A broadband waveguide-to-microstrip transition/power splitter using finline arrays

A broadband waveguide-to-microstrip transition/power splitter, using a finline array for waveguide mode termination and then transferring the energy to microstrip lines with a broadband slot-to-microstrip transition, is presented. A single baek-to-back and a four-element transition covering the X-band were designed, fabricated, and tested. Adapting the concept of microstrip-slot pulse inverter, another two-element array is also fabricated with wideband 180° out-of-phase outputs. The effects of the waveguide grooves for mounting the substrate are also investigated. By using multiple fin line tapers on one substrate, the proposed structure can be employed in spatial power combining/dividing applications. © 2007 IEEE.