A Compact, Injection-Moldable, Broadband Waveguide Polarizer

A compact and broadband waveguide polarizer for single-circular polarization is presented. As currently optimized, the novel development offers up to 45% of continuous bandwidth while enabling diverse manufacturing such as injection molding or conventional machining. Manufacturing diversity is achieved through the use of robust ridges in the waveguide which run flush to the polarizer backwall. The ridges also facilitate a joint optimization of amplitude difference, phase difference and internal reflections which gives rise to a multiplicity of axial ratio nulls. The developed feed cavity contains no undercuts and readily accepts draft angles up to three degrees without significant performance degradation. Furthermore, the performance offered exceeds that of traditional corrugated polarizers or loaded septum polarizers while accomplishing order-of-magnitude cost reduction when feed quantities are high.