A performance study of circular polarization selective structures

A circular polarization selective structure (CPSS) reflects one handedness of circular polarization and transmits the other. In this paper the performance of a number of classical CPSS designs has been evaluated at the center frequency of operation for all possible spherical incidence angles. The results are presented in a compact way using two dimensional contour plots to represent the return loss, insertion loss and polarization purity of the transmitted and reflected signals. The results indicate that all CPSS designs presented up to date have preferred incidence planes of operation. The existence of geometrical symmetries in the designs affect the performance stability of the structures with respect to oblique angles of incidence. Applications of CPSSs in satellite communication systems, for example as a circular polarization dual aperture antenna or a circular polarization diplexer, require the structures to operate at wide ranges of oblique angles of incidence, making this type of analysis crucial for future development and evaluation of circular polarization selective structures.