A Wideband Tightly Coupled Wide-angle Impedance Matching Layer

2019 ◽  
Author(s):  
Yan Li ◽  
Shaoqiu Xiao ◽  
Zhangjing Wang
Keyword(s):  
Impedance Matching ◽  
Wide Angle ◽  
Matching Layer ◽  
Tightly Coupled

scholarly journals Design of an S-Band Phased Array with Modified Dipoles

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Meng Xiang ◽  
Yu Xiao ◽  
Bin Xi ◽  
Yue Zhang ◽  
Shiyou Xu
Keyword(s):  
Antenna Array ◽  
Impedance Matching ◽  
Equivalent Circuit Model ◽  
High Gain ◽  
Wide Angle ◽  
Cross Polarization ◽  
Matching Layer ◽  
Unit Cells ◽  
Operating Bandwidth ◽  
Polarization Level

A wideband, low cross-polarization, high-gain, and wide-angle scanning antenna array is presented in this paper. The antenna array contains 8 subarrays in the horizontal dimension, and each subarray contains 4 unit cells. A two-side printed dipole with an amendatory equivalent circuit model is adopted, and the metal vias are introduced in the element design to ameliorate the cross-polarization level. A radome, acting as the wide-angle impedance matching layer, is introduced to achieve wide-angle scanning. A prototype of a 4 × 8 array is fabricated and measured. The results show that the operating bandwidth of aperture efficiency (BWAE) above 60% is about 26.7% from 2.6 GHz to 3.4 GHz. The measured scanning loss in the H-plane is 2.7 dB when scanning up to 60° with active voltage standing wave ratio (VSWR) <3, and the gain can achieve 21 dB at 3 GHz with a cross-polarization level below −30 dB at all angles.

A Wideband and Wide Scanning Tightly Coupled Dipole Array with Meta-Surface Wide-Angle Impedance Matching

2021 ◽  
Vol 36 (7) ◽  
pp. 872-878
Author(s):  
Yuan Ye ◽  
Zhao Huang ◽  
Yun Jiang ◽  
Li-an Bian ◽  
Chang Zhu ◽  
...  
Keyword(s):  
Antenna Array ◽  
Massive Mimo ◽  
Low Cost ◽  
Impedance Matching ◽  
Ultra Wideband ◽  
Wide Angle ◽  
Scanning Angle ◽  
Low Profile ◽  
Tightly Coupled ◽  
Mimo Beamforming

A low profile ultra-wideband tightly coupled dipole array is studied. The antenna elements are fed by Marchand baluns of small size and low cost. A metasurface based wide-angle impedance matching (MSWAIM) layer is introduced to replace the traditional dielectric WAIM, improving the beam scan performance and reducing the antenna profile. The simulation shows that the proposed antenna array can operate over 2.4-12.4 GHz, approximately 5:1 bandwidth with maximum scanning angle of 50o for both E plane and 45o for H plane. The antenna profile above the ground is only 0.578λH at the highest operating frequency. This antenna array can find its application in the forthcoming massive MIMO beamforming systems for 5G.

scholarly journals Microwave absorption and mechanical properties of double-layer cement-based composites containing different replacement levels of fly ash

2018 ◽  
Vol 25 (4) ◽  
pp. 707-714 ◽  
Author(s):  
Yuefang Zhang ◽  
Shunhua Liu ◽  
wanJun Hao
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Double Layer ◽  
Impedance Matching ◽  
X Ray Diffraction ◽  
Replacement Ratio ◽  
Matching Layer ◽  
Optimal Replacement ◽  
Zn Ferrite ◽  
Absorbing Layer

Abstract Double-layer absorbing cement-based composites with the thickness of 10 mm were prepared, including different replacement levels of fly ash (FA) in the absorbing layer as well as the matching layer for impedance matching. Waste polyethylene terephthalate bottle fragment was introduced as electromagnetic transparent reinforcement aggregate. Carbon black was used to be original absorbent in the absorbing layer. The microstructure and electromagnetic parameters of FA were closely looked at through scanning electron microscope, X-ray diffraction, and analyzer of vector network. The absorption and mechanical properties of cement-based composites were tested. It turned out that when the optimal replacement ratio of FA in the absorbing layer and matching layer gets to 50%:30%, the minimum value of reflection loss achieves −22.3 dB at 13.2 GHz; also, the value of absorption bandwidth that is effective (<−8 dB) is 6.4 GHz. Ni-Zn ferrite proves to be a feasible absorbent that is additional for the matching layer compared to what is added to the absorbing layer. The compressive strength of all the mixtures decreased, while the flexural strength decreased first and then increased with the rise of the FA replacement level.

Impedance Matching Design of a Low-Profile Wide-Angle Scanning Phased Array

2019 ◽  
Vol 67 (10) ◽  
pp. 6401-6409 ◽  
Author(s):  
Fu-Long Jin ◽  
Xiao Ding ◽  
You-Feng Cheng ◽  
Bing-Zhong Wang ◽  
Wei Shao
Keyword(s):  
Phased Array ◽  
Impedance Matching ◽  
Wide Angle ◽  
Low Profile ◽  
Matching Design

scholarly journals Design of Cavity-Backed Bow-Tie Antenna with Matching Layer for Human Body Application

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4015 ◽  
Author(s):  
Jeong ◽  
Park ◽  
Lee
Keyword(s):  
Reflection Coefficient ◽  
Human Body ◽  
Electromagnetic Interference ◽  
Impedance Matching ◽  
Human Head ◽  
Impedance Match ◽  
Broadband Antenna ◽  
Matching Layer ◽  
Antenna Performance ◽  
Bow Tie

This paper presents the broadband antenna for the microwave radiometric sensing of internal body temperature. For broadband operation, the bow-tie antenna was designed and backed with a cylindrical cavity, which decreased environmental electromagnetic interference and also improved the directivity of the antenna. The broadband impedance-transforming balun in microstrip form was also designed to feed the bow-tie antenna, and was located inside the cavity. An impedance-matching dielectric layer (IMDL) was introduced on top of the bow-tie antenna, for impedance match with the human body with high permittivity. The fabricated antenna was measured in free space with the IMDL removed, showing an input reflection coefficient lower than −10 dB from 2.64 to > 3.60 GHz with antenna gain over 6.0 dBi and radiation efficiency over 74.7% from 2.7 to 3.5 GHz. The IMDL was re-installed on the cavity-backed bow-tie antenna to measure the antenna performance for the human head with relative permittivity of about 40. The measured reflection coefficient was as low as −28.9 dB at 2.95 GHz and lower than −10 dB from 2.65 to > 3.5 GHz. It was also shown that the designed antenna recovered a good impedance match by adjusting the permittivity and thickness of the IMDL for the different parts of the human body with different permittivities.

A Wideband Phased Array With Broad Scanning Range and Wide-Angle Impedance Matching

2020 ◽  
Vol 68 (8) ◽  
pp. 6022-6031
Author(s):  
Fu-Long Jin ◽  
Xiao Ding ◽  
You-Feng Cheng ◽  
Bing-Zhong Wang ◽  
Wei Shao
Keyword(s):  
Phased Array ◽  
Impedance Matching ◽  
Wide Angle ◽  
Scanning Range
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