Research On The Design Of Multimode Horn Antenna

The multi-mode horn has the advantages of simple structure,wide bandwidth,low loss,large power capacity and convenient processing,and the radiation pattern of axial symmetry can be obtained according to actual needs,so it is widely used in microwave,millimeter wave and optical antenna feed system.The paper focuses on the calculation theory and analysis design of multimode horn.The main work is as follows:Firstly,the working principle and design method of the multi-mode horn are expounded.The higher modes TM11 and TE12 are excited at the waveguide discontinuities,and reasonably set the length of the phase shift section,can get the appropriate mode ratio and phase at the aperture horn,so the desired radiation pattern is obtained.On this basis,a flare-angle multimode horn is designed by using the mode ratio method,and the mode ratio at various sections is analyzed and calculated.The rotation axisymmetry radiation pattern of the multimode horn is achieved in the frequency band of 5GHz-6GHz.The equal bandwidth is 20%,and the antenna gain is 21 dBi.A dielectric ring loaded multimode horn is designed and its performance is analyzed,and the radiation pattern is rotated axisymmetric in the frequency band of 5.2GHz-6GHz.The antenna gain is 21 dBi.The dielectric ring loaded multimode horn has the characteristics of high gain and its drawback is that the size is large.A corrugated ring loaded multimode horn is designed and analyzed by simulation.The multimode horn has the radiation pattern of rotation axisymmetry in the frequency band of5.5GHz-6.5GHz.Single polarized corrugated ring loaded multimode horn is processed and tested.The measured impedance bandwidth is 60%.The measured results of the pattern show that the equalizing beam can be obtained in 5.5GHz-6.5GHz.The equalization level is about-10 dB.Its cross polarization level is lower than the main polarization level 25 dB,and antenna gain is 12 dBi,The measured results are in good agreement with the simulation results.A dual-polarized corrugated ring multimode horn is designed and simulated by using the Balanced feeding mode.Through simulation analysis,the equalizing beam can be realized in the designed frequency band.