Circularly Polarized Phase Shifter for Use in Phased Array Antennas

An X-band ferrite phase shifter has been developed for operational use, the size and electrical performance of which are favorably suited for use in a phased array antenna that requires minimum center-to-center element spacings of 0.537 /spl lambda/. The phase shifter has the same configuration as a Faraday rotator with a ferrite rod located at the center of a circular waveguide with an axially applied field. If a circularly polarized wave is passed through this geometry, a nonreciprocal phase versus current characteristic is obtained. The theory of operation of such a device is already well understood, so further elaboration is not necessary. Scharfman and others have described this type of phase shifter in the literature.