E and H-plane wide-band ridge waveguide couplers

A systematic synthesis procedure for ridge waveguide branch line couplers in both E‐plane and H‐plane configurations is presented. Ridge waveguides are chosen to benefit from their wide mono‐mode band and compact size compared to rectangular waveguides. Equivalent circuit parameters are used to synthesize the coupler sections. Rigorous mode matching method is used for full‐wave analysis and optimization of the couplers. Ridge couplers both in empty waveguide and Low Temperature Co‐fired Ceramic “LTCC” technology are designed using the proposed method and the design is verified with another numerical method. A prototype is built and its response is measured to verify the approach. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.