Modified magic tee phase-shifter

Abstract

A magic tee may be used as a microwave phase-shifter by placing adjustable short circuits in its symmetrical arms. A perfect impedance match will exist through the E- and H-plane arms if the distances from the short-circuits to the tee junction differ by (2n + 1)? g/4. The phase is shifted by simultaneously varying the distances from the short circuits to the tee junction. Orienting the symmetrical arms parallel to each other and replacing the E- and H-plane arms by coupling slots on opposite sides of the stucture simplifies the short-circuit driving mechanism and allows cascading of several phase-shifters. This modification is useful as a precision laboratory phase-shifter and allows the construction of a wide-angle scanning array.