Shi-Wei Qu

University of Electronic Science and Technology of China, Hua-yang, Sichuan, China

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Publications (47)71.07 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The active impedance of each element in a phased array changes substantially with scan angle due to mutual coupling. Therefore, a key challenge in the design of wide-angle scanning phased array is to achieve wide-angle impedance matching (WAIM). In this communication, an efficient decoupling network is developed to reduce the mutual coupling between adjacent elements for this purpose. A complete scattering matrix analysis of the decoupling network is given and the design procedure is summarized. A 1 × 16 linear microstrip phased array has been designed and fabricated for experimental verification. Good agreement is obtained between measured and simulated results. The measured mutual coupling between adjacent elements is reduced to lower than-35dB at the center frequency. Due to the reduced mutual coupling, the array can experimentally scan to 66° with a gain reduction of only 3.04 dB.
    IEEE Transactions on Antennas and Propagation 11/2015; 63(11):1-1. DOI:10.1109/TAP.2015.2476342 · 2.18 Impact Factor
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    ABSTRACT: In this communication, an H-plane sparse cavity-backed antenna array is proposed, and by using multiport elements, the number of array control components such as transmitting/receiving modules, phase shifters, and power dividers is reduced, and therefore cost of the phased array is saved. In the array, each subarray consists of an active and a passive element, and the active element not only works as an antenna but also as a power divider to feed the passive one. A reflection-type phase shifter (RTPS) is designed and integrated between the two elements, whose phase shift is controlled by two reflective loads. The distance between the neighboring active elements is ( is the free-space wavelength at the center of the operating frequency band), twice of that between the active and the passive elements. Meanwhile, cavity-backed structure is adopted to obtain unidirectional radiation patterns with high aperture efficiency. The proposed array can be used in both wide-angle scanning and limited field-of-view applications. Simulated and measured results are given and discussed to validate the proposed idea.
    IEEE Transactions on Antennas and Propagation 09/2015; 63(9):4175-4179. DOI:10.1109/TAP.2015.2444433 · 2.18 Impact Factor
  • Source
    Shi-Wei Qu · Wei-Wei Wu · Bao-Jie Chen · Huan Yi · Xue Bai · Kung Bo Ng · Chi Hou Chan ·
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    ABSTRACT: Terahertz (THz) metasurfaces have been explored recently due to their properties such as low material loss and ease of fabrication compared to three-dimensional (3D) metamaterials. Although the dispersion properties of the reflection/transmission-type THz metasurface were observed in some published literature, the method to control them at will has been scarcely reported to the best of our knowledge. In this context, flexible dispersion control of the THz metasurface will lead to great opportunities toward unprecedented THz devices. As an example, a THz metasurface with controllable dispersion characteristics has been successfully demonstrated in this article, and the incident waves at different frequencies from a source in front of the metasurface can be projected into different desired anomalous angular positions. Furthermore, this work provides a potential approach to other kinds of novel THz devices that need controllable metasurface dispersion properties.
    Scientific Reports 03/2015; 5:9367. DOI:10.1038/srep09367 · 5.58 Impact Factor
  • Qi Jiang · Shi-Wei Qu ·
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    ABSTRACT: In this letter, a novel three-element linear cavity- backed antenna (CBA) array with high aperture efficiency is proposed. First, in order to reduce the loss and cost caused by the feeding network, a multiport CBA acting as a radiator as well as a power divider is investigated. Then, based on the multiport CBA, a three-element antenna array with a wide operating frequency band (19–21 GHz) is designed. The simulated broadside gain is from 9.7 to 11.1 dBi over the whole operating band, and the aperture efficiency of the proposed CBA array ranges from 99.1% to 123.7%. The proposed idea has potential applications in low-cost antenna arrays due to the simplified feeding network.
    IEEE Antennas and Wireless Propagation Letters 01/2015; 14:1-1. DOI:10.1109/LAWP.2015.2410033 · 1.58 Impact Factor
  • Jixin Guo · Shiwen Yang · Shi-wei Qu · Jun Hu · Zaiping Nie ·

    IEEE Transactions on Antennas and Propagation 01/2015; DOI:10.1109/TAP.2015.2493559 · 2.18 Impact Factor
  • Xue Bai · Shi-Wei Qu · Huan Yi ·
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    ABSTRACT: Spoof planar plasmonic waveguides (SPPWs) show potential applications in many microwave and terahertz systems, e.g. imaging, communication and sensing, due to their capability of highly confining spoof surface plasmon polaritons (SPPs) and relatively low propagation loss. Meanwhile, efficient electromagnetic emission from the SPPWs is one of the dominant factors in the practical applications. In this article, we demonstrate a beam-scanning circularly polarized (CP) antenna based on the SPPW of blind-hole array, which can efficiently convert spoof SPPs propagating in the SPPW into free-space emissions. Several centre-inclined rectangular patches are adopted to achieve the CP emission. The antenna array was designed and fabricated in the microwave frequency band, and the measured results validate the good emission performance of the proposed array, e.g. high gain and wide-scan angle. Finally, the proposed idea can be further extended into the terahertz frequency band.
    Journal of Physics D Applied Physics 07/2014; 47(32):325101. DOI:10.1088/0022-3727/47/32/325101 · 2.72 Impact Factor
  • Source
    Shi-Wei Qu · Qing-Yong Chen · Ming-Yao Xia · Xiu Yin Zhang ·
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    ABSTRACT: This paper presents two kinds of novel elements to design single-layer dual-band reflectarray, with identical polarization in two closely separated bands. Several degrees of freedom of the proposed elements are tuned to match the desired phase compensations at two center frequencies simultaneously. It is noted that the dual-band characteristics are realized by a single integrated element rather than conventional dual-band elements with independent tunable components corresponding to two center frequencies. A 10 × 10-element offset-fed reflectarray operating at 9 and 13.5 GHz, with a ratio of the center frequencies 1.5, is designed and fabricated to validate the performance of the element, and the measured results show reasonable agreements with simulations. Due to the incompleteness of reflection phase distribution at the two center frequencies of the presented element, a complementary element with four resonances is introduced. Then, a 20 × 20-element reflectarray composed of both kinds of elements is also designed, and the measured results demonstrate a good availability of the proposed elements.
    IEEE Transactions on Antennas and Propagation 01/2014; 62(1):199-205. DOI:10.1109/TAP.2013.2287517 · 2.18 Impact Factor
  • Run-Liang Xia · Shi-Wei Qu · Qi Jiang · Peng-Fa Li · Zaiping Nie ·
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    ABSTRACT: An efficient decoupling feeding network is proposed in this letter. It is composed of two directional couplers and two sections of transmission line for connection use. By connecting the two couplers, an indirect coupling with controlled magnitude and phase is introduced, which can be used to cancel out the direct coupling caused by space waves and surface waves between array elements. To demonstrate the method, a two-element microstrip antenna array with the proposed network has been designed, fabricated and measured. Both simulated and measured results have simultaneously proved that the proposed method presents excellent decoupling performance. The measured mutual coupling can be reduced to below $-58 ~hbox{dB}$ at center frequency. Meanwhile it has little influence on return loss and radiation patterns. The decoupling mechanism is simple and straightforward which can be easily applied in phased array antennas and MIMO systems.
    IEEE Antennas and Wireless Propagation Letters 01/2014; 14:1-1. DOI:10.1109/LAWP.2014.2380786 · 1.58 Impact Factor
  • Huan Yi · Shi-Wei Qu · Xue Bai ·
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    ABSTRACT: This letter presents an efficient and simple way to excite a microstrip patch antenna array in K-band. This array is formed by a spoof planar plasmonic waveguide for excitation and several circular patches for radiation. The optimized proposed 2 × 4 patch array, operating in 18.1 ~ 19.4 GHz, features an average gain of 15.2 dBi with a maximum of 16.5 dBi at 18.2 GHz. An experiment was performed, and the measured results prove validity of the design. This method opens up a new kind of feeding method for patch antenna array, which can be broadly engineered in millimeter-waves (MMW) region even to terahertz (THz) region.
    IEEE Antennas and Wireless Propagation Letters 01/2014; 13:1227-1230. DOI:10.1109/LAWP.2014.2332257 · 1.58 Impact Factor
  • Source
    Shi-Wei Qu · Zai-Ping Nie ·
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    ABSTRACT: Future plasmonic integrated circuits with the capability of extremely high-speed data processing at optical frequencies will be dominated by the efficient optical emission (excitation) from (of) plasmonic waveguides. Towards this goal, plasmonic nanoantennas, currently a hot topic in the field of plasmonics, have potential to bridge the mismatch between the wave vector of free-space photonics and that of the guided plasmonics. To manipulate light at will, plasmonic nanoantenna arrays will definitely be more efficient than isolated nanoantennas. In this article, the concepts of microwave antenna arrays are applied to efficiently convert plasmonic waves in the plasmonic waveguides into free-space optical waves or vice versa. The proposed plasmonic nanoantenna array, with nanopatch antennas and a coupled wedge plasmon waveguide, can also act as an efficient spectrometer to project different wavelengths into different directions, or as a spatial filter to absorb a specific wavelength at a specified incident angle.
    Scientific Reports 11/2013; 3:3172. DOI:10.1038/srep03172 · 5.58 Impact Factor
  • Shi-Wei Qu · Ke-Bin Zhu · Zai-Ping Nie · Xiang-Yang Sun · Peng Yang ·
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    ABSTRACT: Effective downhole-to-surface transmission of the logging signals is one of the critical techniques for logging while drilling (LWD). This letter aims to evaluate an advanced scheme of signal transmission for the LWD proposed by Novatek, with an emphasis on the electromagnetic (EM) coupling between two adjacent pipes and the impedance matching between the coupler and the coaxial cables imbedded in drilling pipes. The numerical modeling of the EM coupling structure has been made by first using the full-wave simulation tool, and then the influence of the parameters of the coupler on the coupling coefficient has been discussed based on circuit simulation software. The optimization of the critical parameters has been made based on the given analysis. It has been found from the analysis that the air gap between the upper and the lower ferrite cores in the coupler is a key factor with remarkable influences on the impedance matching and the coupling coefficient.
    IEEE Geoscience and Remote Sensing Letters 09/2013; 10(5):1001-1005. DOI:10.1109/LGRS.2012.2227928 · 2.10 Impact Factor
  • Shi-Wei Qu · Xue Bai ·
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    ABSTRACT: This communication presents a novel and simple circularly polarized (CP) antenna constructed by an elliptical cavity and a dipole exciter for 60 GHz wireless personal area network (WPAN) applications. The simulated 3-dB axial ratio (AR) bandwidth is 27.1%, from 51 to 67 GHz, in which the standing-wave ratio (SWR) is kept below 2. Meanwhile, the broadside gain is varied from 5 to 10 dBi.
    2013 IEEE International Workshop on Electromagnetics; Applications and Student Innovation (iWEM); 08/2013
  • Xue Bai · Shi-Wei Qu ·
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    ABSTRACT: A cavity-backed crossed dipoles for circularly polarized (CP) radiation is presented. To improve the 3-dB axial ratio (AR) beamwidth and the broadside gain, a tapered elliptical cavity is introduced. The proposed antenna uses substrate integrated waveguide (SIW) as its feeder. The crossed dipoles is coupled-fed by a transverse slot on the top metallic surface of the SIW. Simulations show that the antenna can present a bandwidth from 56.1 to 62.5 GHz for a reflection coefficient S11 ≤ -10 dB as well as for an axial ratio (AR) =≤3 dB, and a high broadside gain of around 10.4 dBi on average is achieved. Meanwhile, the wide 3-dB AR beamwidth on all azimuth planes can be achieved. This design yields good directional radiation patterns and low fabrication cost.
    Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC), 2013; 07/2013
  • Shi-Wei Qu · Kung Bo Ng · Chi Hou Chan ·
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    ABSTRACT: A broadband millimeter-wave short backfire antenna (SBA), excited by a bowtie dipole and fed by an E-band rectangular waveguide, is presented in this paper. Its subreflector is replaced by two simple strips printed on the opposite sides of the same supporting substrate of the bowtie exciter for ease and accuracy of fabrication. For reference of practical designs, detailed parametric studies are performed in this paper. Measurements and simulations show that the proposed antenna can feature an improved operating bandwidth and broadside gain compared to the previously reported conventional SBAs. The measured impedance bandwidth for SWR ≤2 is 57%, from 55.7 to 100 GHz, in which the measured broadside gain is from 13.8 to 18.5 dBi with the peak gain at 85 GHz. Finally, high illumination efficiency of the bowtie exciter is highlighted by comparisons with a straight dipole excited SBA.
    IEEE Transactions on Antennas and Propagation 04/2013; 61(4):1697-1703. DOI:10.1109/TAP.2012.2232267 · 2.18 Impact Factor
  • Xue Bai · Shi-Wei Qu · Kung Bo Ng ·
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    ABSTRACT: A novel millimeter-wave antenna for circularly polarized (CP) radiation is presented. The proposed antenna is composed of a patch dipole and a slot dipole, and it is realized by a plated through-hole printed technique on a microwave substrate. Measurements show that the antenna can present a bandwidth from 56.2 to 65 GHz for a reflection coefficient S11 ≤ -10 dB as well as for an axial ratio (AR) ≤ 3 dB, and the 10.03-dBi average gain is achieved. This design yields good directional radiation patterns. Studies on several critical parameters are performed for practical designs.
    IEEE Antennas and Wireless Propagation Letters 01/2013; 12:1355-1358. DOI:10.1109/LAWP.2013.2286196 · 1.58 Impact Factor
  • Huan Yi · Shi-Wei Qu ·
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    ABSTRACT: In this letter, a dual-band polarization-dependent electromagnetic band-gap (PDEBG) surface is designed as a reflector of a dual-band dipole antenna to realize dual-band circular polarization. Experimental and numerical results verify the concept of the low-profile dual-band circularly polarized antenna. The antenna features 10-dB return-loss bandwidths of 13.4% and 3.2% and 3-dB axial-ratio bandwidths of 2.4% and 3.5% in low and high frequency bands, respectively. The proposed antenna can present the same or different circular polarization in two bands based on different designs of the PDEBG.
    IEEE Antennas and Wireless Propagation Letters 01/2013; 12:1149-1152. DOI:10.1109/LAWP.2013.2281060 · 1.58 Impact Factor
  • Xue Bai · Shi-Wei Qu ·
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    ABSTRACT: An implementation of circularly polarized crossed dipoles in millimeter-wave band is presented in this paper. Novel detached crossed dipoles have been designed to tackle the problems confronted by single-fed crossed dipoles in mm-wave band. An evolution procedure from conventional crossed dipoles to the proposed ones is given. Meanwhile, a metallic ridge is added in the cavity to provide a robust feeding structure. Measurements of an optimized antenna prototype show that it can achieve a bandwidth from 27 to 36.8 GHz for both AR ≤ 3 dB and |S11| ≤ -10 dB and an average broadside gain of 12.4 dBi. The measured results agree reasonably well with simulations. For reference to practical designs, studies on five critical parameters have also been performed in this paper.
    Progress In Electromagnetics Research Letters 01/2013; 36(12):133-142. DOI:10.2528/PIERL12101908
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    ABSTRACT: A novel single-layer reflectarray element with an I-shaped dipole encompassed by a circular ring, showing smooth phase-frequency response, is proposed in this letter. Based on this element, an optimization method is adopted to match the desired phase delays at two edge frequencies so as to get fixed phase difference between two adjacent elements in the optimized band. A low-profile X-band 6$,times,$10-element reflectarray with a scattering angle of 30$^{circ}$ for normal incidence of plane waves is designed and fabricated. Simulations and measurements show that a bandwidth of 22.3% for 3 dB directivity dropping and 15.2% for ${-}$10 dB sidelobe level (SLL) can be achieved.
    IEEE Antennas and Wireless Propagation Letters 01/2013; 12:317-320. DOI:10.1109/LAWP.2013.2249652 · 1.58 Impact Factor
  • Source
    Shi-Wei Qu · Kung Bo Ng ·
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    ABSTRACT: Although many directive antennas operating in a narrow band of millimeter (mm) waves were reported, e.g., antennas for 60-GHz wireless local area network (WLAN), their wideband counterparts are still unpopular. Cavity-backed antennas (CBAs) are widely developed and reported in microwave frequency bands, but handful of literatures can be found about mm-wave CBAs in spite that their many properties are quite suitable for mm-wave applications. This paper presents a wideband unidirectional CBA with a bowtie exciter, operating in a frequency band of 40 similar to over 75 GHz, and it is carefully analyzed in terms of influences of all components on the radiation patterns, broadside gains, and reflection coefficients of the proposed antenna. Then, the antenna prototype is built by generic printed circuit board (PCB) technologies, and measurements prove the validity of simulations.
    Progress In Electromagnetics Research 01/2013; 133:477-493. DOI:10.2528/PIER12091202 · 1.23 Impact Factor
  • Shi-Wei Qu · Kung Bo Ng ·
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    ABSTRACT: A broadband millimeter-wave cavity-backed antenna, excited by a rounded bowtie dipole, is reported in this letter. To improve the radiation patterns and the broadside gains, its aperture is optimized by cutting the sections with higher-order modes at lower frequencies away from a large aperture, forming a specific open cavity structure. Simulations show that the antenna can present an impedance bandwidth from 28 to over 50 GHz for ${\rm SWR} \leq 2$, and a bandwidth from 28 to 49 GHz for ${-}$ 10-dB sidelobe level. Measurements agree reasonably well with simulations. Comparisons between the antennas with and without the improved aperture in terms of electric field distribution and radiation patterns clearly show performance enhancement.
    IEEE Antennas and Wireless Propagation Letters 12/2012; 11:697-700. DOI:10.1109/LAWP.2012.2204719 · 1.58 Impact Factor

Publication Stats

251 Citations
71.07 Total Impact Points


  • 2011-2015
    • University of Electronic Science and Technology of China
      • School of Electronic Engineering
      Hua-yang, Sichuan, China
  • 2008-2015
    • The University of Hong Kong
      • Department of Electrical and Electronic Engineering
      Hong Kong, Hong Kong
  • 2010
    • Tohoku University
      • School of Engineering
      Sendai-shi, Miyagi-ken, Japan
  • 2007-2010
    • City University of Hong Kong
      • • State Key Laboratory of Millimeter Waves
      • • Department of Electronic Engineering
      Chiu-lung, Kowloon City, Hong Kong