学术报告会通知 题 目: Stopbands and Resonances Characteristics of Cylindrical EBG Structures 报告人: Professor Kiyotoshi Yasumoto (College of Information Science and Technology , Nanjing Forestry University Professor Emeritus , Kyushu University , Japan) 时 间: 2012年4月5日（周四）下午15:00-16:00 地 点： 东南大学(四牌楼校区)李文正楼6楼614会议室 主 办： 东南大学毫米波国家重点实验室 IEEE AP-MTT-EMC Joint Nanjing Chapter 江苏省电子学会天线与微波专委会 摘 要: Periodic dielectric or metallic structures are a subject of continuing interest because of their wide use for microwave and optical wave components. A periodic array of circular rods is typical of a discrete periodic structure. The electromagnetic response is characterized by the scattering properties of the individual rod and the multiple interactions among the rods periodically situated. Various analytical or numerical techniques have been developed over the years to formulate the electromagnetic guidance and scattering from the periodic arrays. However, the previous pertinent efforts have been mostly concerned with the planar arrays. Recently, the cylindrically periodic structures have received a growing attention because of their potential applications to the designs of photonic crystal fibers and directive antennas or beam-switching antennas. In this talk, we shall investigate the frequency response of cylindrical electromagnetic bandgap (EBG) structures shown in Fig. 1. It consists of N-layered cylindrical arrays of circular rods with infinite length situated in a homogeneous background medium. The circular rods with radius are periodically distributed on each of N-concentric or eccentric circular rings with radii . The number of rods is chosen to be so that the structure has the common transversal period . The circular rods should be identical along one ring but those on different rings need not be necessarily identical in material properties and dimensions. Figure 1 shows a typical example of three layered structure with , , and . The initial excitation may be a plane wave, a line source, or a dipole source which is located at an arbitrary position in the structure. The cylindrical bandgap structure acts as a resonant cavity to the excitation source. The transmission spectra of the field radiated from the source through the cylindrical structure are analyzed using the semi-analytical approach, which has been formulated [1],[2] for layered cylindrical arrays of circular rods. Several interesting features of the scattered or radiated fields related to the stopbands and resonances of the structures are numerically demonstrated. [1] V. Jandieri and K. Yasumoto, “Stopband and resonance characteristics of cylindrical electro magnetic bandgap structures,” PIERS ONLINE, Vol. 7, No. 8, pp. 761-765, 2011. [2] V. Jandieri, K. Yasumoto, and Y.-K. Cho, “Rigorous analysis of electromagnetic scattering by cylindrical EBG structures,” Progress In Electromagnetics Research, Vol. 121, pp. 317-342, 2011. 报告人简介： Kiyotoshi Yasumoto received the B.E., M.E., and D.E. degrees in Communication Engineering from Kyushu University（九州大学）, Fukuoka（福冈）, Japan, in 1967, 1969, and 1977, respectively. From 1988 to 2008, he has been a Chair Professor of the Division of Electromagnetic Waves and Communications at the Department of Computer Science and Communication Engineering, Kyushu University. After his retirement in March 2008, he was conferred a title of Professor Emeritus, Kyushu University. He is currently a Special Professor at the Department of Electronics and Information Science, Nanjing Forestry University, China and a Research Fellow of Computer Science Laboratory, Fukuoka Institute of Technology, Japan. He was a Visiting Professor of the Department of Electrical and Computer Engineering, of University of Wisconsin, Madison, U.S.A. in 1989, a Visiting Fellow at the Institute of Solid State Physics, Bulgarian（保加利亚） Academy of Science and Institute of Radiophysics and Electronics, Czechoslovakian（捷克斯洛伐克） Academy of Science in 1990, a Guest Professor at the Department of Physics of Technical University of Ostrava（奥斯特拉发）, Czech Republic in 2000, and a Visiting Professor at the Department of Applied Electronics of University of Roma Tre, Italy in 2009. Dr. Yasumoto is a Fellow of Institute of Electrical and Electronics Engineers (IEEE), Optical Society of America (OSA), Institute of Electronics, Information and Communication Engineers (IEICE), Chinese Institute of Electronics (CIE), and Electromagnetics Academy at MIT, USA, and a member of Applied Computational Electromagnetics Society (ACES). His research interests are in electromagnetic wave theory, analytical and numerical technique in microwave and photonics, and wave interactions, radiation, and scattering in electron beam-plasma systems. | ||
|---|---|---|
