Novel Compact Waveguide Dual Circular Polarizer

A novel type of dual circular polarizer for simultaneously receiving and transmitting right-hand and left-hand circularly polarized waves is developed and tested. It consists of a -plane T junction of rectangular waveguide, one circular waveguide as an -plane arm located on top of the junction, and two metallic pins used for matching. The theoretical analysis and design of the three-physical-port and four-mode polarizer were researched by solving Scattering-Matrix of the network and using a full-wave electromagnetic simulation tool. The optimized polarizer has the advantages of a very compact size with a volume smaller than 0.8λ, low complexity and manufacturing cost. A couple of the polarizer has been manufactured and tested, and the experimental results are basically consistent with the theories.