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Naizhi Wang

Bio: Naizhi Wang is an academic researcher from Northwestern Polytechnical University. The author has contributed to research in topics: Dielectric resonator antenna & Patch antenna. The author has an hindex of 5, co-authored 8 publications receiving 259 citations. Previous affiliations of Naizhi Wang include China Electronics Technology Group Corporation (China).

Papers
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Journal ArticleDOI
TL;DR: In this article, a Fabry-Perot (FP) resonator antenna with a wide gain bandwidth in the X band was proposed, which is attributed to the positive reflection phase gradient of an electromagnetic band gap (EBG) structure, constructed by the combination of two complementary frequency selective surfaces (FSSs).
Abstract: This paper presents a novel design of a Fabry-Perot (FP) resonator antenna with a wide gain bandwidth in X band. The bandwidth enhancement of the antenna is attributed to the positive reflection phase gradient of an electromagnetic band gap (EBG) structure, which is constructed by the combination of two complementary frequency selective surfaces (FSSs). To explain well the design procedure and approach, the EBG structure is modeled as an equivalent circuit and analyzed using the Smith Chart. Experimental results show that the antenna possesses a relative 3 dB gain bandwidth of 28%, from 8.6 GHz to 11.4 GHz, with a peak gain of 13.8 dBi. Moreover, the gain bandwidth can be well covered by the impedance bandwidth for the reflection coefficient ( ${\rm S} _{11}$ ) below $-10~{\rm dB}$ from 8.6 GHz to 11.2 GHz.

182 citations

Journal ArticleDOI
TL;DR: In this article, a double-layered dielectric superstrate, which produces a reflection phase curve versus frequency with a positive slope, is used as a partially reflective surface (PRS) to enhance the bandwidth of the Fabry-Perot resonator antenna.
Abstract: This letter presents a new design of a Fabry–Perot resonator antenna (FPRA) with a wide gain bandwidth. A double-layered dielectric superstrate, which produces a reflection phase curve versus frequency with a positive slope, is used as a partially reflective surface (PRS) to enhance the bandwidth of the FPRA. For a physical insight, the PRS is analyzed by using the transmission line theory and Smith Chart. Experimental results demonstrate that the antenna has a 3-dB gain bandwidth over 13.5–17.5 GHz, relatively 25.8%, with a peak gain of 15 dBi. Furthermore, the gain band is overlapped well by the impedance band for the reflection coefficient ( ${ S}_{11}$ ) less than $-$ 10 dB.

76 citations

Journal ArticleDOI
TL;DR: In this article, a partially re-ective surface (PRS) with positive re∞ection phase gradients is proposed for a wideband EBG resonator antenna operating at Ku band which is fed by a slot-coupled patch antenna.
Abstract: In this paper, we propose a method to use 1-D dielectric slabs, instead of metallic Frequency Selective Surfaces (FSSs), to produce Partially Re∞ective Surfaces (PRSs) with positive re∞ection phase gradients. The structure is realized by a single kind of dielectric substrate. It is modeled as cascaded transmission lines and then analyzed by virtue of the Smith Chart from the perspective of impedance transformation. A PRS designed by this approach is then applied to the realization of a wideband EBG resonator antenna operating at Ku band which is fed by a slot-coupled patch antenna. The calculated results indicate that the antenna possesses a relative 3dB gain bandwidth of 22%, from 14.1GHz to 17.6GHz, with a peak gain of 17dBi. The impedance bandwidth for the re∞ection coe-cient (S11) less than i10dB, is from 14GHz to 17.7GHz, well covering the 3dB gain bandwidth. A prototype has been fabricated and measured, and the experimental results well validate the simulation. The design method developed here is signiflcantly efiective, and can be easily adopted for antenna designs at other frequencies.

28 citations

Journal ArticleDOI
TL;DR: In this article, an integrated ultrawideband (UWB) and narrowband (NB) rectangular dielectric resonator antenna (DRA) was proposed for cognitive radio applications.
Abstract: An integrated ultrawideband (UWB) and narrowband (NB) rectangular dielectric resonator antenna (DRA) is presented. The proposed antenna consists of a UWB rectangular DRA excited by a bevel-shaped patch and an NB DRA excited by a strip. The measured results demonstrate that the UWB and NB antenna provides a 2:1 voltage standing wave ratio (VSWR) bandwidth for 2.4-12 and 2.3-4.5 GHz, respectively, with the same polarization. Moreover, two symmetrical short-circuited strips are introduced to improve the isolation between the two ports. This can be a suitable candidate for applications in cognitive radio, where the UWB antenna can be used for spectrum sensing and the NB antenna for communication operation.

23 citations

Journal ArticleDOI
TL;DR: In this paper, a frequency reconfigurable patch antenna using reed switches to connect the patch with the ground plane is proposed, which can operate in the frequency range from 0.3 to 3 GHz.
Abstract: A frequency reconfigurable patch antenna using reed switches to connect the patch with the ground plane is proposed. Compared with other voltage-controlled switches like MEMS and PIN diodes, reed switches are controlled by a magnetic field which can penetrate the ground plane easily. In this way, the control circuit can be placed beneath the ground plane to avoid its impacts on the radiation performance of the antenna. Twenty-four reed switches are used to increase the reconfigurability of the antenna and to show the feasibility of our concept when multiple control circuits are used simultaneously. The presented antenna can be reconfigured to operate in the frequency range from 0.3 to 3 GHz, covering for a large number of communication services. Three operating modes of the antenna (with resonance frequencies at 0.8, 2, and 2.85 GHz, respectively) are presented to illustrate the feasibility of this method. The measured matching and radiation characteristics of the fabricated antenna prototype agree well with the simulations.

12 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, a Fabry-Perot (FP) resonator antenna with a wide gain bandwidth in the X band was proposed, which is attributed to the positive reflection phase gradient of an electromagnetic band gap (EBG) structure, constructed by the combination of two complementary frequency selective surfaces (FSSs).
Abstract: This paper presents a novel design of a Fabry-Perot (FP) resonator antenna with a wide gain bandwidth in X band. The bandwidth enhancement of the antenna is attributed to the positive reflection phase gradient of an electromagnetic band gap (EBG) structure, which is constructed by the combination of two complementary frequency selective surfaces (FSSs). To explain well the design procedure and approach, the EBG structure is modeled as an equivalent circuit and analyzed using the Smith Chart. Experimental results show that the antenna possesses a relative 3 dB gain bandwidth of 28%, from 8.6 GHz to 11.4 GHz, with a peak gain of 13.8 dBi. Moreover, the gain bandwidth can be well covered by the impedance bandwidth for the reflection coefficient ( ${\rm S} _{11}$ ) below $-10~{\rm dB}$ from 8.6 GHz to 11.2 GHz.

182 citations

Journal ArticleDOI
TL;DR: In this paper, a chessboard arranged metamaterial superstrate (CAMS) is used to enhance the antenna gain and reduce the radar cross-section (RCS) of a Fabry-Perot (FP) resonator antenna.
Abstract: The simultaneous improvement in radiation and scattering performance of an antenna is normally considered as contradictory. In this paper, wideband gain enhancement and radar cross section (RCS) reduction of Fabry–Perot (FP) resonator antenna are both achieved by using chessboard arranged metamaterial superstrate (CAMS). The CAMS is formed by two kinds of frequency-selective surfaces. The upper surface of CAMS is designed to reduce RCS based on the phase cancellation principle, and the bottom surface is used to enhance antenna gain on the basis of FP resonator cavity theory. Both simulation and measured results indicate that compared with primary antenna, the gain of the proposed FP resonator antenna is enhanced by 4.9 dB at 10.8 GHz and the 3 dB gain bandwidth is from 9.4 to 11.1 GHz (16.58%). Meanwhile, the RCS of the proposed FP resonator antenna is reduced from 8 to 18 GHz, with peak reduction of 39.4 dB. The 10 dB RCS reduction is obtained almost from 9.6 to 16.9 GHz (55.09%) for arbitrary polarizations. Moreover, the in-band RCS is greatly reduced, owing to the combined effect of CAMS and FP resonator cavity.

137 citations

Journal ArticleDOI
TL;DR: A critical review of metasurfaces, which are planar metamaterials, can be found in this paper, where the authors discuss salient features and applications of metamurfaces; wavefront shaping; phase jumps; non-linear metasuranfaces; and their use as frequency selective surfaces (FSS).
Abstract: This paper is a critical review of metasurfaces, which are planar metamaterials. Metamaterials offer bespoke electromagnetic applications and novel properties which are not found in naturally occurring materials. However, owing to their 3D-nature and resonant characteristics, they suffer from manufacturing complexity, losses and are highly dispersive. The 2-dimensional nature of metasurfaces allows ease of fabrication and integration into devices. The phase discontinuity across the metasurface offers anomalous refraction, thereby conserving the good metamaterial properties while still offering the low-loss characteristics. The paper discusses salient features and applications of metasurfaces; wavefront shaping; phase jumps; non-linear metasurfaces; and their use as frequency selective surfaces (FSS).

136 citations

Journal ArticleDOI
TL;DR: In this paper, a single-slab superstrate that has a permittivity gradient in the directions transverse to the antenna axis was proposed for a single feed RCA with a measured 3-dB directivity bandwidth of 52.9% and 16.4-dBi.
Abstract: Extremely wideband resonant cavity antennas (RCAs) with large directivity-bandwidth products (DBPs) are presented. Their distinct feature is a single-slab superstrate that has a permittivity gradient in the directions transverse to the antenna axis. The application of such a superstrate in a single-feed RCA improves the DBP by a factor of three or more as compared with superstrates composed of uniform dielectric slabs. Their very small area enables an antenna designer to achieve unprecedented figures of DBP per unit area, from a simple planar antenna. Prototype RCAs have been fabricated and measurements have validated the concept. A measured 3-dB directivity bandwidth of 52.9% was demonstrated with a measured directivity of 16.4 dBi for an RCA that has a very small total footprint area of 1.54 $\lambda_0^2$ at the lowest operating frequency (2.84 $\lambda_{0,c}^2$ at the center frequency). This represents an increase of 90% over the previous best measured RCA directivity bandwidth of 28%.

100 citations

Journal ArticleDOI
TL;DR: In this paper, a shared-surface dual-band antenna using characteristic mode analysis (CMA) is proposed for 5G operation using a metasurface at the S$ -band and a partially reflective surface (PRS) at the Ka-band.
Abstract: A shared-surface dual-band antenna is proposed for 5G operation using characteristic mode analysis (CMA). The surface is the integration of a metasurface at the ${S}$ -band and a partially reflective surface (PRS) at the Ka -band. The resonant mode of the metasurface is excited by a microstrip-fed slot, and the PRS with a pair of substrate-integrated waveguide (SIW)-fed slots are employed to form a Fabry–Perot resonator antenna (FPRA). Measurements realized on a physical prototype of the antenna show a 10 dB impedance bandwidth of 23.45% and 9.76% and a realized gain that varies from 7.27 to 10.44 dBi and from 11.8 to 14.6 dBi, over the ${S}$ -band (3.2–4.05 GHz) and the Ka -band (26.8–29.55 GHz), respectively.

96 citations