Research On Solid State Plasma Frequency Reconfigurable Antenna In X And Ka Band

Wireless communication system has the development direction of large capacity,multi-function and ultra-wideband.In order to meet this trend,antennas need to switch between different frequency bands and polarities automatically,so as to realize the data transmission and reception between devices in different communication environments.The solid state plasma antenna can be reconfigurable by applying the bias voltage,which has the advantages of flexible switching of working frequency and wide range of radiation direction.In this paper,solid state plasma reconfigurable antenna is studied in further,and the main research results are as follows:Firstly,a structure of S-PIN solid state plasma,which can be applied to different antenna forms,is designed and optimized to meet the requirements of different working environments.Its characteristics of semiconductor and microwave are studied,and the working principle of frequency and polarization reconfigurable antenna by solid state plasma is analyzed from the perspectives of carrier concentration and volt-ampere characteristics.Finally,the equivalent model of solid state plasma in simulation software is introduced,and the reliability of the equivalent model is verified by COMSOL multiphysical field simulation software coupling semiconductor and RF physical field.Secondly,a solid state plasma monopole antenna with reconfigurable frequency at X-band and Ka-band is designed.First,the transmission characteristics of S-PIN solid state plasma during conduction are verified.From the simulation results,it can be seen that the insertion loss of the antenna decreases significantly with the conduction of S-PIN solid state plasma.On this basis,the length of SPIN solid state plasma antenna is used to convert the working frequency.Through size optimization,the influence of the external bias circuit structure on the antenna performance is minimized.The bandwidth of the designed antenna in the two reconfigurable frequency bands was 11.18-12 GHz and37-37.83 GHz,respectively.Due to the limitation of processing technology,metal instead of S-PIN solid state plasma was used to complete the physical processing and testing.Thirdly,a frequency and polarization reconfigurable solid state plasma antenna is designed.The choice of two microstrips at different positions on the back of the dielectric substrate enables the antenna to switch between horizontal polarization and vertical polarization,thus realizing the reconfiguration of antenna polarization mode.A cross-slot structure is installed on the metal floor,and the solid state plasma is filled at the end of the slot branches.The equivalent length of the slot changes with the working state of the S-PIN solid state plasma.On this basis,the antenna array design is carried out by simplifying the unit structure.The designed slot array antenna has a frequency band of 8.75-9.15 GHz in X-band and the maximum gain of 6.28 d Bi.In the Ka band,the frequency band is 31.5-35.5GHz,and the maximum gain is 8.81 d Bi.The results show that the curves agree well with the simulation results except for the slight frequency offset and the distortion of the direction graph at some frequency points.