scholarly journals Ultrathin Spin-Decoupled Meta-Devices for Independent Control of Electromagnetic Waves With Dual-Orthogonal Circular Polarization

2021 ◽  
Vol 8 ◽  
Author(s):  
Wenqiong Chen ◽  
Buxiong Qi ◽  
Jingwei Zhang ◽  
Tiaoming Niu ◽  
Zhonglei Mei
Keyword(s):  
Circular Polarization ◽  
Geometric Phase ◽  
Electromagnetic Waves ◽  
Layer Structure ◽  
Single Layer ◽  
Beam Deflection ◽  
Independent Control ◽  
Circularly Polarized ◽  
Beam Focusing ◽  
Polarized Waves

Inspired by the concept of miniaturized and integrated systems, an ultrathin and multifunctional metasurface device is highly desirable in microwave fields. It is an inherent characteristic that the two spin phase states of electromagnetic waves imparted by the geometric phase are always conjugate symmetric, i.e., the geometric phase produces anti-symmetrical phase responses between dual-orthogonal circular polarization states. So it is extremely crucial to break the conjugate constraints and realize the completely independent control of electromagnetic waves with dual-orthogonal circular polarization. Based on this perspective, ultrathin and bifunctional meta-devices operating in reflection mode are proposed to independently manipulate the left-handed and right-handed circularly polarized waves, which are constructed by anisotropic meta-atoms with synthetical geometric and propagation phases. It is worth noting that the component elements only need a single-layer structure with the thickness of 0.07λ0. Several design samples are presented to achieve functionalities of beam focusing, vortex wave generation, and beam deflection, respectively. Experiments are performed and show good consistence with the simulation results, successfully verifying the performance of the designed metasurfaces. The research results in this paper pave the way to design low-profile and bifunctional devices with independent controls of circularly polarized waves, which is expected to expand the working capacity of metasurfaces to realize complex electromagnetic wave manipulation with a new degree of freedom.

Fission Transmission Linear-to-Circular Polarization Conversion Based on Compact Bi-Layer structure

2016 ◽  
Vol 3 (3) ◽  
pp. 519 ◽  
Author(s):  
Farman Ali Mangi ◽  
Shaoqiu Xiao ◽  
Ghulam Ali Mallah ◽  
Ghulam Fatima Kakepoto ◽  
Imran Memon
Keyword(s):  
Circular Polarization ◽  
Electromagnetic Waves ◽  
Layer Structure ◽  
Normal Incidence ◽  
Dielectric Substrate ◽  
Polarization Conversion ◽  
Novel Approach ◽  
Polarized Waves ◽  
Transmitted Waves ◽  
Resonance Frequencies

<p>A fission transmission linear-to-circular polarization conversion based on bi-layer structure is proposed which is composed of 3 × 3 array to convert linear-to-circular polarized wave. The structure is constructed by half square with “H” shape printed on both sides of the dielectric substrate that are subjected to obtain multi-band at resonance frequencies. The proposed structure realizes the giant circular polarization under the normal incidence for right and left circular polarized waves. After transmission, the incident wave decomposed into two orthogonal linear components have equal magnitudes and 90o phase difference between them. The novel approach of “fission transmission of electromagnetic waves” is firstly introduced to understand the physics of giant circular polarization conversion which is based on the sequence of incident and transmitted waves to generate strong circular dichroism.</p>

scholarly journals WAVEGUIDE FEED NETWORK FOR HORN ANTENNA WITH CIRCULAR POLARIZATION

2021 ◽  
Author(s):  
Stepan Piltyay
Keyword(s):  
Circular Polarization ◽  
Electromagnetic Waves ◽  
Metal Structure ◽  
Horn Antenna ◽  
Variable Cross ◽  
Circularly Polarized ◽  
Maximum Gain ◽  
Left Hand ◽  
Right Hand ◽  
Feed Network

The article presents the methodology for designing and optimizing of feed network for a circularly polarized horn antenna. A horn antenna has a metal structure and consists of a waveguide that has a variable cross-section and an open radiating end. Electromagnetic waves in such antenna are excited by a waveguide that is connected to a horn antenna in through the narrow wall. The proposed feed network of the horn antenna consists of a rectangular waveguide with a slot. In order to obtain the excitation of signals with circular polarization at the output, a slot was cut in the waveguide at an angle of 45º. As a result, the network makes it possible to form the signals with right-hand circular polarization and left-hand circular polarization. The presented design of the horn antenna feed network eliminates the need to develop a separate waveguide device of polarization processing. The designed feed network of the circularly polarized horn antenna can be used at an operating frequency of 8.0 GHz. At these frequency the reflection coefficient is less than −19 dB. The proposed horn antenna provides a maximum gain of 21 dB for right-hand circular polarization and a maximum gain of 10 dB for left-hand circular polarization. Cross-polarization isolation is higher than 10 dB. Therefore, the developed feed network of the horn antenna provides narrowband operating mode at the circular polarization with satisfying electromagnetic polarization characteristics and matching at the frequency of 8 GHz. Developed feed network of the horn antenna with circular polarization can be used in radio engineering systems, which carry out polarization processing of signals.

Wideband Octagonal Dual Circularly Polarized Sub-array Antenna for Ku-Satellite Systems

2021 ◽  
Vol 35 (12) ◽  
pp. 1500-1506
Author(s):  
Khalid. Ibrahim ◽  
Walaa. Hassan ◽  
Esmat Abdallah ◽  
Ahmed Attiya
Keyword(s):  
Circular Polarization ◽  
Antenna Array ◽  
Single Layer ◽  
Array Antenna ◽  
Circularly Polarized ◽  
Branch Line ◽  
Satellite Systems ◽  
Analysis And Design ◽  
Simulation Results ◽  
Ku Band

In this paper the analysis and design of a dual circularly polarized 4×4 antenna array operating in Ku-band are discussed with emphasis on its sequential feeding network. The dual circular polarization is achieved by feeding a stacked octagonal patches with a wideband branch line coupler. The proposed 4×4 antenna array is based on two separate sequential feeding networks for LH and RH circular polarizations. The advantage of the proposed feeding network is that it is implemented on a single layer. Simulation results by using both HFSS and CST are presented for comparison. In addition, experimental verifications are presented.

scholarly journals Dual-Mode Circular Polarization Selective Surface Cell for Single-Layer Dual-Band Circularly Polarized Reflectarray

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Zheng Liu ◽  
Xue Lei ◽  
Jun-Mo Wu ◽  
Zhi-Jian Xu
Keyword(s):  
Circular Polarization ◽  
Three Dimensional ◽  
Discrimination Performance ◽  
Single Layer ◽  
Axial Ratio ◽  
Dual Band ◽  
Dual Mode ◽  
Circularly Polarized ◽  
Cell Rotation ◽  
Measured Efficiency

A dual-mode circular polarization selective surface (CPSS) cell based on a modification of the Pierrot cell is presented for single-layer dual-band circularly polarized (CP) reflectarray antenna design. To achieve dual-mode CP discrimination performance, the improved three-dimensional geometry and the high-order resonances of the CPSS cell are utilized. The required phase shifts in both modes are obtained by varying the cell rotation angle. A single-layer dual-band reflectarray operating with orthogonal CPs has been fabricated and tested. Measured results show the peak gains of 25.2 dBi at 11.6 GHz with 31% 3 dB axial ratio (AR) bandwidth and 26.5 dBi at 14.6 GHz with 32% 3 dB AR bandwidth, respectively. The measured efficiency is 41.2% at 11.6 GHz and 55.5% at 14.6 GHz.

Non-linear Landau damping of electromagnetic cyclotron waves

1971 ◽  
Vol 5 (2) ◽  
pp. 161-176 ◽  
Author(s):  
Jibayo Akinrimisi ◽  
R. N. Sudan
Keyword(s):  
Electromagnetic Waves ◽  
Distribution Functions ◽  
Matrix Elements ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Non Linear ◽  
The Matrix ◽  
Velocity Distribution Functions ◽  
Linear Damping ◽  
Dominant Process

The non-linear scattering of circularly polarized electromagnetic waves is studied. Expressions for matrix elements of interaction are derived and for interacting right-handed circularly polarized waves (whistler waves) the matrix is explicitly calculated for particular velocity distribution functions of electrons. Non-linear damping rates are computed.It is shown that non-linear scattering is not in general a dominant process for whistlers in the magnetosphere.

A multi-layer approach of orthogonally fed circularly polarized microstrip array antenna for enhanced gain

2019 ◽  
Vol 11 (5-6) ◽  
pp. 532-542 ◽  
Author(s):  
Muhammad Asad Rahman ◽  
Eisuke Nishiyama ◽  
Md. Azad Hossain ◽  
Quazi Delware Hossain ◽  
Ichihiko Toyoda
Keyword(s):  
Integrated Circuit ◽  
Layer Structure ◽  
Single Layer ◽  
Array Antenna ◽  
Compact Structure ◽  
Circularly Polarized ◽  
Wireless Applications ◽  
Feed Network ◽  
Microstrip Array ◽  
Microstrip Array Antenna

AbstractA new circularly polarized microstrip array antenna using the orthogonal feed technique is proposed in this paper. The antenna has a multi-layer structure and a new 3-way power divider employing the both-sided microwave integrated circuit technology is designed to configure the feed network of the array. Circular polarization (CP) is realized by creating a quadrature phase difference between orthogonal feed circuits of the patches. The multi-layer structure gives flexibility to adjust the patch spacing that helps to reduce the sidelobe level of the antenna. It is found that the multi-layer structure exhibits a gain of about 2 dB higher than that of a single layer structure by means of sidelobe reduction. The proposed structure also exhibits good CP performances that are verified by a good agreement of measured and simulated results. Simple and compact structure makes the antenna suitable for various wireless applications.

Unusual Properties of Anisotropic Magnetodielectric Metamaterials

2014 ◽  
Vol 1082 ◽  
pp. 46-50
Author(s):  
Yun Xia Dong ◽  
Chun Ying Liu
Keyword(s):  
Electromagnetic Field ◽  
Green Function ◽  
Layer Structure ◽  
Single Layer ◽  
Input Output ◽  
Anisotropic Metamaterials ◽  
Polarized Waves ◽  
Linearly Polarized ◽  
The Green Function ◽  
Green Function Approach

A phenomenological quantization of electromagnetic field is introduced in the presence of the anisotropic magnetodielectric metamaterials. For a single layer structure with the anisotropic metamaterials, input-output relations are derived using the Green-function approach. Based on these relations, the reflectance of the linearly polarized wave through this structure is calculated. The results show different reflectance for different polarized waves and indicate an application of the anisotropic metamaterials to be the reflectors for certain polarized wave. Furthermore it is found that such a structure can realize the resonant gap with the increase of the thickness. Finally the effects of the absorption are considered and we find that the above properties do not change with introduction of the absorption.

Novel High-Gain Circularly Polarized Lens Antenna Using Single-Layer Transmissive Metasurface

Frequenz ◽  
2017 ◽  
Vol 71 (5-6) ◽  
Author(s):  
Yaqiang Zhuang ◽  
Guangming Wang ◽  
Haipeng Li ◽  
Wenlong Guo
Keyword(s):  
Patch Antenna ◽  
Focal Point ◽  
Layer Structure ◽  
Single Layer ◽  
Axial Ratio ◽  
High Gain ◽  
Attractive Alternative ◽  
Lens Antenna ◽  
Circularly Polarized ◽  
Low Profile

AbstractA high-gain lens antenna employing single-layer focusing metasurface (MS) is proposed in this article. The single-layer element achieves a 360° transmission phase range with a transmission magnitude better than 0.9. And the focusing MS consists of 169 elements was designed by utilizing the technique of varying rotation angle to compensate the phase delay. Thus, a lens antenna is constructed by placing a circularly polarized (CP) patch antenna at the focal point of the MS. The fabricated lens antenna demonstrates a good performance of 4.6 % 3-dB axial ratio bandwidth and 6 % 1-dB gain bandwidth, respectively. Moreover, the maximum gain is 18.3 dBic at 15 GHz, which is enhanced by 11.4 dBic compared with the patch antenna. Due to the single-layer structure, this design has a low profile and easy fabrication process compared with the conventional designs, making it an attractive alternative to compact high-gain antenna.

scholarly journals Geometric phase for multidimensional manipulation of photonics spin Hall effect and helicity-dependent imaging

Nanophotonics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1501-1508 ◽  
Author(s):  
XiaoFei Zang ◽  
BingShuang Yao ◽  
Zhen Li ◽  
Yang Zhu ◽  
JingYa Xie ◽  
...  
Keyword(s):  
Hall Effect ◽  
Geometric Phase ◽  
Electromagnetic Waves ◽  
Spin Hall Effect ◽  
Spin States ◽  
Terahertz Waves ◽  
Circularly Polarized ◽  
Left Hand ◽  
Terahertz Region ◽  
Spin Orbit Interactions

AbstractThe spin Hall effect of light, associated with spin-orbit interactions, describes a transport phenomenon with optical spin-dependent splitting, leading to a plethora of applications such as sensing, imaging, and spin-controlled nanophotonics. Although geometric meatsurfaces can mimic photonic spin Hall effect by spatially splitting left-hand circularly polarized and right-hand circularly polarized states of electromagnetic waves with anomalous refraction or reflection angles, the geometric phase generated by metasurfaces hinders metalenses to realize simultaneous focusing of different spin states, limiting further applications. Here, we propose and experimentally demonstrate an approach to realizing a spin Hall metalens that can focus terahertz waves with different spin states and flexibly manipulate spin-dependent focal points in multiple spatial dimensions based on a pure geometric phase. A dielectric metasurface consisting of micropillars with identical shape and different in-plane orientations is designed to realize the multidimensional manipulation of photonics spin Hall effect in terahertz region. Furthermore, helicity-dependent imaging is demonstrated by the terahertz spin Hall metalens. The uniqueness and robust approach for manipulating spin photons may have a significant impact on designing ultra-compact and multifunctional devices and spin photonics devices.

scholarly journals A wideband dual-circularly polarized traveling wave antenna array

2021 ◽  
Vol 72 (6) ◽  
pp. 407-412
Author(s):  
Jia-Lin Li ◽  
Long-Jie Wang ◽  
Jin Liu ◽  
Kexin Song ◽  
Ye Jin ◽  
...  
Keyword(s):  
Circular Polarization ◽  
Antenna Array ◽  
Phase Difference ◽  
Linear Polarization ◽  
Traveling Wave ◽  
Beam Deflection ◽  
Impedance Bandwidth ◽  
Circularly Polarized ◽  
Wave Antenna ◽  
Traveling Wave Antenna

Abstract A dual-circularly polarized traveling wave antenna based on linear polarization array with wideband response is proposed. The circular polarization is realized by the sequential rotation arrangement of four linear polarization elements and series feeding with a phase difference 90°. Rotating four of such subarrays sequentially with a phase difference of 90° not only broadens the axial ratio (AR) bandwidth but also corrects the pattern beam deflection. Left-handed circular polarization (LHCP) and right-handed circular polarization (RHCP) are respectively achieved by exciting two different ports. The measured impedance bandwidth of the developed antenna array is 27.5 %. The 3-dB AR bandwidths of RHCP and LHCP are respectively 20.7 % and 22.4 % with the peak gains of about 8.7 and 8.3 dBic.

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