Applied Electromagnetics Laboratory
Department of Electronic Engineering and Information Science
School of information Science & Technology
The University of Science and Technology of China
Staff:
Head:
Shanjia Xu, Professor
Main Research Members:
Yunsheng Xu, Professor
Qi Zhu, Associate Professor
Communication Address:
Mail Address:
Department of Electronic Engineering and Information Science
The University of Science and Technology of China
P.O. Box 4, Hefei, Anhui 230027 P.R. China
Tel: 86-551-3601321;
Fax: 86-551-3601355
E-mail Address:
Research Description and Interests:
The main research interests of the laboratory lie in the studies of electro-magnetic wave phenomena and applications in millimeter and optical wave engineering. Such as: wave propagation, scattering and radiation in various media; new numerical and analytical methods for analyzing the wave phenomena; new antenna and guiding structures for applications in electronic engineering.
The main research activities in recent years of this laboratory are as follows:
1. Nonuniform dielectric waveguide and its applications.
Open dielectric waveguides have become increasingly important in the areas of integrated optics and millimeter-wave integrated circuits. An integrated circuit may consist of various waveguiding components, which are usually interconnected by gradual transition waveguides, in order to reduce the scattering loss. Generally speaking the transition waveguides, such as a bend or curved waveguide, a taper or a junction, a transition or a coupling structure may be regarded as a nonuniform waveguide. The purpose of this investigation is to get new knowledge and better understanding for different nonuniform waveguides about the variety of phenomena associated with the leakage of guided energy and leakage-related resonate effects under appropriate circumstances and to quantify the scattering characteristics of various types of nonuniform waveguides as well as to suggest some useful guidelines for design of nonuniform dielectric structures in integrated circuits.
2. Omni-directional antennas and other new antennas for millimeter-wave Applications.
The millimeter-wave region is increasingly utilized for various systems. It has generated a need for developing new types of antennas, including omni-directional antennas to suit the various constraints imposed by these systems. The purpose of this investigation is to create some new millimeter-wave omni-directional antenna and leaky wave antenna structures as well as to propose some effective analysis methods to calculate the performances of the new antennas.As a result, the new type antennas can be conveniently designed and manufactured to meet the practical requirements of different systems.
3. Dielectric periodic structure and its applications.
The great demand for wireless communication systems is pushing designers toward mobile communication systems within small-size transmission areas. That has spurred on a research for highly integrated, small and inexpensive components that can support this kind of infrastructure. Both in millimeter-wave and optic integrated circuits of such systems, the dielectric periodic structure has demonstrated its considerable value; and it has been widely used in filters, couplers and traveling wave antennas. The purpose of this investigation is to develop an accurate but simple approach to analyze the scattering and radiation characteristics of the dielectric periodic structures so that the design procedure of the related elements in the circuits and systems becomes convenient and easy.
4. Engineerlized method for electromagnetic field problems.
Different kinds of guiding structures play an important role in advanced electrical and communication systems. The success of these systems depends strongly on the deep understanding of the propagation and scattering properties of the guiding structures. However, in practical case, often the structures have rather complicated geometry dimensions and dielectric distributions. Therefore, sometimes it could be very difficult to solve this problem with field method. The purpose of this investigation is to develop some engineerlized method such as modified multimode network method, improved perturbation method, generalized transverse resonance method, impedance transform technique and simplified mode-matching method etc., to solve the eigenvalue problems for different guiding structures so that the design procedure of the systems can be greatly simplified with getting twice the results with half the effort.
5. Design and analysis of beamforming network of communication satellite.
For frequency below X-band, a satellite beamforming network (BFN) using waveguide technology is not acceptable for space applications due to its heavy weight, volume and complexity. Recently, BFNs using rectangular coaxial line technology have been applied for the feed systems of C-band satellites. By using this technology, very compact, lightweight and low loss BFNs can be built. However, there is no analytical solution for the rectangular coaxial waveguide. The purpose of this investigation is to create a new approach for the scattering analysis of the rectangular coaxial line discontinuities and to provide effective and powerful CAD software for practical use in the BFN design. It is demonstrated theoretically and experimentally that the new approach has the generality of the finite element method and the simplicity of the multimode network method while retaining the high accuracy of the mode-matching method.
6. Edge-element method and its applications.
The functional formulation with full magnetic vector is widely used to rigorously evaluate propagation problems of different complicated guiding structures filled with isotropic or anisotropic materials. The most serious problem associate with this approach is the appearance of the spurious solutions. It is verified by some authors that the edge-element method is one of the most effective ways to eliminate the spurious solutions. However, comparison with the conventional finite element method, the edge-element method is not so mature and perfect either in mathematics or in the practice. The purpose of this investigation is to bring up the criterions for space construction of the edge-element and to propose new efficient high-order mixed edge-element structure as well as to establish smart division techniques for practical applications in computations of electromagnetic field problem.
7. Theoretical and experimental investigations on leaky wave mechanism and radiation characteristics of dielectric guiding structures
In this research the leaky wave characteristics of dielectric waveguides are theoreticallyand experimentally investigated; emphasis is lay on the study of the physical mechanism of the leaky wave phenomenon and the application and suppression of the leaky wave. Based on thoroughly understanding of the leaky mechanism and correctly control of the leakage, guidelines for designing of new and efficient leaky wave antennas are scientifically proposed. Also, different methods for suppressing the interferences between the integrated circuits caused by leaky effect are effectively developed. New leaky wave antennas that are the hybrid structure of NRD guide, groove guide and microstrip line are presented.
Current Research Projects:
The main research projects undertaking in the laboratory are as follows:
1. Theoretical and experimental investigations on leaky wave characteristics of dielectric guiding structures. (Supported by the National Natural Science Foundation of China and Foundation of Ministry of Science & Technology)
2. The investigation on radiation characteristics of the surface wave guiding structures. (Supported by the National Natural Science Foundation of China and Foundation of Education Ministry)
3. Optical grating and its applications. (Supported by the National Natural Science
Foundation of China)
3. Hall-Effect measurement of semiconductor with contact less microwave techniques. (Supported by the National Natural Science Foundation of China)
4. Theoretical and experimental investigation on the determination of semiconductor property parameters. (Supported by the State Education Commission)
5. The investigation on electromagnetic coupling between the patch/dipole and the transmission line and mutual coupling among the elements of microstrip array. (Supported by the National Defense Technique Council)
6. The investigation on radiation and EMC analysis for aircraft with many air borne antennas on it. (Supported by the National Defense Technique Council)
- Wavelet and its application in scattering and inverse scattering analysis.
(Supported by the National Defense Technique Council)
- Analysis and design of Active Integrated Antennas and microstrip antennas .
(Supported by the Ministry of Information Industry of China )
- Microwave passive and active devices analysis and design.
(Supported by the Ministry of Information Industry of China, and US Microsoft Cooperation )
10. Investigations on scattering and radiation characteristics of electrically large objects. (Supported by the Anhui Natural Science Foundation)
11. Design of new type phased antennas / arrays.
( Supported by National Defense Technique Council )
Biography:
Professor Shanjia Xu
Shanjia Xu was born in Zhejing, China on July 9, 1939. He graduated from the university of Science and Technology of China (USTC) in 1965. Since then he has been with the same university. He was promoted directly from Lecturer to Professor and became associate chairman of the Department in 1986. From 1994 to 1999 he was the vice-present of HighTechnicalCollege and from 1993 to 1999 he was the chairman of the Department of Electronic Engineering and Information Science. He was the vice-director of Academic Committee of USTC from 1993 to 2000.
Prof. Xu is a senior member of IEEE and the vice-director of the Chinese MTT Society. He is the Sub-Associate Editor of IEEE Microwave and Guided Wave Letters and vice director of the Editor Committee of Journal of University of Science and Technology of China as well as a standing member of the Editorial Board of the Journal of China Institute of Communications. Also, he is on the Editorial Board of IEEE Trans. on Microwave Theory and Techniques, the Progress in Natural Sciences, the Journal of Infrared and Millimetre Waves, the Journal of Electronics and Information, the Chinese Journal of Radio Science and the Journal of the Microwave, etc. During 1983-1986 as a Visiting Scholar he worked at the Polytechnic Institute of New York (PolytechnicUniversity) U.S.A. From September 1991 to February 1992 and from March to August 1993 he was a guest scientist and visiting professor at the WurzburgUniversity, in Wurzburg, Germany. From June to December 1998 and July to December 2000, he was a full professor at the Research Institute of Electrical Communication, TohokuUniversity, in Sendai, Japan. Also, he was a visiting professor or an academic visitor at several universities in the Unite States, Canada, Japan, Germany, Korea and Hong Kong. He was invited to be as a General Chairman of International Conference and a Chairman or member of the TPC and International Adviser Committee,an invited speaker and session chairman of many International Symposia.
Prof. Xu has been teaching many courses for more than 35 years for graduate or/and under graduate students. Such as: Foundation for Microwave Engineering, Microwave Network, Microwave Measurements, Microwave Components and Design, Millimetre Wave Transmission Structures, Theory of Dielectric Waveguides and Periodic Structures, and Numerical Method for Electromagnetic Fields.
Prof. Xu has been engaged in research in the fields of microwave, millimeter and optical wave theory and techniques and has been participating in many research programs in cooperation with both international and domestic institutes and industrial laboratories. He received the first award for the natural science given by the Chinese Academy of Sciences; the first award for science and technology given by the Kwang-Hua Science and Technology Foundation; the second award for the science and technology given by Anhui Province; the second and the third award for the science and technology advances given by the Chinese Academy of Sciences. He has published over 360 papers in variety of academic Journals and Conference Proceedings. His research interests are in the areas of nonuniform dielectric waveguides and applications, numerical techniques in electromagnetic and millimeter wave technology. His biography was listed in Who's Who in the world published in the U.S.A. and in the Dictionary of International Biography published in U.K.
Professor Yunsheng Xu
Dr. Yun-Sheng Xu was born in Jiangsu, P. R. China, on Nov.11, 1961. He received BS and MS degrees Engineering from the University of Science and Technology of China (USTC), in 1982 and 1984, respectively, and Ph.D. degree in Engineering from the Technishe Universitaet Hamburg-Harburg, Germany, in 1993.
From 1984-1988 he was with the Department of Electronic Engineering and Information Science at the USTC as an assistant and later a lecturer. Since 1994, he has been again with the same Department, where he is now a Professor and vice chairman of the Department. His current research interests are in the areas of the electromagnetic wave scattering and radiation, numerical techniques, and planar circuits.
Associate Professor Qi Zhu
Dr. Zhu Qi was born in Anhui province, P. R. China, on Jan.24, 1968. He received the BS and MS degrees both in applied physics from the Hefei University of Technology in 1989 and 1992, respectively, and Ph.D. degree in aircraft design from Nanjing University of Aeronautics and Astronautics in 1995. He has joined the faculty of the Department of Electronic Engineering and Information Science of USTC as a postdoctoral since 1996.
During the period of Ph.D. program, his work was mainly concentrated on the characteristic analysis of the airborne antennas, and EMC between these airborne antennas. All were supported by the Nanjing Electronic Institute and Nanchang Airplane-manufacture Corporation. He has also done some research work on the design of the radomes for the z-8, z-9 helicopter for the navy ofP.R.China. His current research interests include computational Electromagnetics,design of MIC/MMIC, scattering and propagation analysis.
Publications (1990-2002)
International Scientific Journals
[1]ZengXiangyin, XuShanjia, Wu Ke and Luk Kwaiman, "Properties of Guided Modes on Open Structures Near the Cutoff Region Using a New Version of Complex Effective Dielectric Constant", IEEE Trans. on MTT,Vol.MTT-50, No.5, pp.1417-1424, 2002.
[2]ZengXiangyin, Luk Kwaiman and XuShanjia, "Radiation and Leakage Characteristics of Transverse Slot in NRD Guide Operating LSE00 Mode", IEEE Trans. on MTT,Vol.MTT-50, No.6, pp.1636-1639, 2002.
[3]Xu Shanjiaand Lin Kaihui "Improved Perturbation analysis for a New Omni-DirectionalPeriodic Dielectric Rod Leaky Wave Antenna for Millimeter-Wave Application", Microwave and Optical Technology Letters, Vol.33, No.5, pp. 344-346, 2002.
[4]Jing Hengzhen and Xu Shanjia, "Brewster Angle Effect on Performances of a New MillimeterWave Omni-Directional Antenna Consisting of Circular Rod CorrugationsGloved with a Dielectric Shell", Microwave and Optical Technology Letters, Vol.33, No3, pp. 221-223, 2002.
[5]Lin Kaihui and Xu Shanjia, "Equivalent Network Analysis of Guidance and Leaky Characteristics of Asymmetric Groove Guide Antennas", International Journal of Infrared and Millimeter Waves, Vol.23, No.3, pp.445-457, 2002.
[6]ZengXiangyin, XuShanjia, Luk Kwaiman and Wu Ke, "A Novel Leaky Wave Antenna Based on NRD-Guide with Wedged Cross-Section", International Journal of Infrared and Millimeter Waves, Vol.23, No.4, pp., 2002.
[7]Jing Hengzhen and Xu Shanjia, "Brewster Angle Effect on Performances of a New Millimeter Wave Omni-Directional Antenna Gloved with a Dielectric Shell", International Journal of Infrared and Millimeter Waves, Vol.23, No.7, pp.1079-1089, 2002.
[8]Hiroyo Ogawa and Shanjia Xu, "Asia-Pacific Abstracts ---- Paper from Journals Published in Australia, India, Korea, China and Japan in 2001 ",IEEE Microwave & Wireless Components Letters, Vol.12, 2002.
[9]Xu Shanjia, Liu Jian and Mizuno Koji, "Dispersion Analysis of Birefringent Dielectric Grating Structure for Application in Pressure and Temperature Measurements", International Journal of Infrared and Millimeter Waves, Vol.22, No.3, pp.407-420, 2001.
[10]Xu Shanjia, Liu Jian and Mizuno Koji, "Numerical Analysis for the Transmission Characteristics of Different Kinds of Optical Fiber Gratings", International Journal of Infrared and Millimeter Waves, Vol.22, No.2, pp.315-328, 2001.
[11]Xu Shanjia and Jing Hengzhen, "Analysis of Dispersion Characteristics for a Circular Dielectric Rod Waveguide with Periodic Corrugations", International Journal of Infrared and Millimeter Waves, Vol.22, No.7, 2001.
[12]Xiangyin Zeng, Kwaiman Luk and Shanjia Xu, "A Novel Leaky NRD Guide with a Double-Layer Dielectric Slab", IEEE Trans. on MTT,Vol.MTT-49, No.4, pp.584-588, 2001.
[13]Yang Li and Xu Shanjia, "Analysis of Absorption Characteristics of Conductor-Grounded Lossy Dielectric Periodic Structures by Oblique Incidence", Chinese Journal of Electronics, Vol.10, No.3, pp.313-317, 2001.
[14]Mao Kaiyu and Xu Shanjia, "Transmission Characteristics of Curved Dielectric Waveguides with Arbitrarily Transverse Profiles", International Journal of Infrared and Millimeter Waves, Vol.22, No.12, 2001.
[15]Hiroyo Ogawa and Shanjia Xu, " Asia-Pacific Abstracts ---- Paper from Journals Published in Australia, India, Korea, China and Japan in 2000 ",IEEE Microwave & Guided Wave Letters, Vol.13, 2001.
[16]Liu Falin and Xu Shanjia, "E-plane Waveguide Filters with Partially Filled Dielectric Dielectrics for Wide Bandwidth", Microwave and Optical Technology Letters, Vol.31, No.3, pp.175-177, 2001.
[17]Zeng Xiangyin and Xu Shanjia, "Noteworthy Trap in Using the EDC Method for Solving Dielectric Waveguide Problems", International Journal of Infrared and Millimeter Waves, Vol.21, No.3, pp.437-446, 2000.
[18]Liu Falin, Xu Shanjia and Sheng Yijian, "An Alternate Method for the Analysis of a Waveguide-Loaded Cavity", Microwave and Optical Technology Letters, Vol.25, No.4, pp.283-285, 2000.
[19]Lee M.T., Luk K.M., Xu S.J. and Yung E.K.N., "Leaky Wave Antenna Based on Image NRD Guide with Staircase-Shaped Dielectric Slab", IEE Electronics Letters, Vol.36, No.13, pp.1102-1103, 2000.
[20]Xu Shanjia and Jia Dongyan, "3-D High-Order Edge-Element Analysis of 3-D Discontinuity Problems in Guiding Wave Structures", International Journal of Infrared and Millimeter Waves, Vol.21, No.4, pp.603-620, 2000.
[21]Mao Kaiyu and Xu Shanjia, "AnAlternative Method to Analyze Field Distribution in Curved DielectricWaveguides", International Journal of Infrared and Millimeter Waves, Vol.21, No.8, pp.1321-1330, 2000.
[22]Yang Li and Xu Shanjia, "Scattering Analysis of Dielectric Periodic Structures by an ObliqueIncidence", International Journal of Infrared and Millimeter Waves, Vol.21, No.11, pp.1807-1823, 2000.
[23]Yang Li and Xu Shanjia, "Multimode Network Analysis of Absorption Characteristicsof Lossy Dielectric Periodic Structures" International Journal of Infrared and Millimeter Waves, Vol.21, No.10, pp.1723-1735, 2000.
[24]Wei Choungyu, Xu Shanjia and Wang Dongjin, "A New Method for Determining the Location and Length of a Thin Cylindrical Target with Range Difference of a Multistatic Radar System", Journal of Electronics, Vol.17, No.2, pp.139-145, 2000.
[25]Wei Choungyu, Xu Shanjia and Wang Dongjin, "Analysis of Target Tracking Based on Range Difference Measurement of Multistatic Radar System", Journal of Electronics, Vol.17, No.4, pp.297-303, 2000.