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Author

Yan-Yuan Zhu

Bio: Yan-Yuan Zhu is an academic researcher from Nanjing University of Science and Technology. The author has contributed to research in topics: Antenna (radio) & Wideband. The author has co-authored 3 publications.

Papers
More filters
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

Proceedings ArticleDOI
19 May 2019
TL;DR: In this paper, a low-loss balanced bandpass filter (BPF) based on half-wavelength dielectric strip resonator is proposed, which consists of a thin dielectrics strip with high permittivity and a lowpermittivity substrate with bottom ground plane.
Abstract: In this paper, a low-loss balanced bandpass filter (BPF) based on half-wavelength dielectric strip resonator is proposed, which consists of a thin dielectric strip with high permittivity and a low-permittivity substrate with bottom ground plane. The dielectric strip is used to replace the metal strip of the traditional microstrip line. Since there is no induced surface current on the dielectric strip, the unloaded quality factor (Qu) of the proposed resonator can be improved significantly, especially at high frequency. Meanwhile, the proposed resonator can be easily excited by the differential tapped microstrip lines for constructing the balanced BPF because its odd symmetric E-field distribution is similar to the microstrip counterpart. A prototype of the balanced BPF is simulated to show the advantages of the dielectric strip resonator.

Cited by
More filters
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 wideband filtering dielectric resonator antenna (DRA) based on the HEM11δ mode is proposed with high roll-off rate and flat gain response in the whole passband.
Abstract: In this letter, a wideband filtering dielectric resonator antenna (DRA) based on the HEM11δ mode is proposed with high roll-off rate and flat gain response in the whole passband. The proposed filtering DRA is excited by a simple feed structure composed of a driven ring, a parasitic ring and a driven arc. Each of them can excite the HEM11δ mode at different resonant frequencies, thus enlarging the impedance bandwidth of the proposed filtering DRA. Since the three resonant frequencies belong to the same mode, stable radiation pattern can be achieved simultaneously. In addition, two radiation nulls are generated near the lower and upper edges of the passband by the feed structure, making the proposed DRA obtain high frequency selectivity. All the three resonant frequencies and two radiation nulls are independently adjustable. A prototype has been fabricated and measured for demonstration, and the measured results are coincided with the simulated ones.

2 citations

Journal ArticleDOI
01 May 2023-Sensors
TL;DR: In this article , a Yagi-Uda antenna with stable gain by near-zero-index metamaterial (NZIM) has been proposed for vehicular 5G communication, which consists of magneto-electric dipole structure and coaxial feed patch antenna.
Abstract: In this paper, a stereoscopic ultra-wideband (UWB) Yagi–Uda (SUY) antenna with stable gain by near-zero-index metamaterial (NZIM) has been proposed for vehicular 5G communication. The proposed antenna consists of magneto-electric (ME) dipole structure and coaxial feed patch antenna. The combination of patch antenna and ME structure allows the proposed antenna can work as a Yagi–Uda antenna, which enhances its gain and bandwidth. NZIM removes a pair of C-notches on the surface of the ME structure to make it absorb energy, which results in two radiation nulls on both sides of the gain passband. At the same time, the bandwidth can be enhanced effectively. In order to further improve the stable gain, impedance matching is achieved by removing the patch diagonally; thus, it is able to tune the antenna gain of the suppression boundary and open the possibility to reach the most important characteristic: a very stable gain in a wide frequency range. The SUY antenna is fabricated and measured, which has a measured −10 dBi impedance bandwidth of approximately 40% (3.5–5.5 GHz). Within it, the peak gain of the antenna reaches 8.5 dBi, and the flat in-band gain has a ripple lower than 0.5 dBi.
Journal ArticleDOI
TL;DR: In this article , the authors proposed using a topological photonic crystal (TPC) as an effective feeding method, which can effectively suppress the reflecting loss at the feeder/DRA interface.
Abstract: Over the last 30 years, various dielectric resonator antennas (DRAs) have been developed for application in portable wireless communications and millimeter wave systems. However, current methods to feed the antennas suffer from radiation leakage and high losses. In this paper, we propose using a topological photonic crystal (TPC) as an effective feeding method, which can effectively suppress the reflecting loss at the feeder/DRA interface. As a demonstration, we numerically design a DRA with a TPC feeder, operating in a high-order resonant mode at 1.5 THz. Simulation results show that the antenna has a return loss as low as 44 dB, an impedance bandwidth of 3.9%, a maximum gain of 7.4 dBi, and 3dB angular widths of 58 degrees. Over 99% radiation efficiency can be achieved at the operating THz band. The proposed all-dielectric antenna can be suitably used for integrated photonic chips, biomedical applications, and 6G.