Rectangular waveguide based polarizer for mm-wave antenna measurements

A polarizer for mm-wave antenna measurements based on standard rectangular waveguide technology is presented. The polarizer features a compact design and exhibits full band coverage with an excellent return loss |S₁₁| ≤ -20 dB and a transmission coefficient |S₂₁| ≥ -2 dB. Furthermore, it has identical amplitude and phase responses in both the horizontal and vertical polarization states. This unique property enables accurate measurements in applications, which require dual-polarized signal acquisition such as near-field antenna or polarimetric radar cross section (RCS) measurements. Measurement results of a manually rotated prototype operating in the D-band (110-170 GHz) are shown. The design can be scaled to even higher mm-wave bands.