Research On Mode Conversion Antenna Technology Based On Diffraction Periodic Structure

Mode conversion and directional radiation are the core technologies in microwave application systems.With the rapid development of microwave application system in military,scientific research and modern communication,the traditional microwave mode conversion and directional radiation technology can not meet the needs of current miniaturization,high efficiency,new capabilities and other system applications.New microwave mode conversion and directional radiation technology has become the focus of research in the industry.In recent years,two-dimensional electromagnetic materials based on diffraction periodic structure have the advantages of small size,low profile,simple processing,free control of phase and polarization of electromagnetic wave,and have the ability to realize mode conversion and directional radiation in theory.Combining the diffraction periodic structure with mode conversion and directional radiation technology,exploring the technical feasibility of compact and efficient new type of variable mode and radiation devices has become the focus of this paper.In this paper,based on the theory of electromagnetic transmission and mode conversion of two-dimensional diffraction periodic structure,the theory and Simulation of the technology of diffraction periodic structure variable mode antenna are studied in detail.The main contents of this paper include the following aspects:1.Study on electromagnetic transmission theory of diffraction periodic structure.The electromagnetic transmission theory of the diffraction periodic structure is studied.The electromagnetic transmission characteristics,element type and phase shift characteristics of the diffraction periodic structure are analyzed in detail.The element is designed,which lays a theoretical foundation for the research of the variable mode antenna technology based on the diffraction periodic structure.2.Research on dual-mode multiplexing orbital angular momentum mode conversion antenna.Combining with the electromagnetic transmission theory of the diffraction periodic structure,by adjusting the phase compensation values of different elements on the transmission array,the waveform control of the radiation beam is preliminarily realized,and the conversion from quasi-Gaussian mode emitted by the feed to(+2)orbital angular momentum mode is completed.When the antenna works at the central frequency of 35 GHz,the gain is 18.3dBi.3.Research on TE01 mode conversion antenna based on phase correction principle.Using two different phase correction methods,TE01 mode conversion antenna based on step phase correction principle and TE01 mode conversion antenna based on continuous phase correction principle are proposed respectively.The simulation performances of these two antennas are compared and analyzed.When both antennas work at 35 GHz,the gain is 15.9 dBi and 16.7 dBi,respectively.4.Research on TE01 mode conversion antenna technology based on polarization correction principle.Based on the principle of polarization correction,a TE01 mode conversion antenna based on the principle of polarization correction is proposed.When the antenna works at 35 GHz,the gain reaches 18.7 dBi,and the polarization efficiency of a single linear polarization mode is 89%.The mode conversion and directional radiation of microwave are realized,which provides a new technical way for mode conversion and directional radiation of microwave.