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Full-Text - Radioengineering
Full-Text - Radioengineering

... lens. The particular parameters and shapes of the lens are illustrated in Fig. 1. The phase center of the irradiating antenna has to be placed in the focal point of the lens so that the spherical electromagnetic wave incides on the inner surface of the lens. The inner surface of the elliptic lens re ...
Folded Dipole Antenna
Folded Dipole Antenna

... • Radiation pattern of conventional half-wave dipole and folded dipole are almost same. • Major difference is in terms of input impedance. • Input impedance of folded dipole is much higher than half wave dipole. • Other 2 parameters relatively different from half wave are directivity and Bandwidth. ...
Discussion
Discussion

Microsoft Word Format - University of Toronto Physics
Microsoft Word Format - University of Toronto Physics

... By "optical pumping", we mean the use of light to change the population of a set of energy levels of a system from the Boltzman distribution at the temperature of the experiment. That is, a system of atomic spin orientations is "pumped" from an equilibrium distribution over magnetic sub-states into ...
Field distributions in the crossover from ballistic to diffusive wave
Field distributions in the crossover from ballistic to diffusive wave

... components of the field is nearly Gaussian, even in samples with thickness less than the scattering mean free path. In these samples, the phase distribution of the residual field, which is the difference between the field and its ensemble average, is nearly flat. The extent of the deviation of the r ...
A UHF/UWB hybrid silicon RFID tag with on–chip
A UHF/UWB hybrid silicon RFID tag with on–chip

... with inductive coupling using a magnetic OCA [14]. With a modulated backscatter technique, the voltage induced into the miniaturised loop antenna was analysed over area and over distance. The power harvesting concept was studied and characterised with a small 3 mm × 1 mm system, where two different ...
The Low Frequency Array active antenna system
The Low Frequency Array active antenna system

mm-Wave Phased Arrays in Silicon with Integrated Antennas E-mail:
mm-Wave Phased Arrays in Silicon with Integrated Antennas E-mail:

Mechanism of angular momentum transfer from microwaves to
Mechanism of angular momentum transfer from microwaves to

... First, the ring is made of copper which is a nearly perfectly reflecting material at this frequency. It is usually assumed that for a perfectly electrical conductor, no AM transfer by reflection could be performed [30–32]. Indeed, following the arguments given in these references, to ensure continui ...
The K9AY Terminated Loop—A Compact, Directional Receiving
The K9AY Terminated Loop—A Compact, Directional Receiving

... The terminated loop was developed after examining the behavior of the EWE. In theory, the EWE is a terminated half-loop. High-frequency directional couplers such as those used in the well-known Bird Thruline wattmeters are constructed similarly, just much smaller.* My analysis determined that a term ...
Comparison of Existing Large Antennas and Future Arrays
Comparison of Existing Large Antennas and Future Arrays

... Many scientific programs, both space based and ground based, are limited by the microwave collecting area on earth. These include communication with distant low-power transmitters, emergency communications with failed spacecraft, microwave long baseline interferometry with spacecraft, and groundbase ...
244065
244065

... the incident intensity |Ei|2 at the focus. The results in Fig. 5 show a confined electric field close to the gap region of the antenna. Also, a large electric field enhancement is observed for all the half-beam angle values α. The intensity enhancement at the center of the antenna is about 1200 for ...
Designing an RF Remote Control
Designing an RF Remote Control

... for optimum transmit power on every button press. With standard remote control designs, variations in the RF transmitter, component and antenna manufacturing tolerances and the environment can lead to large antenna inefficiencies and wasted power. Figure 2 shows a simplified block diagram of the Si4 ...
Designing an RF Remote Control
Designing an RF Remote Control

Optical Pumping of Natural Rubidium
Optical Pumping of Natural Rubidium

... introduced to the sample of natural Rubidium will only induce changes between the ground state and the first excited state. Because this energy is so much larger than the Hyperfine and magnetic splitting energies, the selection rules for F and M still apply (and in fact are the only important select ...
Landau Quantization of Neutral Particles in an External Field
Landau Quantization of Neutral Particles in an External Field

EET422 EMC intro 2008-2009 msw
EET422 EMC intro 2008-2009 msw

... All electrically charged particles are surrounded by electric fields and when the charges are in motion magnetic fields are produced. When the velocity of the charged particle changes an EM field is produced. Historically electromagnetic fields were first discovered in the 19th century when physicis ...
The K9AY Terminated Loop—A Compact, Directional Receiving
The K9AY Terminated Loop—A Compact, Directional Receiving

... The terminated loop was developed after examining the behavior of the EWE. In theory, the EWE is a terminated half-loop. High-frequency directional couplers such as those used in the well-known Bird Thruline wattmeters are constructed similarly, just much smaller.* My analysis determined that a term ...
Si4010 CALCULATOR SPREADSHEET USAGE
Si4010 CALCULATOR SPREADSHEET USAGE

... target can be estimated based on the expected efficiency of the antenna and the desired radiated power target. It represents the total amount of power dissipated in the PA and the antenna.The spreadsheet will always try to hit this target. The result is shown in the Calculated Values section under T ...
to view the Instruction Manual.
to view the Instruction Manual.

GoFree Track
GoFree Track

... The GPS extension requires a different cable. ...
HF OPERATORS MAGNETICS: FERRITES, BEADS and BALUNS
HF OPERATORS MAGNETICS: FERRITES, BEADS and BALUNS

... ! Closed magnetics – i.e. Toroids " The magnetic path is enclosed - internal " Permeability and Inductance is high " Core can saturate, but the ferrite powders are microscopically separated from each other providing a somewhat distributed air gap " Core is self shielding from external fields ...
Direct Characterization of Plasmonic Slot Waveguides and
Direct Characterization of Plasmonic Slot Waveguides and

... the same time, the operation full-width-at-half-maximum (FWHM) bandwidth of the 3DA coupler is smaller than that of the 2DA one. This fact agrees with the usual ...
How to Build a Low-Cost, Extended-Range RFID Skimmer 15
How to Build a Low-Cost, Extended-Range RFID Skimmer 15

... • Attenuate signals before feeding them back to the TI module – Avoid potential reader damage – Still deliver input signals to receiver ...
nAN900-04
nAN900-04

... APPLICATION NOTE nRF905 RF and antenna layout corresponding connection points numbered 1, 2 and 3 on the RF layout with differential connection. The component footprints used in the loop antenna layout are size 0603. The layout of the rest of the communication system may influence the antenna tunin ...
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Near and far field



The near field (or near-field) and far field (or far-field) are regions of the electromagnetic field around an object, such as a transmitting antenna, or the result of radiation scattering off an object. Non-radiative 'near-field' behaviors of electromagnetic fields dominate close to the antenna or scattering object, while electromagnetic radiation 'far-field' behaviors dominate at greater distances. Far-field E and B field strength decreases inversely with distance from the source, resulting in an inverse-square law for the radiated power intensity of electromagnetic radiation. By contrast, near-field E and B strength decrease more rapidly with distance (with inverse-distance squared or cubed), resulting in relative lack of near-field effects within a few wavelengths of the radiator.
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