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Author

Ke Yanhui

Bio: Ke Yanhui is an academic researcher from Nantong University. The author has contributed to research in topics: Antenna (radio) & Dielectric resonator. The author has an hindex of 1, co-authored 7 publications receiving 3 citations.

Papers
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Journal ArticleDOI
TL;DR: By adding p-i-n diodes to the ends of the coupled quarter-wavelength lines, the proposed balun enables three-status operation while it has compact size and simple configuration.
Abstract: This letter proposes a microstrip switchable dual balun using a symmetrical three-coupled-line structure, which is used as a feeding network for designing a pattern-reconfigurable endfire antenna. By adding p-i-n diodes to the ends of the coupled quarter-wavelength lines, the proposed balun enables three-status operation while it has compact size and simple configuration. Based on this, a pattern-reconfigurable endfire antenna is designed, fabricated, and measured. Good agreement between the simulated and measured results can be observed. The peak gain of two directional statuses reaches 5.8 dBi and the front-to-back ratio (F/B) is more than 18 dB. Meanwhile, the peak gain of bidirectional status reaches 2.7 dBi and the F/B is less than 0.5 dB.

18 citations

Journal ArticleDOI
TL;DR: In this paper, a strip-loaded dielectric ring resonator (DRR) and near zero index (NZI) metamaterial (NZIM) was used to improve the in-band gain and enhance the filtering capability of a broadband filtering quasi-Yagi DRR antenna.
Abstract: This paper presents a design approach of broadband filtering quasi-Yagi DRR Antenna using a strip-loaded dielectric ring resonator (DRR) and near-zero-index (NZI) metamaterial (NZIM). The ring strip is loaded to the inside wall of the DRR so that the TE $_{01 \delta }$ and TE $_{21\delta }$ modes of the DRR can be close. Meanwhile, they function as a dual-mode magnetic dipole (M-dipole) driver and can be differentially excited at the same time for designing a wideband quasi-Yagi antenna. Benefiting from the dual-mode operation of the strip-loaded DRR, the end-fire gain across the operating band of the antenna is stable with preliminary bandpass filtering characteristics. To improve the in-band gain and enhance the filtering capability, a new coplanar NZIM with wideband NZI characteristic and dual transmission notches in the lower and upper stopbands of the preliminary gain passband, is introduced and put in the front of the DRR driver. To verify the proposed design concept, an X-band filtering quasi-Yagi antenna with the NZIM is fabricated and measured. Good agreement between the simulated and measured results can be observed. The wideband antenna has a measured −10 dB impedance bandwidth of about 16% (8.5 – 10 GHz). Within it, the peak gain of antenna reaches 8.3 dBi and 1-dB gain fractional bandwidth is about 10.8%. Meanwhile, it exhibits good gain bandpass response due to the transmission notches of the NZIM.

6 citations

Journal ArticleDOI
TL;DR: In this paper, a bidirectional dielectric resonator (DR) antenna array using back-to-back quasi-Yagi antenna configuration is proposed and implemented for the first time.
Abstract: A bidirectional dielectric resonator (DR) antenna array using back-to-back quasi-Yagi antenna configuration is proposed and implemented for the first time. The DR operating at higher-order TE3δ1 mode is used as a magnetic dipole, applying for the driver of quasi-Yagi antenna. Due to the high-order mode employment, the antenna gain can be enhanced. By partially loading the metallic strip on the side wall of the DR, the gain can be further enhanced. In addition, a simple dual Marchand balun is constructed for feeding the two quasi-Yagi antennas directly for bidirectional radiation. To verify the design concept, a prototype operating at the X-band is fabricated and measured. Good agreement between the simulated and measured results can be observed.

2 citations

Patent
24 Jan 2020
TL;DR: In this paper, a high-gain yagi antenna based on a dielectric resonator high-order mode and a metamaterial was proposed, and the antenna gain can reach 10.6dBi.
Abstract: The invention relates to a high-gain yagi antenna based on a dielectric resonator high-order mode and a metamaterial. The high-gain yagi antenna comprises a dielectric substrate, a reflector, a feed network, a driving unit and a metamaterial. The driving unit is a rectangular dielectric resonator working in a high-order mode. The meta-material formed by a plurality of mutually parallel long-strip-shaped metal strips is arranged on the upper surface of the dielectric substrate, and the long-strip-shaped metal strips are perpendicular to the driving unit. The feed network is a pair of feed micro-strip lines transitioned from a differential micro-strip line to a coplanar micro-strip line, and excites the dielectric resonator driving unit. Because of the application of the high-order mode TE3delta1 and the loading of the metamaterial, the antenna gain can reach 10.6dBi. The antenna gain can be improved by 2.3dBi by loading the metamaterial. The actual measurement result is well matched with the simulation result.

Cited by
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Journal ArticleDOI
TL;DR: In this paper , a symmetric split ring resonator (SRR) based metamaterial (MTM) is presented that exhibits three resonances of transmission coefficient (S21) covering S, C, and X-bands with epsilon negative (ENG) and near zero index properties.
Abstract: In this article, a symmetric split ring resonator (SRR) based metamaterial (MTM) is presented that exhibits three resonances of transmission coefficient (S21) covering S, C, and X-bands with epsilon negative (ENG) and near zero index properties. The proposed MTM is designed on an FR4 substrate with the copper resonator at one side formed with two square rings and one circular split ring. The two square rings are coupled together around the split gap of the outer ring, whereas two split semicircles are also coupled together near the split gaps. Thus, gap coupled symmetric SRR is formed, which helps to obtain resonances at 2.78 GHz, 7.7 GHz and 10.16 GHz with desired properties of the MTM unit cell. The MTM unit cell's symmetric nature helps reduce the mutual coupling effect among the array elements. Thus, different array of unit cells provides a similar response to the unit cell compared with numerical simulation performed in CST microwave studio and validated by measurement. The equivalent circuit is modelled for the proposed MTM unit cell in Advanced Design System (ADS) software, and circuit validation is accomplished by comparing S21 obtained in ADS with the same of CST. The effective medium ratio (EMR) of 10.7 indicates the compactness of the proposed MTM. A test antenna is designed to observe the effect of the MTM over it. Numerical analysis shows that the proposed MTM have an impact on the antenna when it is used as the superstrate and helps to increase the gain of the antenna by 95% with increased directivity. Thus, compact size, high EMR, negative permittivity, near zero permeability and refractive index makes this MTM suitable for S, C and X band applications, especially for antenna gain with directivity enhancement.

12 citations

Journal ArticleDOI
TL;DR: In this article , a pattern-reconfigurable dielectric resonator antenna (DRA) with compact structure and high efficiency is proposed by introducing a pair of switchable directors.
Abstract: A novel pattern-reconfigurable dielectric resonator antenna (DRA) with compact structure and high efficiency is proposed in this letter by introducing a pair of switchable directors. The switchable directors are arranged on both sides of an omnidirectional DRA, which operates in the TE01δ mode. Their directing function can be controlled by switching the on/off status of the p-i-n diodes so that one omnidirectional radiation pattern and two unidirectional endfire patterns are provided in the azimuthal plane. To verify this idea, a prototype of the proposed antenna is fabricated and measured. Good agreement between the simulated and measured results can be observed. The peak gain in endfire status reaches 4.5 dBi and the front-to-back ratio is more than 12 dB. Meanwhile, the gain variation of the omnidirectional pattern in the azimuth plane is less than 2 dB, which shows good omnidirectional radiation performance.

12 citations

Journal ArticleDOI
TL;DR: In this article , a novel pattern-reconfigurable dielectric resonator (DR) antenna with end-fire beam-scanning feature is proposed, which consists of a DR, a switchable director with 10 p-i-n diodes, and a differential feeding structure.
Abstract: A novel pattern-reconfigurable dielectric resonator (DR) antenna with endfire beam-scanning feature is proposed in this letter. The proposed antenna consists of a DR, a switchable director with 10 p-i-n diodes, and a differential feeding structure. The differential-fed DR operating in TE 01δ mode can provide a primary endfire pattern with wide beam. Based on this, a large-coverage beam-scanning performance can be obtained by introducing a switchable director placed in front of the DR. A prototype is fabricated and measured to verify the proposed design. By switching the p-i-n diodes of the switchable director, the proposed antenna enables a near-continuous beam scanning from −48° to +48° in the azimuth plane with a gain fluctuation of less than 0.5 dB. Besides, the 3 dB scanning coverage is up to 164° (from −82° to +82°), which shows good beam-scanning performance.

7 citations