scholarly journals Reconfigurable Polarizer Based on Bulk Dirac Semimetal Metasurface

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 228
Author(s):  
Yannan Jiang ◽  
Jing Zhao ◽  
Jiao Wang
Keyword(s):  
Physical Mechanism ◽  
Axial Ratio ◽  
Polarization Conversion ◽  
Cross Polarization ◽  
Frequency Range ◽  
Dirac Semimetal ◽  
Polarized Waves ◽  
Orthogonal Components ◽  
The Cross ◽  
Conversion Efficiencies

In this paper, we propose a reflective polarizer in terahertz regime, which utilizes the Bulk-Dirac-Semimetal (BDS) metasurface can be dynamically tuned in broadband. The proposed polarizer is capable of converting the linear polarized wave into the circular polarized or the cross polarized waves by adjusting the Fermi energy (EF) of the BDS. In the frequency range of 0.51 THz and 1.06 THz, the incident linear polarized wave is converted into a circular polarized wave with an axial ratio (AR) less than 3 dB when EF = 30 meV. When EF = 45 meV, the cross-polarization conversion is achieved with the polarization conversion ratio (PCR) greater than 90% in the band of 0.57−1.12 THz. Meanwhile, the conversion efficiencies for both polarization conversions are in excess of 90%. Finally, the physical mechanism is revealed by the decomposition of two orthogonal components and the verification is presented by the interference theory.

scholarly journals A New Dual Circularly Polarized Feed Employing a Dielectric Cylinder-Loaded Circular Waveguide Open End Fed by Crossed Dipoles

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jae-Hoon Bang ◽  
Soon-Woo Choi ◽  
Jae-Woo Noh ◽  
Joo-Young Lim ◽  
Dong-Hyun Kim ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Circular Waveguide ◽  
Axial Ratio ◽  
Dielectric Cylinder ◽  
Cross Polarization ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Hybrid Coupler ◽  
The Cross ◽  
Polarized Radiation

This paper presents a new dual circularly polarized feed that provides good axial ratio over wide angles and low cross-polarized radiation in backward direction. A circular waveguide open end is fed with two orthogonally polarized waves in phase quadrature by a pair of printed crossed dipoles and a compact connectorized quadrature hybrid coupler. The waveguide aperture is loaded with a dielectric cylinder to reduce the cross-polarization beyond 90 degrees off the boresight. The fabricated feed has, at 5.5 GHz, 6.33-dBic copolarized gain, 3-dB beamwidth of 106°, 10-dB beamwidth of 195°, 3-dB axial ratio beamwidth of 215°, maximum cross-polarized gain of −21.4 dBic, and 27-dB port isolation. The reflection coefficient of the feed is less than −10 dB at 4.99–6.09 GHz.

scholarly journals Dual-Band Patch Antenna Fed by Meandering Probe for Low Cross-Polarization

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Xiao-Lan Zhao ◽  
Quan Wei Lin
Keyword(s):  
Reflection Coefficient ◽  
Patch Antenna ◽  
Dual Band ◽  
Cross Polarization ◽  
Frequency Range ◽  
Face To Face ◽  
Resonance Modes ◽  
The Cross ◽  
Polarization Level

This paper presents a dual-band patch antenna loaded with face-to-face U-shaped slots fed by a substrate-integrated meandering probe (SIM-probe). With the presence of U-shaped slots, two current paths are formed, which leads to the resonance modes at 2.4 and 3.65 GHz on the patch. The SIM-probe suppresses the unwanted cross-polarization radiations by providing out-of-phase vertical currents from vertical metallic vias. To verify our work, a prototype was fabricated and tested. The proposed antenna achieves the impedance bandwidths of 9.4% and 9% from the frequency range of 2.34–2.57 GHz and 3.5–3.83 GHz (for the reflection coefficient ≤ −10 dB) and obtains average gains of 5.8 dBi and 6.8 dBi at both bands. The cross-polarization level is below −20 dB. Measured results agree well with the simulation.

Linear to left- and right-hand circular polarization conversion by using a metasurface structure

2017 ◽  
Vol 10 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Oguzhan Akgol ◽  
Olcay Altintas ◽  
Emin Unal ◽  
Muharrem Karaaslan ◽  
Faruk Karadag
Keyword(s):  
Axial Ratio ◽  
Wide Band ◽  
Polarization Conversion ◽  
Band Frequency ◽  
Left Handed ◽  
Linear Waves ◽  
Polarized Waves ◽  
Unit Cells ◽  
Linearly Polarized ◽  
Parallel Strips

By using a metasurface (MS) structure, a linearly polarized wave is converted to circularly polarized waves. Both right- and left-handed circular polarizations (RHCPs and LHCP) are obtained by a simple configuration in the proposed structure which consists of 16 unit cells arranged in a 4 × 4 layout. Each unit cell contains five horizontal and parallel strips embedded in a rectangular frame in which a single diagonal strip is placed from one corner to the opposed one. It is shown that the orientation of the diagonal line determines the handedness of the converted signal to be either LHCP or RHCP. In order to show the working conditions of the MS structure, scattering parameters are found for both co-polarized and cross-polarized responses. Axial ratio, an indicator for polarization conversion, is then obtained by dividing cross-polar response to co-polar response to demonstrate the transformation. The structure works for horizontally and vertically polarized linear waves in a wide band frequency range which is approximately 510 MHz. Since the suggested MS model is composed of a simple geometry for polarization conversion, it can be easily adjusted in any desired frequency bands for a variety of applications from the defence industry to medical, education, or communication areas.

scholarly journals Dual-Band Transmissive Cross-Polarization Converter with Extremely High Polarization Conversion Ratio Using Transmitarray

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1827 ◽  
Author(s):  
Jianxing Li ◽  
Jialin Feng ◽  
Bo Li ◽  
Hongyu Shi ◽  
Anxue Zhang ◽  
...  
Keyword(s):  
Cell Structure ◽  
Conversion Ratio ◽  
Transmitted Wave ◽  
Dual Band ◽  
Polarization Conversion ◽  
Cross Polarization ◽  
Polarization Converter ◽  
Linearly Polarized ◽  
The Cross ◽  
Incident Waves

In this paper, a dual-band cross-polarization converter is proposed. The proposed device can convert linearly polarized incident waves to their cross-polarized transmitted waves. Inspired by the aperture coupled transmitarray, a transmissive multi-layered unit cell structure was designed, which can operate in two frequency bands. The designed structure can manipulate the polarization of the transmitted wave into the cross-polarization of the incident waves at 10.36 GHz and 11.62 GHz. The cross-polarized transmittance of the proposed cross-polarization converter is higher than 0.93. In addition, the transmitted wave has an extremely low co-polarized component, which results in a nearly 100% polarization conversion ratio. The two working frequencies can be tuned independently. The proposed cross-polarization converter was simulated, fabricated and measured. The simulation results confirm with the measurement results.

Bi-functional Metasurface Polarizer for Reflected and Transmitted Waves

2021 ◽  
Author(s):  
Xiaojun Huang ◽  
Xia Ma ◽  
Xuewen Li ◽  
Jingdao Fan ◽  
Liang Guo ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Conversion Rate ◽  
Electromagnetic Waves ◽  
Oblique Incidence ◽  
Surface Current ◽  
Axial Ratio ◽  
Polarization Conversion ◽  
Polarized Waves ◽  
Transmitted Waves ◽  
Polarization Converters

Abstract Manipulating the polarizations of electromagnetic waves by flexible and diverse means is desirable for a myriad of microwave systems. More recently, metasurfaces offer the promising alternatives to conventional polarization manipulating components because of the flexibility of their geometry could be arbitrarily customized. In this context, a bi-layered metasurface was presented to simultaneously manipulate the polarized states of reflected and transmitted microwaves. No matter whether the incident electromagnetic wave is x-polarized or y-polarized, the reflected and transmitted waves will be converted into orthogonal y- polarized waves at the operating frequency. The designed metasurface has a high polarization conversion rate(PCR) above 90% for both normal and oblique incidence. The experimental results verify the correctness of the simulated results. Finally, axial ratio and surface current distributions were employed to reveal the physics of polarization manipulation. The proposed metasurface will be beneficial to the design of flexible and versatile polarization converters and has great potential for applications in polarization controlled devices and also is believed extendable to higher frequency regimes.

Design of Transmission Polarization Metasurface Converter

2021 ◽  
Vol 1035 ◽  
pp. 718-723
Author(s):  
Bo Wen Han ◽  
Si Jia Li ◽  
Xiang Yu Cao ◽  
Jun Gao
Keyword(s):  
Simple Structure ◽  
Axial Ratio ◽  
Polarization Conversion ◽  
Current Analysis ◽  
Polarization Converter ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Relative Bandwidth ◽  
Linearly Polarized ◽  
Simulation Results

The transmission polarization metasurface converter is an effective method to realize the polarization manipulation of the transmission waves, and it is also the research hotspot of metasurfaces. A new broadband transmissive polarization converter was proposed based on the metasurfaces converted incident linearly polarized waves into circularly polarized waves of transmission. The top and bottom layers of the unit were axisymmetric metal patches. The top and bottom layers of metal patches were overlapped and the shape was like an arrow. The thickness of the substrate was 4mm. The polarization conversion mechanism of metasurface was illustrated by parameter optimization and current analysis. The simulation results show that when the metasurface works in the frequency band of 6.71GHz~8.45GHz, the linearly polarized incident wave can be converted into a circularly polarized transmitted wave with axial ratio less than 3dB, and the relative bandwidth can reach 23%. The designed polarization converter has a simple structure and the potential application value in electromagnetic wave control of radio frequency devices.

scholarly journals Simple design of efficient broadband multifunctional polarization converter for X-band applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thi Kim Thu Nguyen ◽  
Thi Minh Nguyen ◽  
Hong Quang Nguyen ◽  
Thanh Nghia Cao ◽  
Dac Tuyen Le ◽  
...  
Keyword(s):  
Circular Polarization ◽  
Incident Angle ◽  
Polarization Conversion ◽  
Simple Design ◽  
Cross Polarization ◽  
Polarization Converter ◽  
Frequency Bands ◽  
X Band ◽  
Cost Efficient ◽  
Patch Resonators

AbstractA simple design of a broadband multifunctional polarization converter using an anisotropic metasurface for X-band application is proposed. The proposed polarization converter consists of a periodic array of the two-corner-cut square patch resonators based on the FR-4 substrate that achieves both cross-polarization and linear-to-circular polarization conversions. The simulated results show that the polarization converter displays the linear cross-polarization conversion in the frequency range from 8 to 12 GHz with the polarization conversion efficiency above 90%. The efficiency is kept higher than 80% with wide incident angle up to 45°. Moreover, the proposed design achieves the linear-to-circular polarization conversion at two frequency bands of 7.42–7.6 GHz and 13–13.56 GHz. A prototype of the proposed polarization converter is fabricated and measured, showing a good agreement between the measured and simulated results. The proposed polarization converter exhibits excellent performances such as simple structure, multifunctional property, and large cost-efficient bandwidth and wide incident angle insensitivity in the linear cross polarization conversion, which can be useful for X-band applications. Furthermore, this structure can be extended to design broadband polarization converters in other frequency bands.

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