Compact coaxial-fed CP polarizer

This letter describes the design and performance of a coaxial fed linear to circular polarization converter. The converter is 50% shorter, and has superior bandwidth response than conventional spread-squeeze alternatives. The polarizer is realized using metal posts positioned inside a circular waveguide. In the example given here, right-hand circular polarization over the frequency range of 8.0-8.6 GHz is generated with input return loss better than 20 dB, and axial ratio less than 2.5 dB.