A $Ka$ -Band $E$ -Plane Waveguide Magic-T With Coplanar Arms

In this paper, an E-plane waveguide power divider and a waveguide-to-microstrip transition are used to form a waveguide magic-T with four arms in the same E-plane. The input port of the original E-plane waveguide power divider acts as the difference port of the magic-T, and a waveguide-to-microstrip transition is utilized to realize the sum port. The four arms are in the same plane, and traditional matching elements, such as cones, wedges, pins, and irises are not needed. The proposed magic-T features easy connection, fabrication, and assembly. The principle and design procedure are described in detail. A Ka-band E-plane waveguide magic-T is designed, fabricated, and measured. A fractional bandwidth of 21% is achieved. The measured and simulated results show good amplitude, phase, and isolation characteristics validating the proposed magic-T.