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 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 Design of a Small-Size Broadband Circularly Polarized Microstrip Antenna Array

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Pingyuan Zhou ◽  
Zhuo Zhang ◽  
Mang He ◽  
Yihang Hao ◽  
Chuanfang Zhang
Keyword(s):  
Reflection Coefficient ◽  
Antenna Array ◽  
Patch Antenna ◽  
Microstrip Antenna ◽  
Axial Ratio ◽  
Satellite Communications ◽  
Lateral Size ◽  
Circularly Polarized ◽  
Feeding Technique ◽  
Microstrip Antenna Array

A small-size 2×2 broadband circularly polarized microstrip antenna array is proposed in this article. The array has four broadband dual-feed U-slot patch antenna elements with circular polarization, and the sequential feeding technique is used to further enhance the 3 dB axial ratio bandwidth. The lateral size of the fabricated array is as small as 1.33λ0×1.33λ0, and the profile is only 0.04λ0. Measured results show that the overlapped −10 dB reflection coefficient and the 3 dB AR bandwidth is 53%, and the variation of the measured realized gain is less than 1 dB for S-band satellite communications (1.98–2.2 GHz).

A Novel Right Handed Circular Polarization Folded Reflectarray Antenna at 60 GHz

2017 ◽  
Vol 7 (3) ◽  
pp. 1580
Author(s):  
Mohd Fairus Mohd Yusoff ◽  
Ronan Sauleau ◽  
Zaharah Johari ◽  
Mohamad Kamal A. Rahim ◽  
Huda A. Majid
Keyword(s):  
Reflection Coefficient ◽  
Circular Polarization ◽  
Axial Ratio ◽  
Unit Cell ◽  
60 Ghz ◽  
Radiation Patterns ◽  
Circularly Polarized ◽  
Left Handed ◽  
Antenna Directivity ◽  
Reflectarray Antenna

A novel right-handed circular polarization (RHCP) folded reflectarray antenna with optimized parameters is presented at 60GHz. The RHCP folded reflectarray antenna is designed using left handed circularly polarized selective surface (LHCPSS) Pierrot unit cell. Through simulation, it is shown that the antenna operates well at 60GHz. The maximum antenna directivity is 19dB with a reflection coefficient below -15dB. The radiation patterns showed good responses with side lobes level below -10dB. In addition, the best axial ratio at 60GHz is achieved as 0.75dB.

scholarly journals A Wide-Band Circularly Polarized Wide-Gap Antenna Loaded with a Y-Shaped Metal Strip for L-Band Application

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Chun-Ying Kang ◽  
Shu Lin ◽  
Hua Zong ◽  
Zhi-Hua Zhao ◽  
Xue-Ying Zhang
Keyword(s):  
Satellite Communication ◽  
Axial Ratio ◽  
Wide Band ◽  
Metal Strip ◽  
Impedance Bandwidth ◽  
Circularly Polarized ◽  
L Band ◽  
Circularly Polarized Radiation ◽  
Wide Gap ◽  
Polarized Radiation

A wide-band circularly polarized wide-gap antenna loaded with a Y-shaped metal strip applied to L-band is proposed in this paper. The Y-shaped metal strip coupling motivates the wide gap to achieve wide-band circularly polarized radiation. Both the simulated results by CST Microwave Studio and the measured results indicate that the antenna impedance bandwidth (reflection coefficient less than −10 dB) and axial ratio bandwidth (AR < 3 dB) are 35.9% (1.1–1.71 GHz). The antenna produces a dual circularly polarized radiation with gain of 0.8–3.2 dBic. The equivalent current array model of the antenna is also presented, which well explains the radiation characteristics of the antenna. The introduction of the metal reflecting plate makes the antenna a directional one, whose gain is above 4 dBic within the band. This design enables the satellite communication for most frequency bands with high gain, which has a vast potential for future development.

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.

scholarly journals A Slotted Single Feed Circularly Polarized Microstrip Patch Antenna with Suppressed Surface Wave Losses for WLAN Applications

2019 ◽  
Vol 9 (1S) ◽  
pp. 246-248
Keyword(s):  
Patch Antenna ◽  
Microstrip Antenna ◽  
Axial Ratio ◽  
Microstrip Patch Antenna ◽  
Antenna Structure ◽  
Circularly Polarized ◽  
Microstrip Patch ◽  
Circular Patch Antenna ◽  
Circularly Polarized Radiation ◽  
Polarized Radiation

The circularly polarized microstrip antenna has been of great importance in WLAN applications. A circularly polarized slotted circular patch antenna with co-axial feed geometry has been designed to meet the requirements. The antenna designed has been slotted at several locations to make it radiate circularly polarized radiation. Two metallic cylindrical vias have been inserted near the two diametric ends of the slot to improve the realized gain of the antenna. The antenna structure is resonating at 6.4 GHz with 3dB axial ratio bandwidth of 200MHz and gain of 9.8dB has been observed.

scholarly journals Coplanar Waveguide-Fed Bidirectional Same-Sense Circularly Polarized Metasurface-Based Antenna

2021 ◽  
Vol 21 (3) ◽  
pp. 210-217
Author(s):  
Cho Hilary Scott Nkimbeng ◽  
Heesu Wang ◽  
Ikmo Park
Keyword(s):  
Reflection Coefficient ◽  
Coplanar Waveguide ◽  
Ground Plane ◽  
Axial Ratio ◽  
Radiation Efficiency ◽  
Impedance Bandwidth ◽  
Antenna Gain ◽  
Circularly Polarized ◽  
Feed Line

This paper presents the design of a bidirectional same-sense circularly polarized (CP) antenna that uses metasurfaces. The antenna consists of two metasurfaces, each comprising an array of 2 × 4 corner truncated patches placed back-to-back on the top and bottom of the antenna. In addition, a ground plane with an etched slot is sandwiched between the substrates at the front and back, and the feed line is a 50 Ω coplanar waveguide. The antenna radiates same-sense right-handed CP waves in both the front and back directions and has overall dimensions of 48 mm × 24 mm × 3.048 mm (0.91λo × 0.45λo × 0.05λo at 5.7 GHz). The measured reflection coefficient for |S11| < -10 dB yields an impedance bandwidth of 5.21–6.26 GHz (18.4%) and an axial ratio (AR) bandwidth of 5.36–6 GHz (11.2%) for both front and back directions. The antenna gain is 3–5.29 dBic for both directions and has a radiation efficiency of >96% within its AR bandwidth.

Wideband Inverted-L Microstrip-via-Fed Circularly Polarized Antenna with Asymmetrical Ground for WLAN/Wimax Applications

Frequenz ◽  
2018 ◽  
Vol 72 (7-8) ◽  
pp. 333-341 ◽  
Author(s):  
Qiang Chen ◽  
Hou Zhang ◽  
Lu-chun Yang ◽  
Bin-bin Li ◽  
Xue-liang Min
Keyword(s):  
Circular Polarization ◽  
Parametric Study ◽  
Ground Plane ◽  
Axial Ratio ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Circularly Polarized ◽  
Large Bandwidth ◽  
Circularly Polarized Radiation ◽  
Polarized Radiation

Abstract A design with wideband and circularly polarized radiation antenna from an open-slot antenna has been demonstrated in this paper. The proposed antenna, which consists of an open slot and an inverted-L strip feeding, provides a large bandwidth, which completely cover the Wimax (3.3–3.8 GHz) and WLAN (2.4–2.48 GHz) bands. The open slot is formed by an modified ground plane with a slit cut and monofilar spiral stubs employed, which fed by an asymmetrical inverted-L strip feedline using a via. As demonstrated, the CP operation was significantly improved by loading monofilar spiral stubs connected to the asymmetric feedline by means of a via. A parametric study of the key parameters is made and the mechanism for circular polarization is described. After optimization, the impedance bandwidth is approximately 3.78 GHz (2.12 to 5.9 GHz) and the 3 dB axial ratio bandwidth is approximately 2.75 GHz (2.2 to 4.95 GHz), which represent fractional bandwidths of approximately 94.3 % and 76.9 %, respectively.

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