Research On Characteristics Of Enhanced Microwave Transmission And Application In The Antenna

The electromagnetic properties of metal-dielectric interfaces and the transmission characteristics of metal hole or slit and periodic corrugated structure have become a hot research, since Ebbesen reported the observation of enhanced transmission in the optical regime. They have been ushered in a new era in the study of optical materials and optical devices. However, much attention has been focused on noble metals in the optical regime, while fewer studies have been carried out in the microwave region. The researches of transmission enhance in the microwave region are significant, because they are potentially significant to the control of microwave properites, and the design of new microwave devices and superconducting film microwave nonlinear device, etc. In this article, it mainly analyses the enhanced transmission of the microwave regime and explores the application of the enhanced transmission in antenna design. A new kind of planar feeder antenna is introduced, by the analysis of several fundamental structures. It consists of a subwavelength annular aperture concentric corrugated conducting plate that produces small size, low profile, high gain and a narrow radiated beam, and it is potentially significant. The antenna is simulated by simulation software HFSS. As a result, the gain and emission directivity can be further improved, the gain enhances5.5dB and the direction has improved more than40degrees. The antenna is fabricated. Then it is measured in anechoic chamber and the experimental results are in good agreement with the simulation results.The details are as follows:(1) The thesis introduces the surface plasmons, composite diffracted evanescent wave and resonant cavity model which are current accepted models explanations on the phenomenon of enhanced transmission. Then it analyses their advantages and disadvantages.(2) The influence of physical parameters and structures to transmission enhance in microwave region is obtained by analyzing and optimizing the phenomenon of enhanced transmission of periodic hole array structure and periodic corrugated structure et al. some usual structures. The subwavelength annular aperture has higher enhanced transmission performance by contrast research. The annular aperture structure modified is chosen as the coupling structure.(3) In this article, a new corrugated planar antenna made of a subwavelength annular aperture surrounded by circular groove on the conducting plate is proposed. This structure displays good gain and directivity.A kind of new microwave antenna is designed by studying transmission properties of subwavelength metal structure in the microwave region. The study offers a necessary pre-exploratory for the development of microwave devices based on enhanced transmission.