Numerical and experimental study of a novel circularly polarized antenna for near-field and far-field communication systems

2016 ◽  
Author(s):  
T. Yamagajo ◽  
M. Kai
Keyword(s):  
Experimental Study ◽  
Communication Systems ◽  
Near Field ◽  
Far Field ◽  
Circularly Polarized

scholarly journals Near-Field to Far-Field Transformation Techniques with Spiral Scannings: A Comprehensive Review

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Renato Cicchetti ◽  
Francesco D’Agostino ◽  
Flaminio Ferrara ◽  
Claudio Gennarelli ◽  
Rocco Guerriero ◽  
...  
Keyword(s):  
Communication Systems ◽  
Near Field ◽  
Theoretical Background ◽  
Wireless Communication Systems ◽  
Far Field ◽  
Unified Theory ◽  
Transformation Techniques ◽  
Positioning Systems ◽  
Rotational Surface ◽  
Spiral Scanning

An overview of the near-field-far-field (NF-FF) transformation techniques with innovative spiral scannings, useful to derive the radiation patterns of the antennas commonly employed in the modern wireless communication systems, is provided in this paper. The theoretical background and the development of a unified theory of the spiral scannings for quasi-spherical and nonspherical antennas are described, and an optimal sampling interpolation expansion to evaluate the probe response on a quite arbitrary rotational surface from a nonredundant number of its samples, collected along a proper spiral wrapping it, is presented. This unified theory can be applied to spirals wrapping the conventional scanning surfaces and makes it possible to accurately reconstruct the NF data required by the NF-FF transformation employing the corresponding classical scanning. A remarkable reduction of the measurement time is so achieved, due to the use of continuous and synchronized movements of the positioning systems and to the reduced number of needed NF measurements. Some numerical and experimental results relevant to the spherical spiral scanning case when dealing with quasi-planar and electrically long antennas are shown.

scholarly journals Helicity-delinked manipulations on surface waves and propagating waves by metasurfaces

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3473-3481 ◽  
Author(s):  
Shiqing Li ◽  
Zhuo Wang ◽  
Shaohua Dong ◽  
Sixiong Yi ◽  
Fuxin Guan ◽  
...  
Keyword(s):  
Surface Waves ◽  
Near Field ◽  
Far Field ◽  
Proof Of Concept ◽  
Circularly Polarized ◽  
Propagating Waves ◽  
Very High ◽  
Opposite Helicity

AbstractAlthough many approaches have been proposed to manipulate propagating waves (PWs) and surface waves (SWs), usually each operation needs a separate meta-device, being unfavorable for optical integrations. Here, we propose a scheme to design a single meta-device that can efficiently generate SWs and/or PWs with pre-designed wavefronts, under the excitations of circularly polarized (CP) PWs with different helicity. As a proof of concept, we design and fabricate a microwave meta-device and experimentally demonstrate that it can convert incident CP waves of opposite helicity to SWs possessing different wavefronts and traveling to opposite directions, both exhibiting very high efficiencies. We further generalize our scheme to design a meta-device and numerically demonstrate that it can either excite a SW beam with tailored wavefront or generate a far-field PW with pre-designed wavefront, as shined by CP waves with different helicity. Our work opens the door to achieving simultaneous controls on far- and near-field electromagnetic environments based on a single ultra-compact platform.

Experimental Study of the Properties of Near-Field and Far-Field Jet Noise

2006 ◽  
Author(s):  
Sébastien Barré ◽  
Vincent Fleury ◽  
Christophe Bogey ◽  
Christophe Bailly ◽  
Daniel Juve
Keyword(s):  
Experimental Study ◽  
Near Field ◽  
Jet Noise ◽  
Far Field

scholarly journals Experimental Study of the Spectral Properties of Near-Field and Far-Field Jet Noise

2007 ◽  
Vol 6 (2) ◽  
pp. 73-92 ◽  
Author(s):  
Christophe Bogey ◽  
Sébastien Barré ◽  
Vincent Fleury ◽  
Christophe Bailly ◽  
Daniel Juvé
Keyword(s):  
Experimental Study ◽  
Spectral Properties ◽  
Near Field ◽  
Jet Noise ◽  
Far Field

scholarly journals Near-Field HF-RFID and CMA-Based Circularly Polarized Far-Field UHF-RFID Integrated Tag Antenna

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Arnon Sakonkanapong ◽  
Chuwong Phongcharoenpanich
Keyword(s):  
Near Field ◽  
Axial Ratio ◽  
Dual Band ◽  
Mode Analysis ◽  
Impedance Bandwidth ◽  
Far Field ◽  
Uhf Rfid ◽  
Characteristic Mode ◽  
Rfid Tag ◽  
Circularly Polarized

This research proposes an integrated high-frequency (HF) and ultrahigh-frequency (UHF) passive radio frequency identification (RFID) tag antenna for near-field (13.56 MHz) and far-field (920–925 MHz) communication. This tag antenna is advantageous for the applications with lossy material in the near-field communication and mitigates polarization loss in the far-field communications. The HF-RFID tag antenna is of square spiral structure, and the circularly polarized UHF-RFID structure consists of a square loop radiator with cascading loop feeding and shorted stub. The structure of HF-RFID tag antenna situated inside the circularly polarized UHF-RFID tag can avoid the significant effect of the near-field magnetic coupling from the square loop. The UHF-RFID tag antenna is realized by using characteristic mode analysis for wideband circular polarization. The HF-RFID structure is conjugate-matched with NXP NT3H2111 chip, and the UHF-RFID structure is conjugate-matched with NXP G2X chip. Simulations were carried out, and an antenna prototype was fabricated. The experimental results reveal that the radiation pattern of UHF-RFID tag antenna is bidirectional with a gain of 0.31 dBic. The impedance bandwidth covers the frequency range of 903–944 MHz, and the axial ratio in boresight direction at 922.5 MHz is 1.67 dB, with the axial ratio bandwidth over 863–938 MHz. The maximum near-field and far-field reading ranges are 4.9 cm and 8.7 m. The proposed integrated dual-band passive tag antenna is operationally ideal for HF-RFID and UHF-RFID applications.

scholarly journals Faulty antenna detection in a linear array using simulated annealing optimization

2020 ◽  
Vol 19 (3) ◽  
pp. 1340
Author(s):  
Navaamsini Boopalan ◽  
Agileswari K. Ramasamy ◽  
Farrukh Hafiz Nagi
Keyword(s):  
Simulated Annealing ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Communication Systems ◽  
Linear Array ◽  
Near Field ◽  
Optimization Method ◽  
Random Permutation ◽  
Far Field ◽  
Planar Array

<span lang="EN-US">Sonar, radar and communication systems solely depend on antenna arrays for signal attainment. These arrays are capable of producing directional signals which can be steered in a certain direction. Faulty elements in an array will result in distorted radiation pattern with increased sidelobe levels.  Far-field faulty antenna detection is necessary due to the near field repairing at complex systems like spacecraft. This paper proposes simulated annealing (SA) optimizing method to find the faulty element’s location in a linear array. In this study, a Chebyshev array is presented with the SA optimization method to detect faulty element location with a random permutation of failure locations tested. This method can successfully detect faulty antenna in a linear array. Even though, this method is developed for linear array it can easily be adapted to a planar array.</span>

Magnetic Tag Antenna for UHF Near-field and Far-Field RFID Applications

2015 ◽  
Vol 5 (2) ◽  
pp. 119
Author(s):  
Mondher Dhaouadi ◽  
M. Mabrouk ◽  
T. Vuong ◽  
A. Ghazel
Keyword(s):  
Near Field ◽  
Far Field ◽  
Rfid Applications
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