been achieved. The rest of the antennas tabulated in Table 2
illustrate the various characteristics owing to which a UWB performance has been achieved.
Table 2 tabulates the designs of simple UWB antennas along with their key design features
and radiation characteristics.
As presented in this section, it may be observed that each of the antennas radiates
in the UWB range of frequencies without notching in any range of frequencies. However,
with the improvement in UWB technology, the need for notching in specific frequencies
such as the Wi-Fi, WiMAX was noticed to avoid interference. This led to the emergence of
creation of slots of different shapes and sizes in different positions to generate notches. To
mitigate the effect of EMI between the other devices operating within the UWB frequency
range, Section 4 describes in detail the various literature available for slotted antennas.
4. The Emergence of UWB Notch Antenna
UWB systems present the greatest challenge of overcoming interference with narrowband systems due to their wide bandwidth [80]. Existing technologies such as WiMAX,
which operates in the range of 3.3–3.7 GHz, Wireless LAN, which operates in the range
of 5.15–5.35 GHz, C and X bands of the ITU, which operate in the 7.25–7.75 GHz and
8.025–8.4 GHz, respectively, pose serious possibilities of strong interference to UWB systems. Strong interference due to narrowband systems can result in strong disturbances
similar to background noise. This factor of noise increases the power spectral density of the
signal, thereby reducing the capacity of the UWB system.
The interference between UWB devices and narrowband devices that hampers the
communication systems’ overall performance is mitigated using some novel modifications
on the antenna structures. Several techniques are proposed to design UWB antennas with
Micromachines 2022, 13, 60
16 of 45
frequency stop or frequency notch characteristics. Depending on the application and the
nature and bandwidth of the rejection band, researchers developed novel antennas with an
integrated filtering mechanism that provides the desired response. Several antenna designs
are reported which provide frequency notch response. Some common techniques [81] used
to obtain frequency notches are
•
•
•
•
Modifications on the radiator.
Modifications on the ground plane or signal line.
Integrated filter techniques.
Metamaterial-inspired resonators.
Modifications on the radiator and ground planes in the form of slots, stubs, and slits
are the most common techniques to achieve frequency notches in a UWB-printed antenna.
The literature proposes many configurations using monopole antennas of the planar type,
which have a modified radiator characteristic. These configurations have been used as a
common practice to alter the current path in printed antennas, which affects the antenna’s
input impedance. The aforementioned different geometrical structures with varying sizes
yielded different notching results by changing the current distribution on the radiator of a
UWB antenna.
In [82], a CPW-fed rectangular antenna with a T-shape stub and rectangular slot is
proposed. The proposed design gives a notch between 5–6 GHz. An ultrawideband notch
antenna with a single parasitic strip is proposed in [83]. Notching is achieved by utilizing
an Elliptic slot with three steps, attaching a parasitic strip to the lower end of the antenna,
and varying its length. It shows a notched band between 5.1–5.8 GHz.
A monopole antenna with a C-shape slot on a patch in [84] causes a single notch
in UWB operating band. Slotted radiating surfaces like T-shaped slot [85], octagonal
slot [86], two arc-shaped slots [87], Tapered slot [88], and U-shaped slot [89] are used for
rejecting undesired bands from the UWB spectrum. Different geometrical shapes and
sizes with slots like fractal geometry in the hexagonal monopole with Y-shape slot [90],
Koch Snowflake iterative design with Snowflake slot [91], Fractal Koch structure [92] with
T-shaped stub, and Fractal slot [93], two elliptical patches on a hexagonal radiating patch
with two C-shape slots [94] are utilized to reject the undesired frequency bands. A tripleband UWB notch antenna is proposed in [95] by using decoupling structure, multi-slit, and
multi-slot concepts.
Modifications on the ground plane or signal line were also used to obtain notches
in the operating frequency band of the UWB antennas. A UWB notch antenna using
open-ended slot is proposed in [96]. A staircase shape monopole UWB notch antenna is
proposed in [97]. Wide bandwidth and notching are achieved by utilizing a half-bowtie
radiating element, a U-shaped staircase slot, and a modified ground. An antenna with one
band-notch has been proposed in [98] and [99]. In [99], the antenna has an arc-edged patch
with a partially modified ground plane. The microstrip-fed dipole of semi-elliptical shape
antenna [100], CPW and ACS-fed monopole with DGS [101], CPW-fed L-slot microstrip
antenna [102], offset microstrip-fed UWB antenna with L-shaped slits on the ground [103],
and slots in the shape of arcs in monopoles [104] have been utilized to reject the undesired
frequency bands. A three-band notch antenna has been proposed in [105]. In this design,
two bevels in the patch, two bevels in the ground are used to get wide bandwidth. The
usage of two round slots of half-wavelength along with two slots of C shape in the ground
plane gives a notch at the desired frequency.
Several band rejection techniques like asymmetrical resonator in the feed line, parasitic
strip on the radiator, inverted-L slot on the ground plane [106], tapered edge on the ground
plane and rectangular slots on patch [107], Circular-stub-based multimode-resonator UWB
filter [108], resonant parallel strip (RPS) [109], four stubs and stepped slot in the ground
plane [110], H-slot patch for radiation and a slot of U shape for feeding [111], slot resonators
on Y-shaped monopole radiator [112], parasitic resonator [113], meander line resonator
with open ended stub loading [114], inverted U-shaped and I-shaped slots each of half
guided wavelength on radiator [115], EBG structure [89,116] Notch filter in the patch [117],
Micromachines 2022, 13, 60
17 of 45
parasitic loading and slot techniques [118], DGS and orthogonal polarization [119], inverted
L-shaped stub resonator [120], and a stub with an open end with a meandered resonator
along with defective ground structure [121] are reported in the literature to receive band
notch characteristics.
Recently, metamaterial (MTM)-inspired resonators have been utilized to achieve
notching in UWB operating band. Due to the advancement in consumer electronics, the
antenna on demand must have high channel capacity, gain, bandwidth, and compact
size. Many techniques have been proposed to improve antennas’ performance over the
last decade. One of such techniques is metamaterials. Due to their superior properties
compared to natural materials, Metamaterials have achieved enormous attention from
researchers [122].
MTM inspired antenna is designed using the unit cell structures into the ground plane
or radiator. This unit cell structure acts as a resonant structure in the antenna [123]. A
circular split-ring resonator (C-SRR), Square split-ring resonator (S-SRR), Hexagonal splitring resonator (H-SRR), and Rotational circular split-ring resonator (RC-SRR) are the most
common SRR configurations used for frequency notch applications. Many metamaterialinspired resonators like C-SRR in the signal line [124], Complementary Split Ring Resonator
slot [125], Symmetrical Split Ring Resonator [126], the combination of complementary split
ring resonators (CSRR), split ring resonators (SRR) and DGS [127], SRR [128], open loop
resonators [129], elliptic split ring resonator (ESRR), and a round split ring resonator (RSRR)
along with U-shaped parasitic strips near the signal line [130] are reported in the literature
to receive band notch characteristics.
Based on the above techniques, various metamaterial-based UWB notch antennas are
designed [131–139]. In the paper [131], UWB antenna is designed using double-slotted
ring resonators, circular (C-SRR) and square (S-SRR). It has impedance bandwidth from
3.5–9 GHz and a gain of 5 dBi. It shows multiple band frequencies rejection and stable
radiation patterns. In the paper [132], a UWB monopole notch antenna is designed using
SRR on the ground plane. It has an operating band from 3.1–10.6 GHz It has a notched
band from 5–6 GHz and functions for WLAN. In [133], authors have proposed a dual-band
UWB notch antenna using a CSRR on the patch and the SRR on the ground plane. It is
useful for WiFi 6E and 5G communication. In [134], a UWB antenna is proposed using an
annular SRR slot and a rectangular SRR slot to achieve dual notched band characteristics.
In [135], a UWB notch antenna was designed for 5G, WLAN, and Satellite downlink bands
applications. The authors use EBG structures to notch 5G and WLAN bands and 2 SRR to
notch Satellite downlink bands. A triple-band planer antenna using metamaterials has been
proposed in [136]. This design uses the annular defected ground to get wide bandwidth.
The multi resonant metamaterial cell usage gives a triple band of 2.38–2.48, 3.37–3.79,
and 4.36–6.06 GHz. A single-notch UWB MIMO antenna using a parasitic decoupler has
been proposed in [137]. This design uses a parasitic decoupler to improve the isolation
between antenna elements. The U-shape slot usage in the radiator gives a notched band of
4.2–5.8 GHz. A triple band-notched UWB antenna has been proposed in [138]. This design
uses a SRR in the ground to notch WiMAX (3.3–3.8 GHz) and WLAN (5.15–5.825 GHz).
The U-shape slot usage in the feed line gives a notched band of X-band (7.25–8.395 GHz).
In [139], a UWB notch antenna was designed for rejection of the WLAN band. The authors
use slotted complementary SRRs structures in a circular patch on a partial ground plane to
notch the WLAN band of 5.5 GHz.
Table 3 tabulates the aforementioned sharp band rejection techniques and their key
design features and radiation characteristics to avoid overlapping the UWB with the
interference bands.
Micromachines 2022, 13, 60
18 of 45
Table 3. The emergence of design of UWB notch antenna.
Ref. No.
[82]
[83]
[85]
Micromachines
2022, 13, x
[86]
[87]
[87]
[88]
Size
(mm2 )
35 × 30
20 × 20
30 × 30
29 × 30
26 ×
× 26
26
26
22 × 24
Gain
(dBi)
Antenna DESIGN
-
7
-
3.5
-
7
-
5.4
5
Methodology
-
The rectangular
aperture is designed by
minimizing the
aperture area and
causing impedance
matching.
-
A parasitic strip to the
lower end of the
antenna with varied
lengths causes
notching.
-
4
5
Efficiency
-
-
-
A semielliptical patch
with dielectric
material on
both sides of
the- patch
increases the
effective patch,
thereby
increasing the
bandwidth.
A hexagonal
patch with two
slits is used for
The concentration of
current on the
conductor’s outer edge
and the fork-shaped
strip causes band
rejection in selected
bands
Square ring resonator is
used to achieve
notching.
A semi-elliptical patch
with dielectric material
Two
arc-shaped
on both
sides of the
patch
the
slots increases
which are
effective patch, thereby
connected
increasing
the
bandwidth.
Hexagonal
patch with two
Notching Structure
Advantage/Disadvantage
Notch Frequency
Range (GHz)
Advantage:
Good radiation pattern.
Rectangular slot with T
stub feed
Elliptic slot with three
steps
Disadvantage: Gain
decrease in second
resonant mode due to
cross-polarization
decoupling
Advantage:
Good radiation
characteristics and
impedance matching.
5–6
5.1–5.8
Disadvantage:
Poor cross polarization
Advantage:
Stable radiation pattern.
T shaped slot in a
fork-shaped strip
Octagonal slot with a
rectangular stub for
tuning
Disadvantage:
There is distortion in
the incoming signal in
the frequency band of
interest.
Advantage:
Sharp frequency
notch. 29 of 59
5.1–5.8
5.2–5.9
Disadvantage:
Radiation pattern can
be improved.
Advantage:
Good radiation pattern Advantage:
Good radiation pattern
Twoand
arc-shaped
good slots
gain.
and good gain.
5.1–5.9
which are connected
Disadvantage:
Complex design
Advantage:
Stable radiation pattern
and good gain
Disadvantage:
Complex design
5.1–5.8
5.1–5.9
increases the
effective patch,
thereby
increasing the
bandwidth.
connected
Disadvantage:
Complex design
Micromachines 2022, 13, 60
19 of 45
Table 3. Cont.
Ref.
[88]No.
[88]
[89]
[89]
Size
2
22(mm
× 24
)
22 × 24
38
38 × 38.5
× 38.5
Antenna DESIGN
5.4
-
Gain
(dBi)
-
5.4
5
5
-
UWB antenna
with U-shape
slot- and
asymmetric
rectangular slit
--
Application of
of
Application
fractal
fractal
geometry
in the
geometry
- in the
hexagonal
hexagonal
monopole
monopole
Micromachines 2022,
2022, 13,
13, xx
Micromachines
[90]
[90]
[90]
[91]
[91]
[91]
3333×
××33
33
33
33
33.5
× 28.5
28.5
×
33.5× 28.5
33.5
66
44
6
4
A hexagonal
patch with two
slits is used for
Efficiency
enhanced
bandwidth and
band rejection.
-
--
Use of
of Koch
Koch
Use
Snowflake
Snowflake
iterative design
design
iterative
Hexagonal
patch with two
Methodology
slits for band
rejection
A hexagonal patch with
two slits is used for
enhanced bandwidth
and band rejection.
UWB antenna with
U-shape slot and
U-shape
slot
asymmetric
rectangular
slit
Application of fractal
Y-shape
slot
Y-shape
slot
geometry in
the
hexagonal monopole
Advantage:
Stable radiation pattern
and good gain
Notching Structure
Disadvantage:
Hexagonal patch with
Notch
not
sharp.
two slitsisfor
band
rejection
Advantage:
Stable radiation pattern
and good gain
Advantage:
Advantage:
Stable
radiation pattern
pattern
Stable radiation
Advantage:
and
good
time-domain
and good time-domainStable radiation pattern
and good time-domain
characteristics
5.1–5.8
characteristics
5.1–5.8
Y-shape slot
characteristics
5.1–5.8
4.5–4.6, 7.0–7.4, 8.7–9.3
5.1–5.8
Disadvantage:
Complex structure
Advantage:
Advantage:
Advantage:
Stable
radiation pattern
pattern
Stable radiation
Stable radiation pattern
Snowflake slot
5.1–5.8
5.1–5.8
Disadvantage:
Disadvantage:
Complex
design
Disadvantage:
Complex
design
Complex design
Advantage:
Advantage:
Notch Frequency
Range (GHz)
Disadvantage:
Notch is not sharp.
Advantage:
Stable gain and radiation Advantage:
Stable gain and
characteristics radiation
4.5–4.6,
7.0–
characteristics
U-shape slot
7.4,
8.7–9.3
Disadvantage:
Complex structure
Disadvantage:
30 of
of 59
59
30
Complex structure
Disadvantage:
Disadvantage:
Complex
structure
Complex structure
Use of Koch Snowflake
Snowflake
slot
iterative design
Snowflake
slot
Advantage/Disadvantage
5.1–5.8
5.1–5.8
Micromachines 2022, 13, 60
33.5
× 28.5
[91]
4
Use of Koch
Snowflake
iterative design
-
Advantage:
Stable radiation pattern
Snowflake slot
Size
(mm2 )
40 ×
× 40
40
40
[92]
[92]
Micromachines 2022, 13, x
Gain
(dBi)
Antenna DESIGN
3.5
3.5
Efficiency
Use of fractal
80 with
Koch
CPW feeding
80
Methodology
Use ofFractal
fractal Koch
with CPW feeding
Koch shape slot
Micromachines 2022, 13, x
[93]
6.5
50 × 50
[93]
[93]
5050××50
50
6.5
6.5
5.1–5.8
Disadvantage:
Complex design
Table 3. Cont.
Ref. No.
20 of 45
Notching Structure
Advantage/Disadvantage
Advantage:
Circular polarization
Fractal
Koch shape slot
Disadvantage:
Low gain at 1.5 GHz
Advantage:
Circular polarization
1.5–5.4
Disadvantage:
Low gain at 1.5 GHz
Notch Frequency
Range (GHz)
1.5–5.4
31 of 59
31 of 59
Advantage:
Fractal Koch
Stable
Advantage:radiation pattern
1.7–1.8, 2.2–
Advantage:
68
with
the
stub
of
Fractal
slot
Fractal Koch
Stable radiation pattern
3.1
1.7–1.8,
2.2–
Stable radiation
pattern
Kochslot
with the
68
with the
of Fractal
Fractal
T-shape
68 stub
1.7–1.8, 2.2–3.1
Fractal slotDisadvantage:
stub of T-shape
3.1
Disadvantage:
T-shape
Disadvantage:
Low efficiency
Low efficiency
Low efficiency
[94]
[94] [94]
[95]
20
××20
20 20
×2020
39 × 39
5.98
5.985.98
3.2
-
-
-
Advantage:
Advantage:
Use ofUse
twoof two
Compact size
Advantage:
Compact size
similar
ellipses
similar
ellipses
Use of two similar
Compact size
two
C-shape
3.1–3.8, 4.8– 3.1–3.8, 4.8–
two
C-shape
ellipses on a
3.1–3.8, 4.8–6.1, 7.2–7.8
- a hexagonon a hexagontwo C-shape slots
on
Disadvantage:
hexagon-shaped
slots slots
Disadvantage:
6.1, 7.2–7.8
Disadvantage:
Radiation pattern is 6.1, 7.2–7.8
shaped
shaped radiating patch
RadiationRadiation
pattern is pattern
moderate.
is
radiating
patch patch
radiating
moderate. moderate.
Use of
Use of
decoupling
structure,
decoupling
Multi-slot
multi-slit,
and
structure,
Advantage:
Advantage:
Low mutual coupling
(<
Low
mutual coupling (<
−22
dB)
3.2–3.7, 5.0–
Low ECC −22 dB)
5.9, 7.0–7.9 3.2–3.7, 5.0–
Micromachines 2022, 13, 60
[94]
5.98
20 × 20
-
Table 3. Cont.
Ref. No.
[95]
[95]
Size
(mm2 )
Gain
(dBi)
Antenna DESIGN
3.2
39×
× 39
39
39
3.2
Efficiency
-
Micromachines 2022, 13, x
[96]
[96]
[103]
38 × 38.5
[103]
38
× 38,5
[104]
2.91
19 ×
× 30
19
30
64 × 64
-
2.91
-
70–90
3.6
3.6
Use of
decoupling
structure,
multi-slit, and
multi-slot
concepts
UWB antenna
with T-shaped
70–90
stub and openended slot
75
75
3
Use of two
similar ellipses
on a hexagonshaped
radiating patch
The offset
microstrip-fed
slot antenna
75
Advantage:
Compact size
two C-shape
slots
Methodology
Use of decoupling
Multi-slot
structure,
multi-slit,
and multi-slot concepts
Disadvantage:
Radiation pattern is
moderate.
Notching Structure
21 of 45
3.1–3.8, 4.8–
6.1, 7.2–7.8
Advantage/Disadvantage
Advantage:
Low mutual coupling (< Advantage:
Low mutual coupling (
−22 dB)
<3.2–3.7,
−22 dB ) 5.0–
Multi-slot
Low ECC
Low ECC
5.9, 7.0–7.9
Notch Frequency
Range (GHz)
3.2–3.7, 5.0–5.9, 7.0–7.9
Disadvantage:
Gain can be improved.
32 of 59
Disadvantage:
Gain can be improved.
UWB
antenna with
Open-ended
T-shaped stub and
slot slot
open-ended
The offset
microstrip-fed slot
antenna
Rhombic slot
Use of orthogonal pairs
of differential-fed
elements and the
irregular octagonal
ground plane
Advantage:
Stable radiation pattern Advantage:
Stable radiation pattern
and low ECC
4.3–5.9,
and
low ECC6.5–
Open-ended slot
7.4
Disadvantage:
Low gain
Disadvantage:
Low gain
Advantage:
Sharp notch, low
mutual coupling, and
Advantage:
low envelope
Rhombic slot
correlation coefficient
Sharp notch, low mutual
coupling, and low
envelope correlation
coefficient
5.0–5.9
Disadvantage:
Low efficiency
5.0–5.9
Advantage:
Wide bandwidth and
low cross-polarization
Octagonal-
Disadvantage:
shaped slot
Low efficiency
4.3–5.9, 6.5–7.4
Disadvantage:
Measured efficiency is
lower than simulated
efficiency
5–6.1
[104]
[104]
3
3
64 × 64
64 × 64
Micromachines 2022, 13, 60
75
75
Table 3. Cont.
Size
(mm2 )
Ref. No.
[105]
[105] [105]
31 × 32
31 ×3132× 32
[106] [106]
[106]
× 30
30 ×3030
30 × 30
Gain
(dBi)
Antenna DESIGN
2.5
2.5 2.5
5
5
5
Efficiency
-
-
Micromachines 2022, 13, x
[107]
[107]
[108]
26 26
× ×3030
50 × 40
4.9
5.1
4.9
Use of
orthogonal
orthogonal
pairs of
pairs of
differential-fed
differential-fed
elements and
elements
and
the irregular
the
irregular
octagonal
octagonal
ground
plane
ground plane
90
97
OctagonalOctagonalshaped slot
shaped slot
Methodology
Advantage:and low
Wide bandwidth
Widecross-polarization
bandwidth and low
cross-polarization
Disadvantage:
Disadvantage:
Measured efficiency is
Measured
efficiency
is
lower than
simulated
lower than
simulated
efficiency
efficiency
Notching Structure
5–6.1
5–6.1
Advantage/Disadvantage
22 of 45
Notch Frequency
Range (GHz)
Advantage:
Advantage:
Use of two
Stable
gain and sharp
Use of in
two
Stablenotch
gain and
sharp
bevels
the
Round shaped
band
3.3–3.7, 5.1–
Advantage:
Stable
gain
and
sharp
bevels
in
the
Round
shaped
notch
band
3.3–3.7,
upper edgeUseofof two bevels
slot, in
C-shaped
5.8, and5.1–
7.1–
the
notch band
upper edge of the
Round shaped slot,
3.3–3.7, 5.1–5.8, and
- rectangular
upper
edge of
slot,
C-shaped
5.8,
and
7.1–
the
slots
Disadvantage:
7.7
rectangular ground
7.1–7.7
C-shaped slots
Disadvantage:
the
rectangular
Disadvantage:
7.7
ground
plane plane slots
Unstable
radiation
Unstable radiation
pattern
ground plane
Unstable
radiation
pattern
pattern
Monopole
Monopole
patch
antenna
patch
antenna
consists
of
Advantage:
consists of Monopole patch
semicircular
SimpleAdvantage:
structure and
easy
Advantage:
Simple structure and
antenna consists of
semicircular
Simple
structure
and
easy
radiator semicircular
to
fabricate
3.3–3.8, 5.1–
radiator
easy to fabricate
3.3–3.8, 5.1–5.9, and
truncated with a
- radiatorwith
Inverted-L slotsto fabricate
3.3–3.8,
truncated
Inverted-L
slots
5.9,
and5.1–
8.0–
8.0–8.7
trapezoidal structure
Disadvantage:
and
a
ground
of
Unstable radiation 5.9, and
truncated
with Inverted-L slots
a trapezoidal
Disadvantage:
8.7 8.0–
rectangular shape
pattern
34 of 59
a trapezoidal
Disadvantage:
8.7
structure
and a
Unstable
radiation
structure
and
a
Unstable
radiation
ground of
pattern
ground of
pattern
rectangular
rectangular
shape
Advantage:
shape
Simple structure and
Advantage:
CPW fed
compact sizeSimple structure and
Three
compact size
printed
5.1–5.8 and
CPW fed printed
90
Three rectangular slots
5.1–5.8 and 7.2–8.3
rectangular
Disadvantage:
monopole
antenna
monopole
Disadvantage: Gain is not flat7.2–8.3
slots
antenna
Gain is not flat throughout the
operating band.
throughout the operating
band.
CPW fed UWB
antenna with
EBG structure
Rectangular
slot on the
ground plane
Advantage:
Good gain and better
efficiency
Disadvantage:
Large size
5.1–5.8,
7.1–7.7
Micromachines 2022, 13, 60
[107]
[107]
4.9
4.9
26
26 ×
× 30
30
90
90
CPW
CPW fed
fed
printed
printed
monopole
monopole
antenna
antenna
Three
Three
rectangular
rectangular
slots
slots
Table 3. Cont.
Ref. No.
[108]
[108]
[108]
[109]
[109]
[109]
Size
(mm2 )
50
×
40
50 50
××40
40
104
104
104 × 100
×
× 100
100
Gain
(dBi)
Antenna DESIGN
5.1
5.1
6.5
6.5
5.1
6.5
Efficiency
97
97
[111]
30 30
× ×3030
35 × 30
4.8
6
4.8
--
55
A quasi-Ushape antenna A quasi-U-shape
antenna with four stubs
55 four stubs
with
stepped
slot
and a stepped
ground
plane
and a stepped
ground plane
-
Disadvantage:
Disadvantage:
Gain
Gain is
is not
not flat
flat
throughout
the
operating
throughout the operating
band.
band.
Notching Structure
5.1–5.8
5.1–5.8 and
and
7.2–8.3
7.2–8.3
Advantage/Disadvantage
Rectangular
patch antenna
with H-slot on
Advantage:
Advantage:
Advantage:
Stable
Stable radiation
radiation pattern
pattern
Stable radiation pattern
Resonant parallel strip
3.3–3.6
3.3–3.6
Disadvantage:
Disadvantage:
Large
size
Disadvantage:
35 of 59
Large
Large size
size
5.1–5.8,
7.1–7.7
3.3–3.6
Advantage:
Advantage:
Stable radiation pattern
Stable radiation4.9–5.4,
pattern 5.6–
4.9–5.4, 5.6–5.9
stepped slot
Disadvantage: 5.9
Disadvantage: Less efficiency
Less efficiency
Advantage:
Good gain
H-shaped and
23 of 45
Notch Frequency
Range (GHz)
Advantage:
Advantage:
Good
Good gain
gain and
and better
better
Advantage:
CPW
Rectangular
CPW fed
fed UWB
UWB
Rectangular
Good gain and better
efficiency
5.1–5.8,
efficiency
5.1–5.8,
Rectangular
slot
on
the
fed slot
UWB
antenna
efficiency
antenna
with
the
antenna
withCPW
slot on
on
the
97
with EBG structure
ground plane
7.1–7.7
7.1–7.7
EBG
ground
Disadvantage:
EBG structure
structure
ground plane
plane
Disadvantage:
Disadvantage: Large size
Large
Large size
size
Antipodal
Antipodal
Antipodal
Vivaldi
Vivaldi
antenna
Resonant
Vivaldi
antenna
Resonant
antenna with resonant
with
parallel
strip strip
with resonant
resonant parallel
parallel
strip
parallel
parallel strip
strip
Micromachines 2022, 13, x
[110]
[110]
Methodology
Advantage:
Advantage:
Simple
Simple structure
structure and
and
compact
compact size
size
5.1–5.8,
7.2–7.7,
Micromachines
2022,30
13,×
6030
[110]
[110]
4.8
4.8
30 × 30
55
55
A
A quasi-Uquasi-Ushape
shape antenna
antenna
with
with four
four stubs
stubs
and
and aa stepped
stepped
ground
ground plane
plane
Advantage:
Advantage:
Stable
Stable radiation
radiation pattern
pattern
stepped
stepped slot
slot
Disadvantage:
Disadvantage:
Less
Less efficiency
efficiency
4.9–5.4,
4.9–5.4, 5.6–
5.6–
5.9
5.9
24 of 45
Table 3. Cont.
Ref. No.
[111]
[111]
[111]
[112]
[112]
[112]
Size
(mm2 )
35
×
30
35 35
××
3030
36
×
38
36 36
××
3838
Gain
(dBi)
Antenna DESIGN
66
66
6
6
Efficiency
--
--
Methodology
Rectangular
Rectangular
patch
patch antenna
antenna
Rectangular patch
with
H-slot
H-shaped
and
with H-slot on
onantenna
H-shaped
and
with H-slot on
patch along
with a feed
patch
along
U-shaped
slot
patch along
U-shaped
slot
with a U-slot
with
with aa feed
feed
with
with aa U-slot
U-slot
Y-shaped
Y-shaped
antenna
antenna with
with
slot
of
inverted
slot of inverted
Y-shapedinverted
antenna with
U-shape
UU-shape along
along slot of
inverted
inverted UU-shape
along
with
slot
with
slot
of
Cshaped
and
with slot of Cshaped and aa
of C-shape on radiating
shape
C-shaped
slot
shape on
on patch and
C-shaped
slot
ground plane
radiating
radiating patch
patch
and
and ground
ground
plane
plane
Notching Structure
Advantage/Disadvantage
Advantage:
Advantage:
Good
Good gain
gain
Advantage:
5.1–5.8,
Good gain 5.1–5.8,
H-shaped and
7.2–7.7,
Disadvantage:7.2–7.7,
U-shaped
slot
Disadvantage:
Disadvantage:
Moderate radiation
7.9–8.4
7.9–8.4
Moderate
Moderate radiation
radiation pattern
Notch Frequency
Range (GHz)
5.1–5.8,
7.2–7.7,
7.9–8.4
pattern
pattern
Advantage:
Advantage:
Omnidirectional
Omnidirectional Advantage:
3.4–4.0,
3.4–4.0, 5.1–
5.1–
Omnidirectional
radiation
radiation pattern
patternradiation
pattern
5.9,
inverted U-shaped and
5.9, 6.7–8.0,
6.7–8.0,
3.4–4.0, 5.1–5.9, 6.7–8.0,
8.3–9.1, 9.3–10.6
a C-shaped slot
Disadvantage:
8.3–9.1,
9.3–
8.3–9.1, 9.3–
Disadvantage:
phase response is little
Disadvantage:
10.6
10.6
distorted.
phase
phase response
response is
is little
little
distorted.
distorted.
Micromachines 2022, 13, 60
Micromachines
Micromachines 2022,
2022, 13,
13, xx
Micromachines 2022, 13, x
Ref. No.
[113]
[113]
[113]
[113]
[114]
[114]
[114]
[114]
[115]
[115]
[115]
[115]
25 of 45
36
36 of
of 59
59
36 of 59
Table 3. Cont.
Size
(mm2 )
32
×
24
32 32
××
24
32 ×
2424
20
×
40
40
20 20
××
40
20 × 40
36
24
×
36
24 24
××
36
24 × 36
Gain
(dBi)
Antenna DESIGN
4.4
4.4
4.4
55
5
4.4
5
6.15
6.156.15
6.15
Efficiency
95
95
95
Methodology
Circular
Circular
Circular
monopole
monopole
monopole
antenna
antenna with
with
antenna
with Circular monopole
DGS
with DGS and
DGS and
and antennaRectangular
Rectangular
DGS
and of
Rectangular
resonators
of
95
resonators
slot
inverted-U
and
resonators of
slot
resonators
of
slot
the
iron
shape
on
the
inverted-U
inverted-U and
and
substrate
inverted-U
and
the
the iron
iron shape
shape
thethe
iron
shape
on
on the substrate
substrate
on the substrate
Notching Structure
Advantage/Disadvantage
Advantage:
Advantage:
Advantage:
Compact
Compact size
size
Compact size
Notch Frequency
Range (GHz)
Advantage:
Compact size
5–5.4, 7.8–8.4
5–5.4, 7.8–8.4
Rectangular
slot
Disadvantage:
5–5.4, 7.8–8.4 5–5.4, 7.8–8.4
Disadvantage:
Disadvantage:
Disadvantage:
Distortion
in
the
Distortion
Distortion in
in the
theradiation pattern
Distortionpattern
in the
radiation
radiation pattern
radiation pattern
--
Advantage:
Advantage:
Advantage:
Omnidirectional
Omnidirectional Advantage:
CPW-fed
Omnidirectional
CPW-fed UWB
UWB
radiation
pattern
CPW-fed
UWB
radiation
patternOmnidirectional
antenna
Bandstop
filter
5.7–5.8,
UWB antenna
radiation patternradiation pattern
antenna with
withCPW-fed
Bandstop
filter
5.7–5.8, 8.0–
8.0–
antenna
with with Bandstop
filter Bandstop filter (BSF)
5.7–5.8,
8.0– 5.7–5.8, 8.0–8.4
sharp bandstop
sharp
bandstop
(BSF)
8.4
Disadvantage:
sharp bandstop filter (BSF)
(BSF)
8.4
Disadvantage:
sharp
bandstop
(BSF)
Disadvantage:
Distortions at higher8.4
filter
Disadvantage:
filter (BSF)
(BSF)
frequency
in
E
plane
Distortions
filter (BSF)
Distortions at
at higher
higher
Distortions
atEhigher
frequency
in
frequency in E plane
plane
frequency in E plane
--
Monopole
Monopole
Monopole
ellipzoidal
ellipzoidal
ellipzoidal
antenna
Inverted
Uantenna with
with Monopole
Inverted
Uellipzoidal
antenna
with
Inverted
U-Iantenna
with three
three
slots
of
shape
slot,
three
slots of slotsshape
slot, Iof
inverted
three
slots of U-shapeshape
slot,
Iand
one slot
of
inverted
shape,
and
inverted UUshape,
and
I-shape
slots and
inverted
Ushape,
shape
shape and
and one
one rectangular
rectangular slot
slot
shape
and
one
rectangular
slot
slot
slot of
of I-shape
I-shape
slot of
I-shape
slots
slots
slots
Advantage:
Advantage:
Advantage:
Omnidirectional
Omnidirectional Advantage:
Omnidirectional
Omnidirectional
radiation
pattern
3.2–3.9,
4.3–
radiation
pattern and
and pattern
3.2–3.9,
4.3–
Inverted
U-shape slot,
and
radiation
patternradiation
and
3.2–3.9,
4.3–
3.2–3.9, 4.3–5.0, 5.5–6.6,
I-shape,linear
and phase
linear phase
5.0,
5.5–6.6,
7.9–9.3
linear
phase
5.0,
5.5–6.6,
rectangular
slot phase
linear
5.0,7.9–9.3
5.5–6.6,
Disadvantage:7.9–9.3
7.9–9.3
Complex design
Disadvantage:
Disadvantage:
Disadvantage:
Complex
Complex design
design
Complex design
Micromachines 2022, 13, 60
Micromachines
2022, 13, x
37 of 59 26 of 45
Micromachines 2022, 13, x
37 of 59
Micromachines 2022, 13, x
Table 3. Cont.
Size
(mm2 )
Ref. No.
[116]
[116]
[116]
[116]
[117]
37 of 59
Gain
(dBi)
Antenna DESIGN
64 × 45
5.8
-
64 × 45
5.8
-
5.85.8
-
-
-
64
× 45
×6445
25 × 25
× 25
×2525
[117] [117]
25
[117]
25 × 25
-
-
-
Notch Frequency
Advantage:
Notching Structure
Advantage/Disadvantage
Range (GHz)
Antenna withMethodology
Good
diversity
Advantage:
two
Mushroom
Antenna
with Electromagnetic
parameters
obtained
3.3–3.6, 5–6,
Good
diversity
Advantage:
and
One
Band Gap
two
Mushroom
Electromagnetic
Antenna
with
7.1 –7.9
parameters
obtained
3.3–3.6,
5–6,
Advantage:
Good diversity
Uniplanar
EBG
(EBG)
structure
and
One
Band
two
Mushroom
Electromagnetic
Good diversity
Antenna
with
two Gap
Disadvantage:
7.1 –7.9
parameters
obtainedobtained 3.3–3.6,
5–6,
Electromagnetic
Band
Mushroom
and One
parameters
Uniplanar
(EBG)
structure
3.3–3.6, 5–6, 7.1 –7.9
- Structures
and OneEBG
UniplanarBand
EBG Gap Gap (EBG) structure
Less isolation
Disadvantage:
7.1 –7.9
Structures
Disadvantage:
Structures
Uniplanar
EBG (EBG) structure
Less isolation
Less isolation
Disadvantage:
Structures
CPW-fed
Less isolation
Hexagonal
CPW-fed
Advantage:
Fractal
Hexagonal
CPW-fed
Omnidirectional
Advantage:
Antenna
with
Fractal
Hexagonal
radiation
pattern and
Omnidirectional
Advantage:
Advantage:
design
ofwith
the
Antenna
Fractal
CPW-fed Hexagonal
Hexagonal
and
good
return
loss and
<
Omnidirectional
radiation
pattern
Omnidirectional
grooves
in
the
5.1–5.9
Fractal Antenna with
radiation pattern and
design ofwith
the
Antenna
U-shape
−10
dB
design of the
grooves in slot
Hexagonal
and
Hexagonal
and
good
return
loss
< loss
good and
return
radiation
pattern
groundof
plane
grooves
inthe
theground plane and
5.1–5.95.1–5.9
the
U-shape slot
<−10 dB
design
U-shape
slot
−10
dB
use
of
fractal
geometry
Hexagonal
and
good
return
loss
<
and use
of
ground
plane
grooves
in
the
5.1–5.9
Disadvantage:
and Notch filters.
Disadvantage:
U-shape slot
−10 dB
Complex structure
fractal
and use
of
ground
plane
Complex
structure
Disadvantage:
geometry
and
fractal
and
use of
Complex
structure
Disadvantage:
Notch
filters.
geometry
and
fractal
Complex structure
Notch filters.
geometry
and
Efficiency
-
Notch filters.
[118] [118]
[118]
[118]
32 32 × 16.5
×
3216.5
2.22.2
× 16.5
32
× 16.5
2.2
96
2.2
96
96
Advantage:
A QSCF
omnidirectional
radiation
Advantage:
Advantage:
omnidirectional
antenna
with
pattern
5.1–
A
QSCF
antenna
with
A
QSCF
omnidirectional
radiation
radiation
pattern 3.3–3.8,
96
3.3–3.8, 5.1–5.8, 7.2–8.3
U-shaped
slot U-shaped slot Advantage:
loading slot
and stub
loading
slot
5.8,
7.2–8.3
antenna
with
patternDisadvantage: 3.3–3.8, 5.1–
A QSCF
U-shaped slot omnidirectional radiation
Low gain
and
stub
Disadvantage:
loading
slot
5.8, 7.2–8.3
antenna with
pattern
3.3–3.8,
5.1–
U-shaped
slot
Low
gain
and stub
Disadvantage:
loading
slot
5.8, 7.2–8.3
and stub
Low gain
Disadvantage:
Low gain
Micromachines 2022, 13, 60
Table 3. Cont.
Micromachines 2022,
2022, 13,
13, xx
Micromachines
Ref. No.
[119]
[119][119]
[120]
[120][120]
27 of 45
Size
(mm2 )
38.5
38.5
× 38.5
38.5
×
38.5 × 38.5
20 20
× 14
20
× 14
14
×
38 of
of 59
59
38
Gain
(dBi)
Antenna DESIGN
66
55
Efficiency
[128]
34.6
× 22
34.6 × 22
26 × 26
4
5
Notching Structure
Advantage/Disadvantage
Notch Frequency
Range (GHz)
6 --
inverted-A
inverted-A
Monopole
Monopole
UWB antenna
antenna
UWB
with defected
defected
with
ground
ground
structure
structure
(DGS).
(DGS).
Advantage:
Advantage:
Advantage:
High
isolation and
and low
low
High isolation
inverted-A
High isolation and low
diversity
performance
diversity
performance
Monopole UWB
performance
Rectangular
3.9–4.2, diversity
5.1–
Rectangular
3.9–4.2,
5.1–
antenna with defected
Rectangular slot
slotground structure
5.8
slot
5.8
Disadvantage:
Disadvantage:
Disadvantage:
(DGS).
More number of
More number
number of
of
multipath
More
multipath
multipath
3.9–4.2, 5.1–5.8
580
80
A double
double forkforkA
shaped
shaped
CPW fed
fed
CPW
structure and
and aa
structure
simple 80
simple
symmetrical
symmetrical
inverted LLinverted
shaped
shaped
stub resonator
resonator
stub
Advantage:
Advantage:
Small size
size
Small
Advantage:
Omnidirectional
Omnidirectional
Small size
Omnidirectional
radiation pattern
pattern
A double fork-shaped
radiation
radiation pattern
Inverted
LInverted
CPWLfed structure and
3.4–3.8, 4.5–
4.5–
Inverted L-shaped stub
3.4–3.8,
a simple
shaped
stub symmetrical
shaped
stub
Disadvantage:
resonator.
Disadvantage:
5.5
5.5
inverted L-shapedDisadvantage:
resonator.
At 20 GHz radiation
resonator.
stub resonator
At
20
GHz
radiation
pattern is less
At 20 GHz radiation
bidirectional in
pattern is
is less
less
39the
of 59
pattern
E-plane
bidirectional in
in the
the EEbidirectional
plane
plane
3.4–3.8, 4.5–5.5
Micromachines 2022, 13, x
[121]
[121]
Methodology
4
-
-
UWB
monopole
antenna with
the defective
ground
structure of Pshape
resonators, slot
resonator pair,
a stub of Tshape, and
conductor
plane of two
slits.
UWB Vivaldi
antenna with
two microstrip
feeding lines,
T-shaped slot
on the ground
UWB monopole
antenna with the
defective ground
Resonator,
slot,
structure of P-shape
resonators,
slot
and
slit
resonator pair, a stub of
T-shape, and conductor
plane of two slits.
Advantage:
Sharp notched band and Advantage:
5.1–
Sharp3.3–3.6,
notched band
good time-domain and
good
time-domain
5.3, 5.6–5.9,
Resonator,
slot, and slit
characteristics
characteristics
7.2–7.6, 7.8–
Disadvantage:
8.2, 9.2–9.7
Complex design
Disadvantage:
Complex design
Advantage:
Very low ECC and stable
gain
T-shaped slot
5.3–5.8,
7.8–8.5
3.3–3.6, 5.1–5.3, 5.6–5.9,
7.2–7.6, 7.8–8.2, 9.2–9.7
[121]
34.6
× 22
4
-
Micromachines 2022, 13, 60
Table 3. Cont.
Ref. No.
[128] [128]
Size
(mm2 )
× 26
26 ×2626
Antenna DESIGN
Gain
(dBi)
5
5
-
Micromachines
Micromachines 2022,
2022, 13,
13, x
x
[129]
[129] [129]
[130]
[130] [130]
[131]
[131]
25
× 26
25 ×
×2526
26
× 40
38
38 ×
×3840
40
45
45 ×
× 31
31
6.2
6.26.2
44
5.2
5.2
4
Sharp notched band and
structure of P3.3–3.6, 5.1–
good time-domain
shape
Resonator, slot,
5.3, 5.6–5.9,
characteristics
resonators, slot
and slit
7.2–7.6, 7.8–
resonator pair,
8.2, 9.2–9.7
Disadvantage:
28 of 45
a stub of TComplex design
shape, and
conductor
plane of two
slits.
Notch Frequency
Efficiency
Methodology
Notching Structure
Advantage/Disadvantage
Range (GHz)
UWB Vivaldi
antenna with
Advantage:
two microstrip
Very
low
ECC and
stable
UWB Vivaldi antenna
Advantage:
feeding lines,
with two microstrip
Very
low
and
gain stableECC
feeding lines, T-shaped
gain
T-shaped
slot
5.3–5.8,5.3–5.8,
slot on theT-shaped
ground
slot T-shaped slot
7.8–8.5
Disadvantage:
on the groundplane, and two
7.8–8.5
split-ring resonators
Isolation can be
40
Disadvantage:
40 of
of 59
59
improved
plane, and two (SRR)
Isolation can be
split-ring
improved
resonators
(SRR)
70
70
Advantage:
Advantage:
Antenna
Antenna with
with aa
Compact
good
Advantage:
Compact size
size and
and
good
rectangular
3.3–3.8, 3.7–
rectangular Antenna with
a
Compact size and good3.3–3.8, 3.7–
open-loop
gain
open-loop
gain
rectangular
patch
and
a
3.3–3.8, 3.7– 4.2, 5.1–5.8,
gain
and
a
4.2,
70patch
open-loop
resonator
patch and a
4.2, 5.1–5.8,
5.1–5.8,
5.5–5.9
partialresonator
resonator
Disadvantage:
ground plane
partial
5.5–5.9
partial
5.5–5.9
Less efficiency
Disadvantage:
Disadvantage:
ground
ground plane
plane
Less
efficiency
Less efficiency
--
Antenna
Advantage:
Antenna with
with
Advantage:
elliptic
radiator
elliptic
split
Compact
elliptic radiator
elliptic split
Compact size,
size, wider
wider
Advantage:
and
ring
resonator
bandwidth,
and
more
Antenna with
elliptic
Compact
size, wider 2.9–3.3,
and aa rectangle
rectangle
ring
resonatorelliptic split
bandwidth,
and
more
2.9–3.3, 3.7–
3.7–
ring
radiator and a rectangle
bandwidth, and more
ground
plane
(ESRR)
and
a
notched
bands
3.8,
4.4–4.5,
2.9–3.3,
3.7–3.8, 4.4–4.5,
resonator
(ESRR)
and
a
ground plane
using and a
notched bands
ground
plane
(ESRR)
notched bands
3.8, 4.4–4.5,
5.3–5.5, 7.0–7.3, 7.5–8.0
round split ring
ESRR andround
RSRR with
using
ESRR
split
ring
5.3–5.5,
7.0–
using ESRRU-shaped
round
split ring
5.3–5.5, 7.0–
Disadvantage:
resonator (RSRR)
parasitic
strip resonator
Distortion in radiation 7.3, 7.5–8.0
and
Disadvantage:
and RSRR
RSRR with
with
resonator
Disadvantage:
7.3, 7.5–8.0
pattern
U-shaped
(RSRR)
Distortion
in
radiation
U-shaped
(RSRR)
Distortion in radiation
parasitic
pattern
parasitic strip
strip
pattern
--
Metamaterial
Metamaterial
based
based ring
ring
Double-slotted
Double-slotted
ring
ring resonators
resonators
(SRR),
(SRR), circular
circular
Advantage:
Advantage:
Multiple
Multiple band
band
frequencies
frequencies rejection
rejection and
and
stable
radiation
patterns
stable radiation patterns
4.6–5.4
4.6–5.4
Micromachines 2022, 13, 60
[130]
4
38 × 40
-
Table 3. Cont.
Size
(mm2 )
Ref. No.
[131]
[131]
Gain
(dBi)
Antenna DESIGN
Efficiency
5.25.2
× 31
45 ×4531
Antenna with
elliptic radiator
and a rectangle
ground plane
using ESRR
and RSRR with
U-shaped
parasitic strip
-
Micromachines 2022, 13, x
Micromachines 2022, 13, x
elliptic split
ring resonator
(ESRR) and a
round split ring
resonator
(RSRR)
Methodology
Advantage:
Compact size, wider
bandwidth, and more
notched bands
2.9–3.3, 3.7–
3.8, 4.4–4.5,
5.3–5.5, 7.0–
7.3, 7.5–8.0
Disadvantage:
Distortion in radiation
pattern
Notching Structure
Advantage/Disadvantage
Advantage:
Advantage:
Double-slotted
Multiple band
Multiple band
Metamaterial
ring resonators
frequencies
rejection
Double-slotted
ring
frequenciesand
rejection
based
resonators (SRR),
and stable radiation
- based ringMetamaterial
(SRR), circular
stable and
radiation
patterns
ring resonators
circular (C-SRR),
patterns
resonators
(C-SRR), and square (S-SRR)
Disadvantage:
Complex structure
square (S-SRR)
Disadvantage:
Complex structure
29 of 45
Notch Frequency
Range (GHz)
4.6–5.44.6–5.4
41 of 59
41 of 59
Advantage:
[132]
[132][132]
[133]
[133]
[133]
2416
× 16
24 ×
24 × 16
40×
× 30
30
40
40 × 30
-
-
9.94
-
9.94
9.94
-
58
-
58
Advantage:
Compact size andAdvantage:
simple
Compact
size and simpleCompact size and
SRR on the
MetamaterialSRR on
structure
the
simple structure
Metamaterial
SRR onstructure
the ground
Metamaterial based
based
split
ring
ground
split
ring
resonator
plane
based split ring
5–6
ground
Disadvantage:
resonator
Disadvantage:
Disturbance in the
resonator
Disadvantage:
plane plane
radiation pattern
Disturbance
in the
Disturbance
in the
radiation radiation
pattern pattern
50 × 50
4.71
-
5–6
A
A
Advantage:
Advantage:
complementary
Good isolation, low ECC, Advantage:
complementary
A complementary
Metamaterial
split-ring
isolation,
Good isolation,Good
low
ECC,low
and stable
gain
3.4–3.9,
split-ring
resonator
Metamaterialsplit-ring
based
ECC, and
stable 5.7–
gain
Metamaterial
based58
split ring
resonator
split ring resonator
3.4–3.9,3.4–3.9,
5.7–5.7–6.2
(CSRR) and theand
split stable gain 6.2
Disadvantage:
based
split
ring
resonator
ring resonator (SRR)
resonator
(CSRR) and the
6.2
Low efficiency
Disadvantage:
resonator split(CSRR)
ring and the
Disadvantage:
Low efficiency
split ring
resonator (SRR)
resonator (SRR)
[134]
5–6
Low efficiency
Advantage:
Annular SRR
Better isolation and good
Advantage:
Metamaterial
slot and a
gain
3.3–3.9, 4.7–
based split ring
Annular SRR
Better isolation and good
5.5
Metamaterialrectangular
Micromachines 2022, 13, 60
[133]
9.94
40 × 30
58
Metamaterial
based split ring
resonator
Table 3. Cont.
Ref. No.
[134] [134]
Micromachines 2022, 13, x
Micromachines 2022, 13, x
Size
(mm2 )
× 50
50 ×5050
Antenna DESIGN
Gain
(dBi)
4.71
4.71
Efficiency
30 of 45
Disadvantage:
Low efficiency
Notching Structure
Advantage/Disadvantage
Notch Frequency
Range (GHz)
Advantage:
Advantage:
EBG
and
Compact
sizeand
and
stable
Advantage:
EBG and
Compact size
stable
split-ring
22split-ring
Compact size and 3.4–3.9, 5.1–
Metamaterial
gain
Metamaterial EBG and
3.4–3.9, 5.1–
2 split-ring resonators gain
resonators
stable gain
5.1–5.8, 7.2–7.7
Metamaterial
based
resonators
based
splitring
ring
5.8,3.4–3.9,
7.2–7.7
(SRR)
split ring resonator
based split
5.8,
7.2–7.7
(SRR)
Disadvantage:
(SRR)
resonator
Disadvantage:
Poor isolation
resonator
Disadvantage:
Poor
isolation
Poor isolation
3.86
3.86
3.86
--
[136] [136]
[136]
× 26
29××2926
26
29
3.47
3.47
3.47
--
88
3.4–3.9, 5.7–
6.2
-
20××2026
26
× 26
20
67××67
67
67
Methodology
Advantage:
Good isolation, low ECC,
and stable gain
Advantage:
Annular SRR
Better isolation and
good
Advantage:
Metamaterial
Better isolation and
slot
and
a
gain
3.3–3.9,3.3–3.9,
4.7–4.7–5.5
Metamaterial based
Annular SRR slot and a
good gain
based
split ring
split ring resonator
rectangular SRR
rectangular
5.542 of 59
Disadvantage:
42 of 59
resonator
Large size
SRR
Disadvantage:
Large size
[135] [135]
[135]
[137]
[137]
A
complementary
split-ring
resonator
(CSRR) and the
split ring
resonator (SRR)
79.4
79.4
-
Annular
Annular
defected
defected
ground
ground
Parasitic
Parasitic
decoupler
decoupler
Multi resonant
Advantage:
Advantage:
Multi resonant Multi resonantAdvantage:
Annular defected
Compact
size and
metamaterial
Compact
size
and
simple
ground
metamaterial
cell
metamaterial
Compact size and
simple
simple
structure
cell
cell
U-shapeslot
sloton
on
U-shape
the
patch
the patch
structure
structure
Advantage:
Advantage:
Higher
gain,
Higher gain,
Goodisolation
isolation
Good
Disadvantage:
Disadvantage:
Lessefficiency
efficiency
Less
––
4.2–5.8
4.2–5.8
–
Micromachines 2022, 13, 60
[136]
3.47
29 × 26
-
Annular
defected
ground
Multi resonant
metamaterial
cell
Advantage:
Compact size and simple
structure
31 of 45
–
Table 3. Cont.
Ref. No.
[137] [137]
Size
(mm2 )
Antenna DESIGN
Gain
(dBi)
8
× 67
67 ×6767
8
Efficiency
79.4
Micromachines 2022, 13, x
Micromachines 2022, 13, x
[138]
[138] [138]
[139]
[139]
[139]
24
24 24 × 18.5
×
× 18.5
18.5
44
44
22 × 26
22
22 ×
× 26
26
Note: - indicates not applicable.
4
4
Methodology
Notching Structure
Advantage/Disadvantage
Advantage:
Higher gain,
Advantage:
Higher gain,
Parasitic
U-shape slot on
Good
isolation
U-shape slot on the
Good isolation
79.4
Parasitic decoupler
patch
decoupler
the patch
Disadvantage:
Less efficiency
Disadvantage:
Less efficiency
Notch Frequency
Range (GHz)
4.2–5.84.2–5.8
43 of 59
43 of 59
--
Advantage:
Advantage:
Split
ring
Simple
structure
and
Split
ring
Simple
structure
and
Advantage:
Metamaterial
Metamaterial
Simple structure and 3.3–3.8, 5.1–
resonator
(SRR)
wide
band
resonator
(SRR)
wide
band
3.3–3.8, 5.1–
Split ring resonator
Metamaterial based
based
split
wide band
3.3–3.8, 5.1–5.8, 7.2–8.3
based
split ring
ring
and
U-shape
5.8,
split ring resonator
(SRR) and U-shape slot
and U-shape
5.8, 7.2–8.3
7.2–8.3
resonator
Disadvantage:
resonator
slot
Disadvantage:
High dispersion
slot
Disadvantage:
High
High dispersion
dispersion
--
Advantage:
Advantage:
Metamaterial
Compact
simple
Advantage:
Metamaterial
Compact size,
size,
simple
Compact size, simple
based
Slotted
structure,
wide
and wide
based Metamaterial based
Slotted Slotted complementary
structure, and
andstructure,
wide band
band
band
complementary
complementary
complementary
SRRs structures
complementary
split-ringcomplementary
resonator
Disadvantage:
split-ring
SRRs
structures
Disadvantage:
Gain is not constant in
split-ring
SRRs structures
Disadvantage:
the
operating band.
resonator
Gain
resonator
Gain is
is not
not constant
constant in
in
the
the operating
operating band.
band.
Note: - indicates not applicable.
Note: - indicates not applicable.
4.8–5.7
4.8–5.7
4.8–5.7
Micromachines 2022, 13, 60
32 of 45
5. Frequency Reconfigurable UWB Notch Antenna
The previous two sections have showcased the evolution of UWB antennas and
UWB notch antenna and their design methodology. With the emergence of reconfigurable
circuits, UWB technology also adapted the concept of frequency reconfiguration and several
frequency-reconfigurable UWB notch antennas have been designed.
5.1. Principle of Antenna Reconfiguration
Over the years, antennas can be divided into broad categories, which include wire
antennas, waveguide antennas, log-periodic antennas, microstrip antennas, reflector antennas, and aperture antennas. According to the need of the design, these basic antenna
structures are used to develop new structures to suit the needs. Changing the structure
of an antenna to suit the need of the application is an engineering design problem. Here
is where the concept of reconfiguration has been explored. If antennas are designed to
be reconfigurable, then significant changes in the physical design need not be made to
accommodate changes in the radiation pattern output that may be required [140].
The ability to change an antenna’s fundamental operating characteristics based on
either electrical or mechanical means is termed reconfiguration. Ideally, reconfigurable
antennas can alter their frequency of operation, impedance bandwidths, polarization,
and other radiation parameters to accommodate changes in the output requirements [141].
Despite the huge cost that reconfigurable antennas pose, the concept of reconfigurability has
gained momentum due to its wide range of applications in single element and array antenna
scenarios. Small portable devices which use UWB range of frequencies may have to operate
in harsh or unpredictable environments with weak signal strength in specific ranges of
frequencies. In such cases, the reconfigurable antennas prove their mettle by switching from
one frequency to another based on the conditions of operation. Reconfigurability requires
complex control and feedback circuitry along with complicated fabrication procedures.
Reconfiguration can be made possible in frequency, gain, or polarization. The main focus is
to present frequency reconfigurable UWB notch antennas as they are the most widely used.
5.2. Frequency Reconfigurable Antennas
Frequency reconfigurable antennas have varied operations at different frequencies.
A number of single frequency antennas can be replaced with a single reconfigurable antenna. Frequency reconfigurability is achieved using tuning mechanism, notching, or using
switches [142]. Reconfigurable antennas can be integrated with electronic switches such as a
PIN or Varactor diodes or switching through RF switches. Tunable materials with changing
permittivity and varying height of the substrate can also be used for reconfiguration. PIN
diodes provide the advantage of a low insertion loss, a good switching speed with a small
size, and cheap cost. Lumped components such as PIN diodes, metal-oxide semiconductor
field-effect transistors (MOSFETs), and RF MEMS (radio frequency microelectromechanical
systems) switches can be used for performing switching. MEMS switches outperform PIN
diodes and MOSFETs in terms of providing better isolation and consuming lower power.
Tunable materials such as liquid crystals and ferrites can be used for reconfiguration as
their dielectric constants can be changed with a change in voltage levels. This accounts for
these materials changing their properties into other materials with varied permittivity and
permeability [143].
In [144], electronic switches are placed on the slot of complementary split ring resonators (CSRRs), causing one to activate at a particular instant of time, causing band
notching in a specific range of frequencies. On switching, the notch is created in another
set of frequencies. In a second design, the notching appears when the switch is turned on
and disappears when the switch is turned off. The authors of [145] use PIN diode switches
to reject frequencies belonging to the Bluetooth and wireless LAN bands in UWB operation.
Like [145], in [146], the rejection of WiMAX and WLAN bands is performed using PIN
diodes. In [147], reconfiguration of the UWB antenna is achieved using a band stop filter.
Micromachines 2022, 13, 60
33 of 45
The filters are proposed using SRRs and CSSRs. Notches in four bands are obtained in [148]
by shorting a slot of U-shape. The corresponding reconfiguration is achieved using an
L-shaped slot for a wider band of resonance. In [149], two reconfigurable dielectric UWB
antennas have been presented. Both these antennas achieve reconfigurability through
rotation of the Dielectric Resonator (DR) with a stepper motor connected to it for activation.
The authors of [150] have presented the usage of two PIN diodes in a resonance cell
to achieve reconfiguration of the UWB antenna by regulation of the capacitance using a
varactor diode in the middle of the resonance cell. In [151], the band stop behavior is
reconfigured to a bandpass behavior of the UWB antenna using PIN diodes with the CPW
loaded S-SRRs. The authors of [152] present the design of a reconfigurable UWB antenna
using stepped slots and five PIN diodes for switching in different stages.
The authors of [153] have presented a complex UWB reconfigurable antenna design
that comprises three slots in the ground plane with parasitic strips on the feed resulting
in seven states of operation. Five PIN diodes have been used to perform the switching
between the seven stages of operation. References [154,155] have presented a G-shaped
monopole UWB reconfigurable antenna with a PIN diode for switching and a cup-shaped
UWB reconfigurable antenna with rejection in three bands using stubs and slots with
three PIN diodes for switching, respectively. In [156], the authors have proposed the
usage of hexagonal SRR metamaterial cells and switches for reconfiguration. In [157], the
authors present a design of a band-notched UWB reconfigurable antenna which is achieved
using varactor diodes placed between the split ring slots of the CSSRs used for notching.
Finally, in [158], reconfiguration is achieved in the UWB notched antenna using biasing
circuits of capacitors and inductors and PIN diodes for switching. Table 4 highlights the
key features of the reconfigurable antennas presented above, along with the reasons for
their reconfigurability.
The above section presented some prominent reconfigurable UWB notch antennas until
2020. This section has showcased that with the advent and popularity of reconfiguration,
several antennas have been designed to suit the needs of band notching in the UWB range of
frequencies. Despite the tradeoff of high complexity and preliminary cost of these designs,
frequency reconfigurable antennas are gaining momentum due to the lasting feature of
switching from one frequency to another, thereby reducing the need for multiple antennas
to achieve the same purpose.
Micromachines
Micromachines
2022,
13, xx
Micromachines
2022, 13,2022,
60 13,
46
46 of
of 59
59
34 of 45
Table
The
of
of
UWB
notch
Table
4.design
The emergence
emergence
of design
designreconfigurable
of frequency
frequency reconfigurable
reconfigurable
UWB
notch antenna.
antenna.
Table 4. The emergence
of4.
of frequency
UWB notch
antenna.
Ref.
Size
2
Ref. No. No. Size (mm
( ) )
[144]
[145]
[144]
[145]
30 ×30
30× 30
17 ×17
17× 17
Antenna
Design
Antenna Design
Gain Efficiency
(dBi)
(dBi) Gain (%)
3.12
16
3.12-
1670
[146]
28 ×28
30× 30
Advantage:
Wider band notch
Disadvantage:
Less gain
-
- -
Advantage:
WiderElectronic
band notch
switches
Disadvantage:
Less gain
Advantage:
Advantage:
Compact size and good
Compact size and good
gain
gain
70
PIN
diode
Disadvantage:
Less efficiency
Micromachines 2022, 13, x
[146]
Frequency
Advantage/Disadvantage
Reconfiguration
Efficiency (%)
Advantage/Disadvantage
Mechanism
Disadvantage:
Less efficiency
Advantage:
Advantage:
Each notch band can be
Each notch band can be
controlled separately. controlled separately.
Simple
Simple- design
PINdesign
diodes
Disadvantage:
Disadvantage:
Complex biasing circuit
Complex biasing circuit
Advantage:
More unlicensed users
can operate since it
dynamically rejects a
band.
Design
Frequency
Reconfiguration
Methodology
Mechanism
Operating
Frequency
Design Methodology
(GHz)
Operating
Frequency (GHz)
Complementary
split-ring
Electronic switches
resonators
(CSRRs)
split-ring resonators
3.8–9.5
3.8–9.5
Monopole of Vshape and
electromagnetic
PIN diode
band-gap
structure with Ushaped slot
Monopole of V- shape
and electromagnetic
0.6–30
band-gap structure
with U-shaped slot
0.6–30
A CPW fed UWB
antenna using a
PIN diodes
defected groundplane slit
2.8–10.6
defected ground-plane
Filter antennas
Complementary
(CSRRs)
47 of 59
A CPW fed UWB
antenna using a
slit
2.8–10.6
[146]
28 × 30
-
-
Advantage:
Each notch band can be
controlled separately.
Simple design
PIN diodes
Micromachines 2022, 13, 60
Disadvantage:
Complex biasing circuit
A CPW fed UWB
antenna using a
defected groundplane slit
2.8–10.6
35 of 45
Table 4. Cont.
Ref. No.
[147]
[147]
Size (mm2 )
25 20
× 20
25 ×
Antenna Design
Gain (dBi)
5
5
Efficiency (%)
-
Micromachines 2022, 13, x
Advantage/Disadvantage
Advantage:
More unlicensed users
Advantage:
can operate
since it users
More unlicensed
can operate since it
dynamically
rejects a
dynamically rejects a
band. band.
-
Disadvantage:
The efficiency of the
Disadvantage:
proposed antenna
needs to be further
The efficiency
of the
explored.
Frequency
Reconfiguration
Mechanism
RF switches
RF switches
× 31
30 ×3031
4.5 4.5
-
-
constant group delay
Disadvantage:
50 × 44
4
-
Advantage:
Shows reconfiguration
characteristics for
microwave and WiMax
applications
Disadvantage:
The antenna gain
Operating Frequency
(GHz)
2.1–7.5
2.1–7.5
48 of 59
RF switches
RF switches
Shorting the UShorting the U-shaped
shaped
on
slots onslots
the patch
the patch
Rotation DR
with stepper
motor
Rectangular splitring slot
Disadvantage:
Distortion during pulse
transmission
Distortion during pulse
transmission
[149]
Filter antennas
Filter antennas using
using
CSRRs
and
CSRRs
and SRRs
SRRs
proposed antenna needs
to be further explored.
Advantage:
Simple structure
and
Advantage:
Simple
structure
constant group delay and
[148]
[148]
Design Methodology
2.4–10.8
2.4–10.8
3.2–5.1
Advantage:
Simple structure and
constant group delay
[148]
30 × 31
4.5
Micromachines 2022, 13, 60
-
RF switches
Disadvantage:
Distortion during pulse
transmission
Table 4. Cont.
Ref. No.
[149]
[149]
Size (mm2 )
44
5050×× 44
Antenna Design
Gain (dBi)
44
Efficiency (%)
-
-
Advantage/Disadvantage
Advantage:
Shows reconfiguration
characteristics
for
Advantage:
Shows reconfiguration
microwave
and
WiMax
characteristics for
microwave and WiMax
applications
applications
Disadvantage:
The antenna gain
Disadvantage:
variations are not
uniform.
The antenna
gain
Micromachines 2022, 13, x
Frequency
Reconfiguration
Mechanism
Rotation DR
Rotation DR with
with
stepper
stepper
motor
motor
Shorting the Ushaped slots on
the patch
Design Methodology
Rectangular
splitRectangular split-ring
slot
ring slot
2.4–10.8
36 of 45
Operating Frequency
(GHz)
3.2–5.1
3.2–5.1
49 of 59
variations are not
uniform.
Advantage:
It can mitigate UWB
interference and the
Advantage:
notch
It can mitigate UWB
interference and the
has narrowband
notch
functionality.
has narrowband
functionality.
[150]
[150]
[151]
30 ×
× 30
30
30
35 × 49.4
--
5
-
90
-
Disadvantage:
Disadvantage:
The biasing circuit
utilized to obtain
The biasing
circuit
reconfiguration
affects
the
gain
and
radiation
utilized to obtain
pattern of the antenna
reconfiguration
affects
drastically.
the gain and radiation
pattern of the antenna
drastically.
Advantage:
Simple biasing structure
gives suitable frequency
reconfiguration and
tenability
Disadvantage:
Tuning leads to stray
capacitance.
and
PINPIN
and varactor
diodes
varactor
diodes
Switchable slots
Switchable
slots
3.1–10.6
3.1–10.6
PIN diodes and
the varactor
diode
CPW loaded with
a
switchable/tunable
S-SRR along with
2.1–10.6
Micromachines 2022, 13, 60
37 of 45
Micromachines 2022, 13, x
50 of 59
Table 4. Cont.
Ref. No.
[151]
[152]
Size (mm2 )
35 × 49.4
Antenna Design
Gain (dBi)
-
21 × 9
Efficiency (%)
5
7
80
Advantage/Disadvantage
Advantage:
Simple biasing
structure gives suitable
Advantage:
frequency
Compact size, good
gain,
reconfiguration
and
90
tenability
and radiation efficiency
Frequency
Reconfiguration
Mechanism
CPW loaded with a
PIN diodes and the
switchable/tunable
varactorSlot
diodeAntenna with
S-SRR along with
PIN diode
Disadvantage:
Design Methodology
stepped slots
Operating Frequency
(GHz)
2.1–10.6
2.8–10.7
Tuning leads to stray
Disadvantage:
capacitance.
Complex design Advantage:
[152]
21 × 9
-
7
80
Compact size, good
gain, and radiation
efficiency
PIN diode
Slot Antenna with
stepped slots
2.8–10.7
Disadvantage:
Complex design
Advantage:
It gives seven modesAdvantage:
of
operationIt gives seven modes of
[153]
[153]
40 ×
40
×4040
5
[154]
8 × 27.5
4
5
-
>70
Three slots in the
ground plane with
Three slots in the
operation
parasitic stripsground
on plane with
parasitic strips on
feed
3.1–10.6
Disadvantage:PIN diode PIN diode
Disadvantage:
feed line and
PIN
line
and PIN diodes for
There is distortion in
thein
radiation
There is distortion
the pattern at
diodes for switching
a higher frequency.
radiation pattern at a
switching
higher frequency.
Advantage:
Compact size, stable gain
and reconfigurability
G-shaped
Disadvantage:
PIN diode
monopole with
2.8–12.6
The proposed antenna
PIN diode
does not show stable
radiations at higher
operating frequencies.
3.1–10.6
Advantage:
It gives seven modes of
operation
Micromachines 2022, 13, 60
[153]
40 × 40
5
-
Table 4. Cont.
Ref. No.
Size (mm2 )
Antenna Design
Gain (dBi)
Disadvantage:
There is distortion in the
radiation pattern at a
higher Advantage/Disadvantage
frequency.
Efficiency (%)
Advantage:
Compact size, stable
gain
Advantage:
Compact
size,
stable
and reconfigurability
PIN diode
Frequency
Reconfiguration
Mechanism
gain and
reconfigurability
[154]
[154]
× 27.5
8 ×827.5
Micromachines 2022, 13, x
Micromachines 2022, 13, x
4
4
>70
Disadvantage:
Disadvantage:
The proposed
antenna
The proposed
antenna
does not show stable
radiations
at higher
does not show
stable
operating frequencies.
radiations at higher
operating frequencies.
Advantage:
Advantage:
Good radiation
efficiency
Good radiationAdvantage:
efficiency
>70
Three slots in the
ground plane with
parasitic strips on
feed line and PIN
diodes for
switching
Design Methodology
38 of 45
3.1–10.6
Operating Frequency
(GHz)
diode
PINPIN
diode
G-shaped
G-shaped monopole
monopole
with
with PIN diode
PIN diode
2.8–12.6
2.8–12.6
PIN diode
diode
PINPIN
diode
Monopole antenna
Monopole
Monopoleantenna
antenna
with
T-shaped
slot
with T-shaped slot
with T-shaped slot
3–14
3–14
3–14
PINPIN
diodes
diodes
PIN diodes
Hexagonal
SRR
Hexagonal SRR
Hexagonal
metamaterialSRR
cells
metamaterial
cells
metamaterial cells
2.8–11
2.8–11
2.8–11
Varactor diodes
Varactor diodes
Split-ring slot
Split-ring slot
1.9–10.5
1.9–10.5
51 of 59
51 of 59
Good radiation
[155]
[155]
[155]
[156]
[156]
[156]
22 × 28
22 28
× 28
22 ×
30 ×
4040
30 ×
30 × 40
3
3
6
6
3
6
80–95
80–95
-
efficiency
Disadvantage:
Disadvantage:
Disadvantage:
80–95 The biasing
circuit
The circuit
biasing circuit
The biasing
greatly
affects
theaffects
return
greatly
the
return
loss,
gain, and
greatly
affects
the
return
loss, gain,
and
radiation
radiation pattern.
loss, gain,
and radiation
pattern.
pattern.
Advantage:
Advantage:
Filters
the frequency
Advantage:
Filters of
thenarrowband
frequency
sweep
Filters the frequency
sweep of narrowband
sweep of narrowband
toGHz
8 GHz
-from 5.7 GHz
from 5.7
to 8 GHz
from 5.7 GHz to 8 GHz
Disadvantage:
Complex structure
Disadvantage:
Disadvantage:
Complex structure
Complex structure
[157]
[157]
34.9 × 31.3
34.9 × 31.3
4
4
80–90
80–90
Advantage:
Advantage:
Eliminates
the
Eliminatesof
the
interference
LTE
interference
of
LTE
WiMaz frequency range
WiMaz frequency range
Disadvantage:
Disadvantage:
Design
technique affects
Design
technique
affects
radiation
characteristics
loss, gain, and radiation
pattern.
Advantage:
Filters the frequency
sweep of narrowband
from 5.7 GHz to 8 GHz
Micromachines 2022, 13, 60
[156]
30 × 40
6
-
Table 4. Cont.
Ref. No.
[157]
[157]
Size (mm2 )
Antenna Design
34.934.9
× 31.3
× 31.3
4
80–90
Advantage:
EliminatesAdvantage:
the
interferenceEliminates
of LTE the
interference of LTE
WiMaz frequency
WiMaz frequency
rangerange
80–90
Disadvantage:
Design technique
Disadvantage:
affects radiation
characteristics
Frequency
Reconfiguration
Mechanism
Varactor
diodes
Varactor
diodes
Hexagonal SRR
metamaterial cells
Design Methodology
Split-ring
Split-ringslot
slot
Design technique affects
radiation characteristics
Micromachines 2022, 13, x
[158]
[158]
PIN diodes
Disadvantage:
structure
EfficiencyComplex
(%)
Advantage/Disadvantage
Gain (dBi)
4
39 of 45
21
3333××21
66
70
70
Advantage:
Successfully filters the
Advantage:
WiMaxSuccessfully
and WLAN
filters the
and
WLAN
signalsWiMax
from
the
signals from the
operating
operating
bandband
Disadvantage:
Efficiency can be
Disadvantage:
improved.
Operating Frequency
(GHz)
1.9–10.5
1.9–10.5
52 of 59
Use
of two PIN
Use of two PIN diodes
diodes
Efficiency can be
improved.
Note: - indicates not applicable.
2.8–11
Note: - indicates not applicable.
Two
open-ended
Two open-ended slot
slot
3–10.6
3–10.6
Micromachines 2022, 13, 60
40 of 45
6. Conclusions
This article aims to present the trend of growth of UWB antenna technology from
2001 to 2020. The article describes the great potential of UWB technology in communication and the need to develop it further for varied applications. The first section of this
article presented the UWB technology antennas with their various applications. It has
been clearly observed that UWB technology can cater to several applications, ranging from
ground-penetrating radars for disaster management to medical diagnostics and commercial
applications such as USB dongles and mobile phones. Section 3 of this article presented the
emergence of pure UWB antennas, which radiated in the range of 3.1 to 10.6 GHz. These
antennas do not have notches in any frequency ranges. Due to the interference caused by
the WLAN and WiMAX frequency bands, the concept of notching was introduced in UWB
technology. Several UWB antenna designs have been presented in Section IV, which cause
notching in various frequency ranges. Finally, Section V presented the concept of reconfigurable antennas in UWB technology, their need, and their advantages over conventional
UWB technology. A review of antenna designs and their reason for reconfiguration has
been highlighted in this section. UWB technology and antennas radiating in this range are
here to stay. Therefore, this article aimed at presenting the birth, growth, and most recent
trends in this field.
Author Contributions: All authors contributed equally to this work. All authors have read and
agreed to the published version of the manuscript.
Funding: This research received no external funding.
Institutional Review Board Statement: Not applicable.
Informed Consent Statement: Not applicable.
Data Availability Statement: Not applicable.
Conflicts of Interest: The authors declare no conflict of interest.
References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Federal Communications Commission (FCC). Revision of Part 15 of The Commission’s Rules Regarding Ultra-Wideband
Transmission Systems. In First Report and Order; ET Docket: Washington, DC, USA, 2002; pp. 98–153.
Moccia, A.; Vetrella, S.; Bertoni, R. Mission analysis and design of a bistatic synthetic aperture radar on board a small satellite.
Acta Astronaut. 2000, 47, 819–829. [CrossRef]
Rush, J. Current issues in the use of the global positioning system aboard satellites. Acta Astronaut. 2000, 47, 377–387. [CrossRef]
Wallinga, G.; Rothwell, E.; Chen, K.-M.; Nyquist, D. Enhanced detection of a target in a sea clutter environment using a stepped,
ultra-wideband signal and E-pulse cancellation. IEEE Trans. Antennas Propag. 2001, 49, 1166–1173. [CrossRef]
Remondo, D.; Niemegeers, I.G. Ad hoc networking in future wireless communications. Comput. Commun. 2003, 26, 36–40.
[CrossRef]
Walke, B.H.; Kumar, V. Spectrum issues and new air interfaces. Comput. Commun. 2003, 26, 53–63. [CrossRef]
Tafazolli, R. (Ed.) Technologies for the Wireless Future; Wireless World Research Forum (WWRF); John Wiley & Sons: Hoboken, NJ,
USA, 2006.
Gschwendtner, E.; Wiesbeck, W. Ultra-broadband car antennas for communications and navigation applications. IEEE Trans.
Antennas Propag. 2003, 51, 2020–2027. [CrossRef]
Chen, C.-C.; Rao, K.R.; Lee, R. A new ultrawide-bandwidth dielectric-rod antenna for ground-penetrating radar applications.
IEEE Trans. Antennas Propag. 2003, 51, 371–377. [CrossRef]
Kim, K.; Scott, W. Design of a resistively loaded vee dipole for ultrawide-band ground-penetrating Radar applications. IEEE
Trans. Antennas Propag. 2005, 53, 2525–2532. [CrossRef]
Giuliano, R.; Guidoni, G.; Habib, I.; Mazzenga, F. Coexistence of an ultrawideband spread spectrum system with fixed wireless
access systems. Comput. Netw. 2004, 44, 583–598. [CrossRef]
Lopez, J., Jr.; Raines, R.A.; Temple, M.A.; Baldwin, R.O.; Stephens, J.P., Sr. An investigation on the effects of emerging 4G
transmissions on 3G networks. Omega 2007, 35, 706–714. [CrossRef]
Turkmen, M.; Yalduz, H. Design and Performance Analysis of a Flexible UWB Wearable Textile Antenna on Jeans Substrate. Int. J.
Inf. Electron. Eng. 2018, 8, 15–18. [CrossRef]
Micromachines 2022, 13, 60
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
41 of 45
Mersani, A.; Osman, L.; Ribero, J.-M. Flexible UWB AMC antenna for early stage skin cancer identification. Prog. Electromagn. Res.
M 2019, 80, 71–81. [CrossRef]
Simorangkir, R.B.; Kiourti, A.; Esselle, K.P. UWB Wearable Antenna with a Full Ground Plane Based on PDMS-Embedded
Conductive Fabric. IEEE Antennas Wirel. Propag. Lett. 2018, 17, 493–496. [CrossRef]
Negi, D.; Khanna, R.; Kaur, J. Design and performance analysis of a conformal CPW fed wideband antenna with Mu-Negative
metamaterial for wearable applications. Int. J. Microw. Wirel. Technol. 2019, 11, 806–820. [CrossRef]
Lin, X.; Chen, Y.; Gong, Z.; Seet, B.-C.; Huang, L.; Lu, Y. Ultrawideband Textile Antenna for Wearable Microwave Medical Imaging
Applications. IEEE Trans. Antennas Propag. 2020, 68, 4238–4249. [CrossRef]
Klemm, M.; Troester, G. Textile UWB Antennas for Wireless Body Area Networks. IEEE Trans. Antennas Propag. 2006, 54,
3192–3197. [CrossRef]
Kumar, V.; Gupta, B. On-body measurements of SS-UWB patch antenna for WBAN applications. AEU-Int. J. Electron. Commun.
2016, 70, 668–675. [CrossRef]
Elobaid, H.A.E.; Rahim, S.K.A.; Himdi, M.; Castel, X.; Kasgari, M.A. A Transparent and Flexible Polymer-Fabric Tissue UWB
Antenna for Future Wireless Networks. IEEE Antennas Wirel. Propag. Lett. 2016, 16, 1333–1336. [CrossRef]
Yalduz, H.; Tabaru, T.E.; Kilic, V.T.; Turkmen, M. Design and analysis of low profile and low SAR full-textile UWB wearable
antenna with metamaterial for WBAN applications. AEU-Int. J. Electron. Commun. 2020, 126, 153465. [CrossRef]
Hossain, M.J.; Faruque, M.R.I.; Islam, M.M.; Islam, M.T.; Rahman, M.A. Bird face microstrip printed monopole antenna design for
ultra wide band applications. Frequenz 2016, 70, 473–478. [CrossRef]
Rajagopalan, A.; Gupta, G.; Konanur, A.S.; Hughes, B.; Lazzi, G. Increasing Channel Capacity of an Ultrawideband MIMO System
Using Vector Antennas. IEEE Trans. Antennas Propag. 2007, 55, 2880–2887. [CrossRef]
Su, S.-W.; Chou, J.-H.; Wong, K.-L. Internal Ultrawideband Monopole Antenna for Wireless USB Dongle Applications. IEEE Trans.
Antennas Propag. 2007, 55, 1180–1183. [CrossRef]
Farwell, M.; Ross, J.; Luttrell, R.; Cohen, D.; Chin, W.; Dogaru, T. Sense through the wall system development and design
considerations. J. Frankl. Inst. 2008, 345, 570–591. [CrossRef]
Narayanan, R.M. Through-wall radar imaging using UWB noise waveforms. J. Frankl. Inst. 2008, 345, 659–678. [CrossRef]
Liang, J.; Liang, Q. Sense-Through-Foliage target detection using UWB radar sensor networks. Pattern Recognit. Lett. 2010, 31,
1412–1421. [CrossRef]
He, X.; Jiang, T. Target identification in foliage environment using UWB radar with hybrid wavelet—ICA and SVM method. Phys.
Commun. 2014, 13, 197–204. [CrossRef]
Li, X.; Liang, Q.; Lau, F.C. Sense-through-wall human detection using the UWB radar with sparse SVD. Phys. Commun. 2014, 13,
260–266. [CrossRef]
Zhang, Z.; Langer, J.-C.; Li, K.; Iskander, M. Design of Ultrawideband Mobile Phone Stubby Antenna (824 MHz-6 GHz). IEEE
Trans. Antennas Propag. 2008, 56, 2107–2111. [CrossRef]
José, M.; Castro-Lopez, R.; Morgado, A.; Becerra-Alvarez, E.C.; del Rio, R.; Fernandez, F.V.; Perez-Verdu, B. Adaptive CMOS
analog circuits for 4G mobile terminals—Review and state-of-the-art survey. Microelectron. J. 2009, 40, 156–176.
Chehri, A.; Fortier, P.; Tardif, P.M. UWB-based sensor networks for localization in mining environments. Ad Hoc Netw. 2009, 7,
987–1000. [CrossRef]
Ahmed, B.T.; Campos, J.L.M.; Ruiz-Cruz, J.A. Impact of Ultra Wide Band emission on WiMAX systems at 2.5 and 3.5 GHz.
Comput. Netw. 2010, 54, 1573–1583. [CrossRef]
Van Der Linde, E.; Hancke, G. An investigation of Bluetooth mergence with Ultra Wideband. Ad Hoc Netw. 2011, 9, 852–863.
[CrossRef]
Fuchs, C.; Aschenbruck, N.; Martini, P.; Wieneke, M. Indoor tracking for mission critical scenarios: A survey. Pervasive Mob.
Comput. 2011, 7, 1–15. [CrossRef]
Cheng, T.; Venugopal, M.; Teizer, J.; Vela, P.A. Performance evaluation of ultra wideband technology for construction resource
location tracking in harsh environments. Autom. Constr. 2011, 20, 1173–1184. [CrossRef]
Chunming, W.; Guoliang, D. The Study of UWB Radar Life-Detection for Searching Human Subjects. Energy Procedia 2012, 17,
1028–1033. [CrossRef]
Sun, J.; Li, M. Life detection and location methods using UWB impulse radar in a coal mine. Min. Sci. Technol. 2011, 21, 687–691.
[CrossRef]
Liu, L.; Liu, Z.; Xie, H.; Barrowes, B.; Bagtzoglou, A.C. Numerical simulation of UWB impulse radar vital sign detection at an
earthquake disaster site. Ad Hoc Netw. 2014, 13, 34–41. [CrossRef]
Rabbani, M.S.; Ghafouri-Shiraz, H. Accurate remote vital sign monitoring with 10 GHz ultra-wide patch antenna array. AEU-Int.
J. Electron. Commun. 2017, 77, 36–42. [CrossRef]
Imran, A.I.; Elwi, T.A. A cylindrical wideband slotted patch antenna loaded with Frequency Selective Surface for MRI applications.
Eng. Sci. Technol. Int. J. 2017, 20, 990–996. [CrossRef]
Srikanth, B.S.; Gurung, S.B.; Manu, S.; Gowthami, G.N.; Ali, T.; Pathan, S. A slotted UWB monopole antenna with truncated
ground plane for breast cancer detection. Alex. Eng. J. 2020, 59, 3767–3780. [CrossRef]
Moosazadeh, M.; Kharkovsky, S.; Case, J.T.; Samali, B. Miniaturized UWB Antipodal Vivaldi Antenna and Its Application for
Detection of Void Inside Concrete Specimens. IEEE Antennas Wirel. Propag. Lett. 2016, 16, 1317–1320. [CrossRef]
Micromachines 2022, 13, 60
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
42 of 45
Ghendir, S.; Sbaa, S.; Al-Sherbaz, A.; Ajgou, R.; Chemsa, A. Towards 5G wireless systems: A modified Rake receiver for UWB
indoor multipath channels. Phys. Commun. 2019, 35, 100715. [CrossRef]
Akbarpour, A.; Chamaani, S. Ultrawideband Circularly Polarized Antenna for Near-Field SAR Imaging Applications. IEEE Trans.
Antennas Propag. 2020, 68, 4218–4228. [CrossRef]
Maitre, J.; Bouchard, K.; Bertuglia, C.; Gaboury, S. Recognizing activities of daily living from UWB radars and deep learning.
Expert Syst. Appl. 2021, 164, 113994. [CrossRef]
Hirt, W. Ultra-wideband radio technology: Overview and future research. Comput. Commun. 2003, 26, 46–52. [CrossRef]
Chung, L.; Chang, T.; Burnside, W. An ultrawide-bandwidth tapered resistive TEM horn antenna. IEEE Trans. Antennas Propag.
2000, 48, 1848–1857. [CrossRef]
Ghorbani, K.; Waterhouse, R. Ultrabroadband printed (ubp) antenna. IEEE Trans. Antennas Propag. 2002, 50, 1697–1705. [CrossRef]
Ammann, M.; Chen, Z.N. A wide-band shorted planar monopole with bevel. IEEE Trans. Antennas Propag. 2003, 51, 901–903.
[CrossRef]
Altshuler, E.; Linden, D. An Ultrawide-Band Impedance-Loaded Genetic Antenna. IEEE Trans. Antennas Propag. 2004, 52,
3147–3150. [CrossRef]
Lee, K.-H.; Chen, C.-C.; Teixeira, F.; Lee, R. Modeling and Investigation of a Geometrically Complex UWB GPR Antenna Using
FDTD. IEEE Trans. Antennas Propag. 2004, 52, 1983–1991. [CrossRef]
Suh, S.-Y.; Stutzman, W.; Davis, W. A New Ultrawideband Printed Monopole Antenna: The Planar Inverted Cone Antenna
(PICA). IEEE Trans. Antennas Propag. 2004, 52, 1361–1365. [CrossRef]
Venkatarayalu, N.; Chen, C.-C.; Teixeira, F.; Lee, R. Numerical Modeling of Ultrawide-Band Dielectric Horn Antennas Using
FDTD. IEEE Trans. Antennas Propag. 2004, 52, 1318–1323. [CrossRef]
Ma, T.-G.; Jeng, S.-K. A printed dipole antenna with tapered slot feed for ultrawide-band applications. IEEE Trans. Antennas
Propag. 2005, 53, 3833–3836. [CrossRef]
Liang, J.; Chiau, C.C.; Chen, X.; Parini, C.G. Study of a printed circular disc monopole antenna for UWB systems. IEEE Trans.
Antennas Propag. 2005, 53, 3500–3504. [CrossRef]
Chung, K.; Pyun, S.; Choi, J. Design of an ultrawide-band TEM horn antenna with a microstrip-type balun. IEEE Trans. Antennas
Propag. 2005, 53, 3410–3413. [CrossRef]
Ying, C.; Zhang, Y. A planar antenna in LTCC for single-package ultrawide-band radio. IEEE Trans. Antennas Propag. 2005, 53,
3089–3093. [CrossRef]
Behdad, N.; Sarabandi, K. A compact antenna for ultrawide-band applications. IEEE Trans. Antennas Propag. 2005, 53, 2185–2192.
[CrossRef]
Wong, K.-L.; Wu, C.-H.; Su, S.-W. Ultrawide-band square planar metal-plate monopole antenna with a trident-shaped feeding
strip. IEEE Trans. Antennas Propag. 2005, 53, 1262–1269. [CrossRef]
Andrieu, J.; Nouvet, S.; Bertrand, V.; Beillard, B.; Jecko, B. Transient characterization of a novel ultrawide-band antenna: The
scissors antenna. IEEE Trans. Antennas Propag. 2005, 53, 1254–1261. [CrossRef]
Ma, T.-G.; Jeng, S.-K. Planar miniature tapered-slot-fed annular slot antennas for ultrawide-band radios. IEEE Trans. Antennas
Propag. 2005, 53, 1194–1202. [CrossRef]
Li, P.; Liang, J.; Chen, X. Study of Printed Elliptical/Circular Slot Antennas for Ultrawideband Applications. IEEE Trans. Antennas
Propag. 2006, 54, 1670–1675. [CrossRef]
Thomas, K.; Lenin, N.; Sivaramakrishnan, R. Ultrawideband Planar Disc Monopole. IEEE Trans. Antennas Propag. 2006, 54,
1339–1341. [CrossRef]
Nikolaou, S.; Ponchak, G.; Papapolymerou, J.; Tentzeris, M. Conformal Double Exponentially Tapered Slot Antenna (DETSA) on
LCP for UWB Applications. IEEE Trans. Antennas Propag. 2006, 54, 1663–1669. [CrossRef]
Rambabu, K.; Thiart, H.A.; Bornemann, J.; Yu, S.Y. Ultrawideband Printed-Circuit Antenna. IEEE Trans. Antennas Propag. 2006, 54,
3908–3911. [CrossRef]
Mao, S.-G.; Chen, S.-L. Frequency- and Time-Domain Characterizations of Ultrawideband Tapered Loop Antennas. IEEE Trans.
Antennas Propag. 2007, 55, 3698–3701. [CrossRef]
Qu, S.-W.; Li, J.-L.; Chen, J.-X.; Xue, Q. Ultrawideband Strip-Loaded Circular Slot Antenna with Improved Radiation Patterns.
IEEE Trans. Antennas Propag. 2007, 55, 3348–3353. [CrossRef]
Ruvio, G.; Ammann, M. A Novel Wideband Semi-Planar Miniaturized Antenna. IEEE Trans. Antennas Propag. 2007, 55, 2679–2685.
[CrossRef]
Bruni, S.; Neto, A.; Marliani, F. The ultrawideband leaky lens antenna. IEEE Trans. Antennas Propag. 2007, 55, 2642–2653.
[CrossRef]
Ling, C.-W.; Lo, W.-H.; Yan, R.-H.; Chung, S.-J. Planar Binomial Curved Monopole Antennas for Ultrawideband Communication.
IEEE Trans. Antennas Propag. 2007, 55, 2622–2624. [CrossRef]
Blech, M.D.; Eibert, T.F. A Dipole Excited Ultrawideband Dielectric Rod Antenna with Reflector. IEEE Trans. Antennas Propag.
2007, 55, 1948–1954. [CrossRef]
Ray, K.P.; Ranga, Y. Ultrawideband Printed Elliptical Monopole Antennas. IEEE Trans. Antennas Propag. 2007, 55, 1189–1192.
[CrossRef]
Micromachines 2022, 13, 60
74.
43 of 45
Ni Low, X.; Chen, Z.N.; Toh, W.K. Ultrawideband Suspended Plate Antenna with Enhanced Impedance and Radiation Performance. IEEE Trans. Antennas Propag. 2008, 56, 2490–2495. [CrossRef]
75. See, T.S.P.; Chen, Z.N. An Electromagnetically Coupled UWB Plate Antenna. IEEE Trans. Antennas Propag. 2008, 56, 1476–1479.
[CrossRef]
76. Wu, Q.; Jin, R.; Geng, J.; Ding, M. Printed Omni-Directional UWB Monopole Antenna with Very Compact Size. IEEE Trans.
Antennas Propag. 2008, 56, 896–899. [CrossRef]
77. Kwon, D.-H.; Balzovsky, E.V.; Buyanov, Y.I.; Kim, Y.; Koshelev, V.I. Small Printed Combined Electric-Magnetic Type Ultrawideband
Antenna with Directive Radiation Characteristics. IEEE Trans. Antennas Propag. 2008, 56, 237–241. [CrossRef]
78. Eskandari, H.; Azarmanesh, M.N. Bandwidth enhancement of a printed wide-slot antenna with small slots. AEU-Int. J. Electron.
Commun. 2009, 63, 896–900. [CrossRef]
79. Liu, W.; Yin, Y.; Xu, W.; Zuo, S. Compact Open-Slot Antenna with Bandwidth Enhancement. IEEE Antennas Wirel. Propag. Lett.
2011, 10, 850–853. [CrossRef]
80. Sowmya, G.A.; Kamath, A.; Keshava, A.; Kumar, O.P.; Vincent, S.; Ali, T. A circular monopole patch antenna loaded with inverted
L-shaped stub for GPS application. Bull. Electr. Eng. Inform. 2020, 9, 1950–1957. [CrossRef]
81. Saha, C.; Siddiqui, J.Y.; Antar, Y.M. Multifunctional Ultrawideband Antennas: Trends, Techniques and Applications; CRC Press: Boca
Raton, FL, USA, 2019.
82. Lin, Y.-C.; Hung, K.-J. Compact Ultrawideband Rectangular Aperture Antenna and Band-Notched Designs. IEEE Trans. Antennas
Propag. 2006, 54, 3075–3081. [CrossRef]
83. Kim, K.-H.; Park, S.-O. Analysis of the Small Band-Rejected Antenna with the Parasitic Strip for UWB. IEEE Trans. Antennas
Propag. 2006, 54, 1688–1692. [CrossRef]
84. Qiu, J.; Du, Z.; Lu, J.; Gong, K. A Planar Monopole Antenna Design with Band-Notched Characteristic. IEEE Trans. Antennas
Propag. 2006, 54, 288–292. [CrossRef]
85. Ma, T.-G.; Wu, S.-J. Ultrawideband Band-Notched Folded Strip Monopole Antenna. IEEE Trans. Antennas Propag. 2007, 55,
2473–2479. [CrossRef]
86. Lui, W.-J.; Cheng, C.-H.; Zhu, H.-B. Improved Frequency Notched Ultrawideband Slot Antenna Using Square Ring Resonator.
IEEE Trans. Antennas Propag. 2007, 55, 2445–2450. [CrossRef]
87. Eshtiaghi, R.; Zaker, R.; Nouronia, J.; Ghobadi, C. UWB semi-elliptical printed monopole antenna with subband rejection filter.
AEU-Int. J. Electron. Commun. 2010, 64, 133–141. [CrossRef]
88. Azim, R.; Islam, M.T.; Misran, N. Compact Tapered-Shape Slot Antenna for UWB Applications. IEEE Antennas Wirel. Propag. Lett.
2011, 10, 1190–1193. [CrossRef]
89. Agarwal, M.; Dhanoa, J.K.; Khandelwal, M.K. Ultrawide band two-port MIMO diversity antenna with triple notch bands, stable
gain and suppressed mutual coupling. AEU-Int. J. Electron. Commun. 2020, 120, 153225. [CrossRef]
90. Ghatak, R.; Karmakar, A.; Poddar, D. Hexagonal boundary Sierpinski carpet fractal shaped compact ultrawideband antenna with
band rejection functionality. AEU-Int. J. Electron. Commun. 2013, 67, 250–255. [CrossRef]
91. Roy, B.; Bhattacharya, A.; Chowdhury, S.; Bhattacharjee, A. Wideband Snowflake slot antenna using Koch iteration technique for
wireless and C-band applications. AEU-Int. J. Electron. Commun. 2016, 70, 1467–1472. [CrossRef]
92. Rajabloo, H.; Kooshki, V.A.; Oraizi, H. Compact microstrip fractal Koch slot antenna with ELC coupling load for triple band
application. AEU-Int. J. Electron. Commun. 2017, 73, 144–149. [CrossRef]
93. Zarrabi, F.B.; Mansouri, Z.; Gandji, N.P.; Kuhestani, H. Triple-notch UWB monopole antenna with fractal Koch and T-shaped stub.
AEU-Int. J. Electron. Commun. 2016, 70, 64–69. [CrossRef]
94. Sharma, M.; Awasthi, Y.K.; Singh, H.; Kumar, R.; Kumari, S. Compact printed high rejection triple band-notch UWB antenna with
multiple wireless applications. Eng. Sci. Technol. Int. J. 2016, 19, 1626–1634. [CrossRef]
95. Tang, Z.; Wu, X.; Zhan, J.; Hu, S.; Xi, Z.; Liu, Y. Compact UWB-MIMO Antenna with High Isolation and Triple Band-Notched
Characteristics. IEEE Access 2019, 7, 19856–19865. [CrossRef]
96. Kumar, A.; Ansari, A.Q.; Kanaujia, B.K.; Kishor, J.; Kumar, S. An ultra-compact two-port UWB-MIMO antenna with dual
band-notched characteristics. AEU-Int. J. Electron. Commun. 2020, 114, 152997. [CrossRef]
97. Cho, Y.J.; Kim, K.H.; Choi, D.H.; Lee, S.S.; Park, S.-O. A Miniature UWB Planar Monopole Antenna With 5-GHz Band-Rejection
Filter and the Time-Domain Characteristics. IEEE Trans. Antennas Propag. 2006, 54, 1453–1460. [CrossRef]
98. Ma, T.-G.; Tseng, C.-H. An Ultrawideband Coplanar Waveguide-Fed Tapered Ring Slot Antenna. IEEE Trans. Antennas Propag.
2006, 54, 1105–1110. [CrossRef]
99. Hong, C.-Y.; Ling, C.-W.; Tarn, I.-Y.; Chung, S.-J. Design of a Planar Ultrawideband Antenna with a New Band-Notch Structure.
IEEE Trans. Antennas Propag. 2007, 55, 3391–3397. [CrossRef]
100. Zhang, J.-P.; Xu, Y.-S.; Wang, W.-D. Microstrip-Fed Semi-Elliptical Dipole Antennas for Ultrawideband Communications. IEEE
Trans. Antennas Propag. 2008, 56, 241–244. [CrossRef]
101. Soltani, S.; Azarmanesh, M.; Lotfi, P.; Dadashzadeh, G. Two novel very small monopole antennas having frequency band notch
function using DGS for UWB application. AEU-Int. J. Electron. Commun. 2011, 65, 87–94. [CrossRef]
102. Chitra, R.J.; Nagarajan, V. Double L-slot microstrip patch antenna array for WiMAX and WLAN applications. Comput. Electr. Eng.
2013, 39, 1026–1041. [CrossRef]
Micromachines 2022, 13, 60
44 of 45
103. Kang, L.; Li, H.; Wang, X.; Shi, X. Compact Offset Microstrip-Fed MIMO Antenna for Band-Notched UWB Applications. IEEE
Antennas Wirel. Propag. Lett. 2015, 14, 1754–1757. [CrossRef]
104. Huang, H.; Liu, Y.; Zhang, S.; Gong, S. Uniplanar Differentially Driven Ultrawideband Polarization Diversity Antenna with
Band-Notched Characteristics. IEEE Antennas Wirel. Propag. Lett. 2014, 14, 563–566. [CrossRef]
105. Bakariya, P.S.; Dwari, S.; Sarkar, M. Triple band notch UWB printed monopole antenna with enhanced bandwidth. AEU-Int. J.
Electron. Commun. 2015, 69, 26–30. [CrossRef]
106. Wang, Z.; Liu, J.; Yin, Y. Triple band-notched UWB antenna using novel asymmetrical resonators. AEU-Int. J. Electron. Commun.
2016, 70, 1630–1636. [CrossRef]
107. Yadav, A.; Sethi, D.; Khanna, R. Slot loaded UWB antenna: Dual band notched characteristics. AEU-Int. J. Electron. Commun. 2016,
70, 331–335. [CrossRef]
108. Peng, L.; Wen, B.-J.; Li, X.-F.; Jiang, X.; Li, S.-M. CPW Fed UWB Antenna by EBGs With Wide Rectangular Notched-Band. IEEE
Access 2016, 4, 9545–9552. [CrossRef]
109. Yang, Z.; Jingjian, H.; Weiwei, W.; Naichang, Y. An antipodal Vivaldi antenna with band-notched characteristics for ultra-wideband
applications. AEU-Int. J. Electron. Commun. 2017, 76, 152–157. [CrossRef]
110. Yang, B.; Qu, S. A compact integrated Bluetooth UWB dual-band notch antenna for automotive communications. AEU-Int. J.
Electron. Commun. 2017, 80, 104–113. [CrossRef]
111. Awad, N.M.; Abdelazeez, M.K. Multislot microstrip antenna for ultra-wide band applications. J. King Saud Univ.-Eng. Sci. 2018,
30, 38–45. [CrossRef]
112. Mewara, H.S.; Deegwal, J.K.; Sharma, M.M. A slot resonators based quintuple band-notched Y-shaped planar monopole
ultra-wideband antenna. AEU-Int. J. Electron. Commun. 2018, 83, 470–478. [CrossRef]
113. Yadav, D.; Abegaonkar, M.P.; Koul, S.K.; Tiwari, V.; Bhatnagar, D. A compact dual band-notched UWB circular monopole antenna
with parasitic resonators. AEU-Int. J. Electron. Commun. 2018, 84, 313–320. [CrossRef]
114. Atallah, H.A.; Abdel-Rahman, A.B.; Yoshitomi, K.; Pokharel, R.K. CPW-Fed UWB antenna with sharp and high rejection multiple
notched bands using stub loaded meander line resonator. AEU-Int. J. Electron. Commun. 2018, 83, 22–31. [CrossRef]
115. Mewara, H.S.; Jhanwar, D.; Sharma, M.M.; Deegwal, J.K. A printed monopole ellipzoidal UWB antenna with four band rejection
characteristics. AEU-Int. J. Electron. Commun. 2018, 83, 222–232. [CrossRef]
116. Jaglan, N.; Gupta, S.D.; Thakur, E.; Kumar, D.; Kanaujia, B.K.; Srivastava, S. Triple band notched mushroom and uniplanar EBG
structures based UWB MIMO/Diversity antenna with enhanced wide band isolation. AEU-Int. J. Electron. Commun. 2018, 90,
36–44. [CrossRef]
117. Benavides, J.B.; Lituma, R.A.; Chasi, P.A.; Guerrero, L.F. A Novel Modified Hexagonal Shaped Fractal Antenna with Multi
Band Notch Characteristics for UWB Applications. In Proceedings of the 2018 IEEE-APS Topical Conference on Antennas and
Propagation in Wireless Communications (APWC), Cartagena, Colombia, 10–14 September 2018; pp. 830–833.
118. El-Hameed, A.A.; Wahab, M.; Elboushi, A.; Elpeltagy, M.S. Miniaturized triple band-notched quasi-self complementary fractal
antenna with improved characteristics for UWB applications. AEU-Int. J. Electron. Commun. 2019, 108, 163–171. [CrossRef]
119. Suriya, I.; Anbazhagan, R. Inverted-A based UWB MIMO antenna with triple-band notch and improved isolation for WBAN
applications. AEU-Int. J. Electron. Commun. 2019, 99, 25–33. [CrossRef]
120. Kumar, R.; Kamatham, Y. Fork shaped with inverted L-stub resonator UWB antenna for WiMAX/WLAN rejection band. AEU-Int.
J. Electron. Commun. 2019, 110, 152881. [CrossRef]
121. Sanyal, R.; Sarkar, P.P.; Sarkar, S. Octagonal nut shaped monopole UWB antenna with sextuple band notched characteristics.
AEU-Int. J. Electron. Commun. 2019, 110, 152833. [CrossRef]
122. Kumar, P.; Ali, T.; Pai, M.M.M. Electromagnetic Metamaterials: A New Paradigm of Antenna Design. IEEE Access 2021, 9,
18722–18751. [CrossRef]
123. Modak, S.; Khan, T.; Laskar, R.H. Penta-notched UWB Monopole Antenna Using EBG Structures and Fork-Shaped Slots. Radio
Sci. 2020, 55, 1–11. [CrossRef]
124. Alizadeh, F.; Ghobadi, C.; Nourinia, J.; Abdi, H.; Mohammadi, B. UWB dual-notched planar antenna by utilizing compact open
meander slitted EBG structure. AEU-Int. J. Electron. Commun. 2021, 136, 153715. [CrossRef]
125. Li, W.T.; Hei, Y.Q.; Feng, W.; Shi, X.W. Planar Antenna for 3G/Bluetooth/WiMAX and UWB Applications with Dual Band-Notched
Characteristics. IEEE Antennas Wirel. Propag. Lett. 2012, 11, 61–64. [CrossRef]
126. Yadav, A.; Agrawal, S.; Yadav, R. SRR and S-shape slot loaded triple band notched UWB antenna. AEU-Int. J. Electron. Commun.
2017, 79, 192–198. [CrossRef]
127. Rahman, M.; Khan, W.T.; Imran, M. Penta-notched UWB antenna with sharp frequency edge selectivity using combination of
SRR, CSRR, and DGS. AEU-Int. J. Electron. Commun. 2018, 93, 116–122. [CrossRef]
128. Li, Z.; Yin, C.; Zhu, X. Compact UWB MIMO Vivaldi Antenna with Dual Band-Notched Characteristics. IEEE Access 2019, 7,
38696–38701. [CrossRef]
129. Salamin, M.A.; Ali, W.A.; Das, S.; Zugari, A. Design and investigation of a multi-functional antenna with variable wideband/notched UWB behavior for WLAN/X-band/UWB and Ku-band applications. AEU-Int. J. Electron. Commun. 2019, 111,
152895. [CrossRef]
130. Luo, S.; Chen, Y.; Wang, D.; Liao, Y.; Li, Y. A monopole UWB antenna with sextuple band-notched based on SRRs and U-shaped
parasitic strips. AEU-Int. J. Electron. Commun. 2020, 120, 153206. [CrossRef]
Micromachines 2022, 13, 60
45 of 45
131. Serria, E.A.; Hussein, M.I. Implications of Metamaterial on Ultra-Wide Band Microstrip Antenna Performance. Crystals 2020, 10,
677. [CrossRef]
132. Ebadzadeh, S.R.; Zehforoosh, Y.; Mohammadifar, M.; Zavvari, M.; Mohammady, P. A Compact UWB Monopole Antenna with
Rejected WLAN Band using Split-Ring Resonator and Assessed by Analytic Hierarchy Process Method. J. Microw. Optoelectron.
Electromagn. Appl. 2017, 16, 592–601. [CrossRef]
133. Bakali, H.E.O.E.; Zakriti, A.; Farkhsi, A.; Dkiouak, A.; El Ouahabi, A.M. Design and Realization of Dual Band Notch UWB MIMO
Antenna In 5G And Wi-Fi 6E by Using Hybrid Technique. Prog. Electromagn. Res. C 2021, 116, 1–12. [CrossRef]
134. Zhou, J.-Y.; Wang, Y.; Xu, J.-M.; Du, A.C. A Cpw-Fed Uwb-Mimo Antenna with High Isolation and Dual Band-Notched
Characteristic. Prog. Electromagn. Res. M 2021, 102, 27–37. [CrossRef]
135. Abbas, A.; Hussain, N.; Lee, J.; Park, S.G.; Kim, N. Triple Rectangular Notch UWB Antenna Using EBG and SRR. IEEE Access
2021, 9, 2508–2515. [CrossRef]
136. Wang, S.; Li, K.; Kong, F.; Du, L. A miniaturized triple-band planar antenna combing single-cell metamaterial structure and
defected ground plane for WLAN/WiMAX applications. J. Electromagn. Waves Appl. 2021, 35, 357–370. [CrossRef]
137. Hassan, M.M.; Rasool, M.; Asghar, M.U.; Zahid, Z.; Khan, A.A.; Rashid, I.; Rauf, A.; Bhatti, F.A. A novel UWB MIMO antenna
array with band notch characteristics using parasitic decoupler. J. Electromagn. Waves Appl. 2019, 34, 1225–1238. [CrossRef]
138. Wahab, M.G.; Swelam, W.; Abdeazeem, M. Novel miniaturized UWB antenna with triple band-notched characteristics utilizing
SRR and folded U-shaped slot. In Proceedings of the 2017 Progress in Electromagnetics Research Symposium-Spring (PIERS),
St. Petersburg, Russia, 22–25 May 2017; pp. 1176–1180.
139. Islam, M.M.; Faruque, M.R.I.; Islam, M.; Islam, M.T. A Compact 5.5 GHz Band-Rejected UWB Antenna Using Complementary
Split Ring Resonators. Sci. World J. 2014, 2014, 1–8. [CrossRef]
140. Bernhard, J.T. Reconfigurable Antennas. Synth. Lect. Antennas 2007, 2, 1–66. [CrossRef]
141. Parchin, N.O.; Basherlou, H.J.; Al-Yasir, Y.I.A.; Abd-Alhameed, R.A.; Abdulkhaleq, A.M.; Noras, J.M. Recent Developments of
Reconfigurable Antennas for Current and Future Wireless Communication Systems. Electronics 2019, 8, 128. [CrossRef]
142. Haupt, R.L.; Lanagan, M. Reconfigurable antennas. IEEE Antennas Propag. Mag. 2013, 55, 49–61. [CrossRef]
143. Ali, T.; Pathan, S.; Biradar, R.C. Multiband, frequency reconfigurable, and metamaterial antennas design techniques: Present and
future research directions. Internet Technol. Lett. 2018, 1, e19. [CrossRef]
144. Al-Husseini, M.; Costantine, J.; Christodoulou, C.G.; Barbin, S.E.; El-Hajj, A.; Kabalan, K.Y. A reconfigurable frequency-notched
UWB antenna with split-ring resonators. In Proceedings of the2010 Asia-Pacific Microwave Conference, Yokohama, Japan, 7–10
December 2010; pp. 618–621.
145. Elsheakh, D.N.; Elsadek, H.A.; Abdallah, E.A. Reconfigurable microstrip monopole patch antenna with electromagnetic band-gap
structure design for ultrawideband wireless communication systems. Microw. Opt. Technol. Lett. 2011, 53, 2466–2471. [CrossRef]
146. Naser-Moghadasi, M.; Haraty, M.R.; Momeni, S.M.S.; Virdee, B.S. Novel compact UWB antenna with reconfigurable dual-band
notches using pin diode switches actuated without λg /4 DC bias lines. Microw. Opt. Technol. Lett. 2012, 54, 2392–2397. [CrossRef]
147. Al-Husseini, M.; Safatly, L.; Ramadan, A.; El-Hajj, A.; Kabalan, K.; Christodoulou, C.G. Reconfigurable Filter Antennas for Pulse
Adaptation in UWB Cognitive Radio Systems. Prog. Electromagn. Res. B 2012, 37, 327–342. [CrossRef]
148. Wu, Z.H.; Wei, F.; Shi, X.-W.; Li, W.-T. A Compact Quad Band-Notched UWB Monopole Antenna Loaded One Lateral L-Shaped
Slot. Prog. Electromagn. Res. 2013, 139, 303–315. [CrossRef]
149. Shahine, M.Y.A.; Al-Husseini, M.; Kabalan, K.; El-Hajj, A. Dielectric resonator antennas with band rejection and frequency
reconfigurability. Prog. Electromagn. Res. C 2014, 46, 101–108. [CrossRef]
150. Aghdam, S.A.; Bagby, J.S. Resonator Type for the Creation of a Potentially Reconfigurable Filtering Band in a UWB Antenna.
Prog. Electromagn. Res. Lett. 2015, 52, 17–21. [CrossRef]
151. Horestani, A.K.; Shaterian, Z.; Naqui, J.; Martin, F.; Fumeaux, C. Reconfigurable and Tunable S-Shaped Split-Ring Resonators and
Application in Band-Notched UWB Antennas. IEEE Trans. Antennas Propag. 2016, 64, 3766–3776. [CrossRef]
152. Srivastava, G.; Mohan, A.; Chakrabarty, A. Compact Reconfigurable UWB Slot Antenna for Cognitive Radio Applications. IEEE
Antennas Wirel. Propag. Lett. 2016, 16, 1139–1142. [CrossRef]
153. Verma, A.; Parihar, M.S. Multifunctional Antenna with Reconfigurable Ultra-Wide Band Characteristics. Radioengineering 2017,
26, 647–654. [CrossRef]
154. Toktas, A.; Yerlikaya, M. A compact reconfigurable ultra-wideband G-shaped printed antenna with band-notched characteristic.
Microw. Opt. Technol. Lett. 2019, 61, 245–250. [CrossRef]
155. Magray, M.I.; Muzaffar, K.; Wani, Z.; Singh, R.K.; Karthikeya, G.S.; Koul, S.K. Compact frequency reconfigurable triple band
notched monopole antenna for ultrawideband applications. Int. J. Microw. Comput. Eng. 2019, 29, 21942. [CrossRef]
156. Fertas, K.; Ghanem, F.; Azrar, A.; Aksas, R. UWB antenna with sweeping dual notch based on metamaterial SRR fictive rotation.
Microw. Opt. Technol. Lett. 2020, 62, 956–963. [CrossRef]
157. Shome, P.P.; Khan, T.; Laskar, R.H. CSRR-loaded UWB monopole antenna with electronically tunable triple band-notch characteristics for cognitive radio applications. Microw. Opt. Technol. Lett. 2020, 62, 2919–2929. [CrossRef]
158. Medkour, H.; Cheniti, M.; Narbudowicz, A.; Das, S.; Vandelle, E.; Vuong, T.P. Coplanar waveguide-based ultra-wide band
antenna with switchable filtering of WiMAX 3.5 GHz and WLAN 5 GHz signals. Microw. Opt. Technol. Lett. 2020, 62, 2398–2404.
[CrossRef]