X-band compact septum polarizer design

Circular polarization is commonly required in low noise receiver systems for radio astronomy, satellite communications and etc. Septum polarizer which is the essential passive component of receiver constitutes a simple and compact device for converting linear polarization into circular polarization and vice versa. In this paper, design and analysis of a compact septum polarizer with double-plane steps in rectangular waveguides as well as experimental results are presented. The intention of designing such a device arises from the building of cryogenic receiver at X-band (8-9 GHz) servicing for Shanghai 65m radio telescope which is the key project of Shanghai city. The design procedure and approach of septum polarizer have been validated with experimental results.