Radiation receiving apparatus

摘要

A microwave receiving antenna system (30) is described which is used to determine an originating direction of microwave radiation. The system has a birefringement phase plate (34) which splits radiation incident on it into two components which undergo a differential phase delay as they pass through it. The amount of differential phase delay induced varies with angular position around the phase plate (34) from 0 at an angular position of 0° to lambd an angular position of 360°. By determining the differential phase delay (assuming a previously existing relationship) the originating direction of the radiation can be determined.