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Jianying Li

Bio: Jianying Li is an academic researcher from Northwestern Polytechnical University. The author has contributed to research in topics: Antenna (radio) & Microstrip antenna. The author has an hindex of 18, co-authored 98 publications receiving 1106 citations. Previous affiliations of Jianying Li include Northwestern Polytechnic University.

Papers published on a yearly basis

Papers
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Journal ArticleDOI
Kun Wei1, Jianying Li1, Ling Wang1, Zijian Xing1, Rui Xu1 
TL;DR: In this paper, a fractal defected ground structure (FDGS) is proposed to reduce mutual coupling between coplanar spaced microstrip antenna elements, and the structure of the proposed FDGS is studied.
Abstract: This paper presents a novel fractal defected ground structure (FDGS) to reduce mutual coupling between coplanar spaced microstrip antenna elements. The structure of the proposed FDGS is studied. Bandgap characteristic of second and third iterative FDGS is achieved. The second and third iterative FDGSs are used to reduce mutual coupling between microstrip antenna elements. Mutual coupling reduction performance of third iterative FDGS is better than that of second iterative FDGS. And dimension of FDGS can be decreased by using higher level iterative FDGS. The third iterative FDGS is fabricated and measured. Simulated and measured results both show that more than 35-dB mutual coupling reduction is obtained by using the third iterative FDGS. Moreover, the envelope correlation of antenna elements with FDGS is quite smaller than that of antenna elements without FDGS.

176 citations

Journal ArticleDOI
Kun Wei, Jianying Li, Ling Wang, Zijian Xing, Rui Xu 
TL;DR: In this paper, a novel S-shaped periodic defected ground structure (PDGS) is proposed to reduce mutual coupling between antenna elements, which achieves more than 40 dB mutual coupling reduction between microstrip antenna elements.
Abstract: A novel S-shaped periodic defected ground structure (PDGS) is proposed to reduce mutual coupling between antenna elements. Coplanar placed antenna elements work at the same frequency band with centre frequency 2.57 GHz. Centre-to-centre distance between the antenna elements is 50 mm which is ~0.43λ. The PDGS is three S-shaped defected ground structure units placed between microstrip antenna elements. By using the proposed PDGS, more than 40 dB mutual coupling reduction between microstrip antenna elements is achieved.

112 citations

Journal ArticleDOI
Kun Wei1, Jianying Li1, Lei Wang1, Rui Xu1, Zijian Xing1 
TL;DR: In this article, a new technique to design single-feed circularly polarized (CP) microstrip antenna is proposed, which is obtained by adjusting the dimension of the etched fractal defected ground structure (FDGS) in the ground plane.
Abstract: A new technique to design single-feed circularly polarized (CP) microstrip antenna is proposed. The CP radiation is obtained by adjusting the dimension of the etched fractal defected ground structure (FDGS) in the ground plane. Parameter studies of the FDGS are given to illustrate the way to achieve CP radiation. The CP microstrip antennas with the second and third iterative FDGS are fabricated and measured. The measured 10-dB return-loss bandwidth of the CP microstrip antenna is about 30 MHz (1.558 to 1.588 GHz), while its 3-dB axial-ratio bandwidth is 6 MHz (1.572 to 1.578 GHz). The gain across the CP band is between 1.7 and 2.2 dBic.

103 citations

Journal ArticleDOI
TL;DR: In this paper, a dual circularly polarized (CP) antenna with an U-shaped slot and two 50-Omega $ microstrip-fed ports was proposed to realize both right-hand circular polarization and left-hand polarization at the same frequency band.
Abstract: In this communication, a novel broadband dual circularly polarized (CP) antenna is presented. This antenna consists of an U-shaped slot to achieve broadband CP radiation and two 50- $\Omega $ microstrip-fed ports to realize both right-hand circular polarization and left-hand circular polarization at the same frequency band. The axial ratio bandwidth (ARBW) is greatly broadened by moving the feeding ports to upper portion of the U-shaped slot. To verify this design, the proposed antenna is fabricated and measured. The measured −10 dB reflection coefficient bandwidth is about 114.4% (1.80–6.61 GHz) and the 3-dB ARBW is approximately 110.5% (1.83–6.35 GHz). The isolation between two ports is better than 14.8 dB within the ARBW.

81 citations

Journal ArticleDOI
TL;DR: In this article, a wide-beam microstrip antenna with metal walls is proposed to improve the wide-angle scanning performance of the phased array antennas, and the beamwidth of the antenna is broadened by the horizontal current on the radiating patch and the vertical currents on the metal walls.
Abstract: In order to improve the wide-angle scanning performance of the phased array antennas, a wide-beam microstrip antenna with metal walls is proposed in this letter. The beamwidth of the antenna is broadened by the horizontal current on the radiating patch and the vertical current on the metal walls. The half-power beamwidth of the E- and H-planes is 221° and 168° at 4.0 GHz. Furthermore, the wide-beam antenna element is employed in a nine-element E-plane linear array antenna. The main beam of the E-plane scanning linear array antenna can scan from −70° to +70° in the frequency band from 3.7 to 4.3 GHz with a gain fluctuation less than 2.7 dB and variation in maximum sidelobe level less than −5.8 dB. The E-plane scanning linear array antenna with nine elements is fabricated and tested. The measured results achieve a good agreement with the simulated results.

78 citations


Cited by
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01 Jan 2016

733 citations

Journal ArticleDOI
TL;DR: It is shown that the mutual-coupling reduction methods inspired by MTM and MTS concepts can provide a higher level of isolation between neighbouring radiating elements using easily realizable and cost-effective decoupling configurations that have negligible consequence on the array’s characteristics such as bandwidth, gain and radiation efficiency, and physical footprint.
Abstract: Nowadays synthetic aperture radar (SAR) and multiple-input-multiple-output (MIMO) antenna systems with the capability to radiate waves in more than one pattern and polarization are playing a key role in modern telecommunication and radar systems. This is possible with the use of antenna arrays as they offer advantages of high gain and beamforming capability, which can be utilized for controlling radiation pattern for electromagnetic (EM) interference immunity in wireless systems. However, with the growing demand for compact array antennas, the physical footprint of the arrays needs to be smaller and the consequent of this is severe degradation in the performance of the array resulting from strong mutual-coupling and crosstalk effects between adjacent radiating elements. This review presents a detailed systematic and theoretical study of various mutual-coupling suppression (decoupling) techniques with a strong focus on metamaterial (MTM) and metasurface (MTS) approaches. While the performance of systems employing antenna arrays can be enhanced by calibrating out the interferences digitally, however it is more efficient to apply decoupling techniques at the antenna itself. Previously various simple and cost-effective approaches have been demonstrated to effectively suppress unwanted mutual-coupling in arrays. Such techniques include the use of defected ground structure (DGS), parasitic or slot element, dielectric resonator antenna (DRA), complementary split-ring resonators (CSRR), decoupling networks, P.I.N or varactor diodes, electromagnetic bandgap (EBG) structures, etc. In this review, it is shown that the mutual-coupling reduction methods inspired By MTM and MTS concepts can provide a higher level of isolation between neighbouring radiating elements using easily realizable and cost-effective decoupling configurations that have negligible consequence on the array’s characteristics such as bandwidth, gain and radiation efficiency, and physical footprint.

226 citations

Journal ArticleDOI
TL;DR: Different MIMO antenna design techniques and all of their mutual coupling reduction techniques through various structures and mechanisms are presented with multiple examples and characteristics comparison.
Abstract: In recent years, multiple-input-multiple-output (MIMO) antennas with the ability to radiate waves in more than one pattern and polarization play a great role in modern telecommunication systems. This paper provides a theoretical review of different mutual coupling reduction techniques in MIMO antenna systems. The increase in the mutual coupling can affect the antenna characteristics drastically and therefore degrades the performance of the MIMO systems. It is possible to improve the performance partially by calibrating the mutual coupling in the digital domain. However, the simple and effective approach is to use the techniques, such as defected ground structure, parasitic or slot element, complementary split ring resonator, and decoupling networks which can overcome the mutual coupling effects by means of physical implementation. An extensive discussion on the basis of different mutual coupling reduction techniques, their examples, and comparative study is still rare in the literature. Therefore, in this paper, different MIMO antenna design techniques and all of their mutual coupling reduction techniques through various structures and mechanisms are presented with multiple examples and characteristics comparison.

197 citations

Journal ArticleDOI
TL;DR: In this article, an active metasurface composed of butterfly-shaped unit cells embedded with voltage-controlled varactor diodes was proposed to adaptively switch among linear-to-linear, linear to linear, linearto-elliptical, and linear to circular polarization conversions in a wideband.
Abstract: We propose an active metasurface whose functionalities can be dynamically switched among linear-to-linear, linear-to-elliptical, and linear-to-circular polarization conversions in a wideband. The active metasurface is composed of butterfly-shaped unit cells embedded with voltage-controlled varactor diodes. By controlling the bias voltage of the varactor diodes, the electromagnetic responses of the proposed metasurface can be tailored, leading to reconfigurable polarization conversions. The simulation results reveal that with no bias voltage, the proposed metasurface is able to reflect linear-polarization waves to cross-polarization waves in the frequency range from 3.9 to 7.9 GHz, with a polarization conversion ratio of over 80%; however, at the bias voltage of −19 V, the metasurface is tuned to be a circular polarization converter in a wideband from 4.9 to 8.2 GHz. Moreover, two equivalent circuits along the $x$ - and $y$ -directions are developed to elucidate the tunable mechanism. The experimental results are in a good agreement with the simulation results obtained from commercial software and from the equivalent circuit model.

151 citations