Design of A Circular Polarized Ku/K-Band Feed System for Reflector Antenna

According to the needs of research and application, a dual-band circular polarized feed system is proposed in this paper, which comprises two parts: the primary horn and the feed network. The system operates in the Ku/K bands with the band span ratio of 1.58: 1. Tx, Rx frequency ranges are from 21.4 to 22.9GHz and 14.5 to 16.5GHz respectively. In addition, the polarization methods of two frequency bands are left-handed and right-handed circular polarization independently. Then the feed network of this system is designed, which is mainly composed of circular polarizer, orthogonal mode transduces and low-pass filter. The overall simulation results of the system show that in the Ku/K band, the return loss of Tx/Rx ports of the network is better than 25dB, the axial ratio is less than 0.8dB, the isolation of both ports is greater than 150dB, and the cross polarization level is higher than 29dB.