Research On Orbital Angular Momentum Wave Antenna Based On Metallic Circular Waveguide

With the development of the internet and mobile communication,the business needs about the area is also growing,the living standard of people has got great improvement,but with the demands of various wireless communication transmission index increased,the frequency band of increasingly scarce resource utilization and bandwidth limits its wider application.The vortex electromagnetic wave carrying orbital angular momentum?OAM?in wireless communication has the characteristics of high frequency utilization,good anti-interference multiplexing and other technical features,and it is a method that can effectively improve spectrum utilization and enhance signal transmission,so that it has a broad prospect of development and application.Orbital angular momentum is widely used in optics,but it has not been fully developed in radio frequency field.In this paper,we take a further study on the generation of the vortex wave and the design of OAM wave antenna.Firstly,we introduce the background and the significance about vortex wave,summarize the research status of OAM,then,the basic concept and definition of OAM are discussed in details,Humblet angular momentum decomposition principle and relevant formulas are applied,then we conclude the generation and detection of OAM.There is a phenomenon of polarization degenerate in circular waveguide.By using the relevant characteristics of circular waveguide,different orthogonal modes can be generated,it will produce OAM modes with vortex phase factor after superimposing,so as to generate the corresponding vortex electromagnetic wave.Based on the background above,we design a new type of radiating antenna to generate OAM in circular waveguide by using the excitation of coaxial feeding structure,and we use the combination of TE₂₁1 mode and TM₀₁1 mode.The model structure and design parameters are optimized and discussed in the paper.