scholarly journals Virtual Singular Scattering of Electromagnetic Waves in Transformation Media Concept

2012 ◽  
Vol 1 (1) ◽  
pp. 38
Author(s):  
M. Y. Barabanenkov ◽  
Y. N. Barabanenkov ◽  
S. A. Nikitov
Keyword(s):  
Green Function ◽  
Free Space ◽  
Electromagnetic Waves ◽  
Scattering Amplitude ◽  
Near Field ◽  
Empty Space ◽  
Resonance Scattering ◽  
Field Zone ◽  
Left Handed ◽  
Veselago Medium

If a scatterer and an observation point (receive) both approach the so-called near field zone of a source of electromagnetic waves, the scattering process becomes singular one which is mathematically attributed to the spatial singularity of the free space Green function at the origin. Starting from less well known property of left-handed material slab to transfer the singularity of the free space Green function by implementing coordinate transformation, we present a phenomenon of virtual singular scattering of electromagnetic wave on an inhomogeneity located in the volume of left – handed material slab. Virtual singular scattering means that a scatterer is situated only virtually in the near field zone of a source, being, in fact, positioned in the far field zone. Such a situation is realized if a scatterer is embedded into a flat Veselago’s lens and approaches the lens’s inner focus because a slab of Veselago medium produces virtual sources inside and behind the slab and virtual scatterer (as a source of secondary waves) from both slab sides. Considering a line-like dielectric scatterer we demonstrate that the scattering efficiency is proportional to product of singular quasistatic parts of two empty space Green functions that means a multiplicative quasistatic singularity of the Green function for a slab of inhomogeneous Veselago medium. We calculate a resonance value of the scattering amplitude in the regime similar to the known Mie resonance scattering.

scholarly journals Listening to NFC at higher harmonic frequencies

Radiotekhnika ◽  
2021 ◽  
pp. 99-104
Author(s):  
V.G. Kryzhanovskyi ◽  
S.P. Serhiienko ◽  
D.V. Chernov ◽  
V.V. Kryzhanovsky
Keyword(s):  
Information Exchange ◽  
Electromagnetic Waves ◽  
Near Field ◽  
Harmonic Signal ◽  
Field Zone ◽  
Third Harmonic ◽  
The Third ◽  
Narrow Bandwidth ◽  
Simulation And Experiment ◽  
High Level

The widespread use of the NFC technology (Near Field Communication) arouses interest to various security aspects. There are known examples of information exchange with card at a distance greater than standard 5-10 cm. It is also interesting to use signals of higher harmonics, which potentially may be radiated in the form of electromagnetic waves, rather than exists as a magnetic field of scattering. In this work, the radiation of third harmonic by card of standard ISO 14443-3А with the fundamental frequency 13.56 MHZ for various excitation modes using the RFID-RC522 reader, smartphone Sony Xperia Z5 Premium, and continuous 10% amplitude modulated 13.56 MHz signal from generator with the subcarrier of imitated smart card response 847.5 kHz was investigated. The card response at third harmonic was simulated in circuit analysis software. Both simulation and experiment proved, that the third harmonic with its side frequencies 40,68 ± 0,8475 MHz have the highest level after the fundamental. To receive the third harmonic signal, the resonant loop antenna in the form of ring vibrator loaded on capacitor was used. This allows the sizes of the received system to be reduced, but the problem of complex field structure in the near-field zone remains. Due to narrow bandwidth of the receiver antenna, the registration of card response signal was complicated. The experiments with three methods of signal generation proved, that third-harmonic signal is registered at the distance more than 1.5m, which may pose a threat for contactless smart-cards transactions security. At the same time, the influence of high level of noise at such a distance may cause difficulties to decode the short-duration signals, which requires further study.

scholarly journals Roll-to-Roll In-Line Implementation of Microwave Free-Space Non-Destructive Evaluation of Conductive Composite Thin Layer Materials

2021 ◽  
Vol 11 (1) ◽  
pp. 378
Author(s):  
Grigorios Koutsoukis ◽  
Ivan Alic ◽  
Antonios Vavouliotis ◽  
Ferry Kienberger ◽  
Kamel Haddadi
Keyword(s):  
Thin Film ◽  
Composite Materials ◽  
Free Space ◽  
Near Field ◽  
Line Production ◽  
Roll To Roll ◽  
Corrugated Horn ◽  
Evaluation Module ◽  
Microwave Nondestructive Testing ◽  
Non Destructive

A free-space microwave nondestructive testing and evaluation module is developed for the low-power, non-ionizing, contactless, and real-time characterization of doped composite thin-film materials in an industrial context. The instrumentation proposed is built up with a handled vector network analyzer interfaced with corrugated horn antennas to measure the near-field complex reflection S11 of planar prepreg composite materials in a roll-to-roll in-line production line. Dedicated modeling and calibrations routines are developed to extract the microwave conductivity from the measured microwave signal. Practical extraction of the radiofrequency (RF) conductivity of thin film prepreg composite materials doped with nano-powders is exemplary shown at the test frequency of 10 GHz.

Near-field zone analysis of the Faraday rotation of magneto-optical thin films

2000 ◽  
Vol 88 (5) ◽  
pp. 2541-2547 ◽  
Author(s):  
N. Richard ◽  
A. Dereux ◽  
E. Bourillot ◽  
T. David ◽  
J. P. Goudonnet ◽  
...  
Keyword(s):  
Thin Films ◽  
Faraday Rotation ◽  
Near Field ◽  
Field Zone

Electromagnetic waves refraction on the interface of transparent with absorptive right or left-handed media

2011 ◽  
Vol 103 (3) ◽  
pp. 635-639 ◽  
Author(s):  
Nicolas L. Dmitruk ◽  
Alexander V. Korovin
Keyword(s):  
Electromagnetic Waves ◽  
Left Handed
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