An extremely broad-band waveguide polarizer

A quarter-wave waveguide polarizer with high isolation over a very large bandwidth has been developed. It consists of a rectangular waveguide with loads on all four walls. The theoretical bandwidth is almost twice as high as for polarizers known from the literature. A prototype has been measured in the frequency range 10.95-14.50 GHz. The isolation is higher than 44 dB, insertion loss is below 0.06 dB and reflection loss is below -24 dB (VSWR <1.13). In the case of dielectric loading, the correct phase behavior can easily be achieved by using screws in the walls for phase adjustment.<>