Research On Broadband Circular Polarized Horn Antenna

As antennas are widely used in various fields,more and more antenna systems have adopted circular polarization to achieve the system's performance requirements for antennas.The circularly polarized horn antenna has good directivity and a wide working frequency band,and has a very wide range of applications in the fields of communication and navigation guidance.This paper studies the ultra-wideband horn antenna,and realizes circular polarization by connecting to a 90° power division phase shifter,which can be disassembled and replaced.The thesis conducted an in-depth study on the ultra-wideband quad-ridged horn antenna,made a detailed analysis of the principles of ridge waveguide and coaxial feeding,and optimized the matching cavity of the horn,and finally designed a working frequency band coverage 1-The 18 GHz dual-polarized ultra-wideband quad-ridged horn antenna,the simulation results show that the horn antenna port 1 is in the working frequency band: the voltage standing wave ratio is less than 2.5,and the gain is 5.6 to 16.4 d Bi;the port 2 is in the working frequency band: voltage standing The wave ratio is less than 2.5,and the gain is 5.2 to 15.8 d Bi.The horn antenna was tested in a microwave anechoic chamber after production and processing.The test results are: Port 1 is in the working frequency band: voltage standing wave ratio is less than 2.5,gain is 5.6 to 16 d Bi,and port 2 is in the working frequency band: voltage standing wave ratio is less than 2.5,the gain is 5 to 15.7 dBi,the test result is basically consistent with the simulation result.In order to make the quad-ridged horn antenna have circular polarization characteristics,the input port of the dual-line polarization horn antenna is equipped with an equal power division wideband phase shift network with a phase difference of 90° to achieve circular polarization in a certain frequency range.The wide-band phase-shifting network is within the frequency range of 8GHz to 12 GHz,and the standing wave ratio is less than 1.25;the amplitude difference of the two output signals is changed within 0.3d B;the phase difference is changed within 90°±1°.The addition of a broadband phase-shifting network enables the horn antenna to have circular polarization performance in a certain frequency band.The simulation results show that the axial ratio of the speaker in the frequency range of 8-12 GHz is less than 3,and the gain is greater than 10 d Bi,which meets the requirements of circular polarization performance.Replacement of 90° power division phase shifters in other frequency bands in the working frequency band of the horn antenna can also make the horn antenna have circular polarization performance in this frequency band.8-12 GHz 90° power division phase shifter has been put into processing.The processing was not completed due to the epidemic.90° power division phase shifters in other frequency bands are being designed and optimized.