Research And Design Of High Power Microwave Antenna Based On Waveguide

Waveguide antenna system used in the microwave field, although there are many advantages, but there are still deficiencies: first of all, in the high power application ability is poor, electromagnetic waves radiated by feed and past by waveguide will appear the phenomenon of beam focusing, focusing electric field intensity is huge,when the antenna under high power conditions or thin atmosphere of space borne environment work, may lead to discharge phenomenon; second, the antenna system efficiency is not ideal, how to improve feed source, beam waveguide, and how to optimize surface antenna need further research and discussion.The research of feed source mainly focused on corrugated conical horn and Gauss pattern matching. First according to the existed various horn, then I use the tools such as HFSS and FEKO, to design the horn antenna which meet the requirement of radiate more component of gauss beam. The beam waveguide research mainly concentrated in reducing the losses of energy in the transmission system, and optimization of the amplitude and phase. Beam waveguide design mainly start with the position of the plane mirror, the angle of the choice and size of the curved mirror.Currently in order to improve the efficiency of the antenna mainly adopts two ways.(1) keeping reflecting system unchanged, I optimize the direction graph of feed, which radiate higher Gauss beam, this feed can irradiate surface antenna uniformly, and missing energy is very small.(2) Keeping pattern unchanged, I optimize the reflection system. it is to modify reflecting surface of antenna, so as to get uniform illumination to improve the efficiency of the main reflector aperture.This paper studied the whole system of beam waveguide reflector antenna, and investigated piece type mode converter, the original mode converter used in this example will efficiency lower than 80% and power capacity is relatively low, through the analysis and calculation get the solution method, to increase an outer layer to expand waveguides and increase the power capacity, and improve the efficiency of transformation patterns. After studied of the characteristics of the Gaussian beam and the original design of horn antenna radiation, redesign the ladder type of dual-mode conical horn, and define the phase center, the coupling efficiency of fundamental mode of Gaussian beam is high, the radiation beam is standard bunching mode, is verysuitable for the application of the beam waveguide antenna. The beam waveguide is redesigned, and the electric field distribution in the beam waveguide is very good.Finally used geometrical optics method to analysis the correction process of reflecting surface antenna, and used Mathematica 9.0 programming to obtain the correction curve,modified dual reflector antenna aperture efficiency are greatly improved and avoid the shielding of vice-reflecting surface.