Compact duplexer-polarizer with semicircular waveguide (antenna feed)

A light, compact, and high-performance duplexer-polarizer able to generate circularly polarized waves in a circular waveguide is discussed. Two prototypes were built. The standing-wave-ratio (SWR) and ellipticity performances are extremely good (less than 0.15 dB ellipticity over 15% bandwidth). The experimental development was facilitated by the computation of the dispersion curves and of the transverse field distribution associated with the two fundamental guided modes propagating in the different sections of a septum waveguide.<
>