Design of K/Ka-Band Diplex Circular Polarizer with High Isolation

A K/Ka-band diplex circular polarizer with high isolation is proposed in this paper, which is composed of a septum circular polarizer and a wide-band metal iris waveguide diplexer. The septum circular polarizer is utilized to realize the dual-band circular polarization, while the metal iris waveguide diplexer will provide dual channels with high isolation characteristic. The simulated results show that the proposed diplex circular polarizer operating at 19.6-23.5GHz and 27-31GHz, with a high isolation larger than 80dB and an axial ratio lower than 3dB, the whole size is 92mm×Φ20mm, which has the merits of dual-channel, high isolation, circular polarization and miniaturization.