Design and Simulation of a Ka Dual-Band Dual-Circular Polarization Septum-based Waveguide Polarizer-diplexer

In this paper, a Ka dual-band dual-circular polarization septum polarizer-diplexer is proposed, designed and simulated for spatial systems and other applications. This waveguide-based structure is designed for 20-21 GHz and 30-31 GHz frequency ranges to generate/separate right and left hand circular polarizations. The polarizer has a septum structure that divides the waveguide in to two sections, one provides right hand circular polarization (RHCP) and the other provides left hand circular polarization (LHCP). Each section is connected directly to a waveguide-based diplexer, so the entire structure can transmit/receive both circular polarizations in dual-band. The septum polarizer, T-section, filters, etc., are designed and simulated. The designed septum-based waveguide polarizer-diplexer shows good return loss, insertion loss and isolation in the 20-21 GHz and 30-31 GHz frequency ranges.