Design And Research Of Novel Waveguide Circular Polarizer

Waveguide circular polarizer is an important part of the antenna feed system,which is widely used in the reflector antenna feed system.The function of it is to achieve the conversion between linear polarization signal and circular polarization signal and its performance is directly determine the merits of the entire feed system.The main research content of this paper is the septum circular polarizer.It is a kind of microwave device which can realize the simultaneous operation of left circular polarization and right circular polarization.The main research work is as follows: 1.Analysis and summary of waveguide circular polarizer.Through in-depth study of the literature on the waveguide circular polarizer,the advantages and disadvantages of various types of circular polarizers were analyzed.The septum circular polarizer was analyzed emphatically.2.Improved design of the conventional septum circular polarizer.The septum circular polarizer has the characteristics of tightening structure,easy processing and so on,but its bandwidth is only about 25%.After the deep study and analysis of the conventional septum circular polarizer,an improved septum circular polarizer was designed and its bandwidth is about 37%.3.Research and design of novel waveguide circular polarizer.Through in-depth study of the waveguide circular polarizer and combining the knowledge of OMT(Ortho-Mode Transducer),a novel waveguide circular polarizer whose working principle is different from the working principle of the conventional circular polarizer was proposed.Then,a novel waveguide circular polarizer which is working on X band was designed,and a physical processing structures was deigned too.At last,the correctness of the novel waveguide circular polarizer is verified by comparing the simulation results with the measurement results.The bandwidth of the novel waveguide circular polarizer is only about 10%,but its structure is novel and can be studied and improved a lot.