Download BDTIC Application Note No. 017

A pp li c a t i o n N o t e , R e v . 2 . 0 , O c t . 2 00 6
A p p li c a t i o n N o t e N o . 0 1 7
A Lo w - N o i s e - A m p l i f i e r w i t h g o o d I P 3o u t p e r fo r m a n c e a t 1 . 9 G H z u s i n g B F P 42 0
BDTIC
R F & P r o t e c ti o n D e v i c e s
www.BDTIC.com/infineon
BDTIC
Edition 2006-10-27
Published by
Infineon Technologies AG
81726 München, Germany
© Infineon Technologies AG 2009.
All Rights Reserved.
LEGAL DISCLAIMER
THE INFORMATION GIVEN IN THIS APPLICATION NOTE IS GIVEN AS A HINT FOR THE IMPLEMENTATION
OF THE INFINEON TECHNOLOGIES COMPONENT ONLY AND SHALL NOT BE REGARDED AS ANY
DESCRIPTION OR WARRANTY OF A CERTAIN FUNCTIONALITY, CONDITION OR QUALITY OF THE
INFINEON TECHNOLOGIES COMPONENT. THE RECIPIENT OF THIS APPLICATION NOTE MUST VERIFY
ANY FUNCTION DESCRIBED HEREIN IN THE REAL APPLICATION. INFINEON TECHNOLOGIES HEREBY
DISCLAIMS ANY AND ALL WARRANTIES AND LIABILITIES OF ANY KIND (INCLUDING WITHOUT
LIMITATION WARRANTIES OF NON-INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF ANY
THIRD PARTY) WITH RESPECT TO ANY AND ALL INFORMATION GIVEN IN THIS APPLICATION NOTE.
Information
For further information on technology, delivery terms and conditions and prices please contact your nearest
Infineon Technologies Office (www.infineon.com).
Warnings
Due to technical requirements components may contain dangerous substances. For information on the types in
question please contact your nearest Infineon Technologies Office.
Infineon Technologies Components may only be used in life-support devices or systems with the express written
approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure
of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support
devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain
and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may
be endangered.
www.BDTIC.com/infineon
Application Note No. 017
A Low-Noise-Amplifier with good IP3out-performance at 1.9 GHz using BFP420
Revision History: 2006-10-27, Rev. 2.0
Previous Version: 2000-07-27
Page
Subjects (major changes since last revision)
All
Document layout change
BDTIC
Trademarks
SIEGET® is a registered trademark of Infineon Technologies AG.
Application Note
3
www.BDTIC.com/infineon
Rev. 2.0, 2006-10-27
Application Note No. 017
Low-Noise-Amplifier with good IP3out performance at 1.9 GHz using BFP420
1
Low-Noise-Amplifier with good IP3out performance at 1.9 GHz
using BFP420
This application note describes a low noise amplifier at 1.9 GHz using SIEMENS SIEGET® 25 BFP420. The
design emphasis has been on achieving a high output intercept point. General information, circuit schematic, PCB
layout and components list are shown below together with measured performance data.
Data at 1.9 GHz (3 V and 20 mA)
Gain:
15 dB
IP3out:
NF:
RLin-out:
23 dB
1.9 dB
BDTIC
>15 dB
+3V
C5=100pF
C6=10nF
R1=27 Ohm
C4=22pF
R3=5.6k
TrL5
C3=100pF
C2=3.3pF
RFout
TrL4
R2=18 Ohm
C1=1.8pF
RFin
Tr1=BFP420
TrL1
TrL2
TrL3
AN017_application.vsd
Figure 1
Application
This amplifier at 1.9 GHz is realized by using microstrip lines as matching elements. The design offers a good
compromise between high IP3 values, low noise figure- and high return loss values.
In order to optimize the design for a particular application please observe the following points:
•
•
•
•
•
The layout size can be reduced by using chip-inductors instead of the microstrip lines TrL and TrL4
Improved stabilization behaviour versus temperature reduced variation in amplifier performance due to the
device‘s Beta (current gain) distribution can be achieved by using an active bias circuit. Such a circuit is
available as a single device from Infineon - BCR400W. For further information please refer to Application Note
No.14. However, in most applications, sufficient stabilization is achievable using the resistors R1 and R2.
This circuit is not optimized, it is only meant as a first step to a good design. The measured figures include
losses of SMA-connectors and the relatively high loss of the microstrip lines on the epoxy-board.
The use of teflon material would provide an improvement of ≅ 0.1 dB.
Resistor R2 is used to improve RF-circuit-stability and return loss values at the output. It also affects the output
intermodulation performance.
Application Note
4
www.BDTIC.com/infineon
Rev. 2.0, 2006-10-27
Application Note No. 017
Low-Noise-Amplifier with good IP3out performance at 1.9 GHz using BFP420
scale 1:1
dim.: 25mm x 20mm
plated thru
holes d=0.5mm
18
3.3 pF
BDTIC
BFP420
1.8 pF
100 pF
22 pF
100 pF
10nF
5.6k
27
AN017_PCB_Layout.vsd
Figure 2
PCB Layout and Component Placement
Application Note
5
www.BDTIC.com/infineon
Rev. 2.0, 2006-10-27
Application Note No. 017
Low-Noise-Amplifier with good IP3out performance at 1.9 GHz using BFP420
Table 1
Component
Component
Value
Unit
Size
Comment
R1
27
Ω
0603
Bias / collector-resistance / VR ≅ 0.5 V
R2
18
Ω
0603
To improve stability and output return loss
R3
5.6
kΩ
0603
Bias / base-resistor
C1
1.8
pF
0603
Input match
C2
3.3
pF
0603
Output match
C3
100
pF
0603
RF-short
C4
22
pF
0603
Output match
C5
100
pF
0603
RF-short
BDTIC
C6
10
nF
Tr1
0603
RF-short
SOT343
SIEGET® BFP420
TrL1
Input match, w = 0.95 mm
TrL2
Emitter-microstrip-line, w = 0.95 mm
TrL3
Emitter-microstrip-line, w = 0.95 mm
TrL4
Input match and DC-bias, w = 0.3 mm
TrL5
Substrate
Application Note
Output match and DC-bias, w = 0.3 mm
H = 0.5 mm, εr = 4.5
FR4
6
www.BDTIC.com/infineon
Rev. 2.0, 2006-10-27
Application Note No. 017
Low-Noise-Amplifier with good IP3out performance at 1.9 GHz using BFP420
Measurements
S21 LOG MAG.
S12 LOG MAG.
10.000 dB/DIV
10.000 dB/DIV
1
BDTIC
1
0.100000
3.000000
GHz
0.100000
S11 LOG MAG.
10.000 dB/DIV
GHz
10.000 dB/DIV
S22 LOG MAG.
1
1
GHz
0.100000
1
3.000000
0.100000
3.000000
3.000000
GHz
1.9 GHz
AN017_M easurem ents.vsd
Figure 3
Measurements
Application Note
7
www.BDTIC.com/infineon
Rev. 2.0, 2006-10-27