Duplexing Ferrite Reciprocal Phase Shifters

The basic structure of microwave ferrite reciprocal phase shifters of the Dual-Mode and Rotary-Field types can readily be adapted to incorporate the function of a circulator outside the phase shifting region. The circulator effect is realized in the form of orthogonal polarization of waves in the two directions of propagation in circular or square waveguide at the input of the device. A mode-separating waveguide junction is required to resolve these orthogonal modes into two single-mode waveguides. This paper presents specific implementations of duplexing ferrite reciprocal phase shifters, comments on the factors affecting the isolation of the equivalent-circuit circulator, and discusses possible advantages in antenna system applications.