Circular-to-rectangular waveguide diplexers

Design of circular-to-rectangular waveguide diplexers with circular waveguide as common port is presented. A ridged circular-to-rectangular waveguide T-junction is proposed as diplexing manifold. Full-wave optimization is used in the diplexer design. A Ka-band H-plane circular-to-rectangular waveguide diplexer is designed. Measured results are in good agreement with computed results.