Patent ID: 6967543

Claim:
A microstrip-to-waveguide power combiner comprising: a dielectric substrate; at least two microstrip transmission lines formed thereon in which amplified radio frequency signals are transmitted and terminating in microstrip launchers at a microstrip-to-waveguide transition; a waveguide structure positioned at the microstrip-to-waveguide transition such that said RF signals can transition from the transmission lines to the waveguide structure, wherein the waveguide structure is configured to power combine the RF signals with no significant additional losses beyond a loss inherent in said waveguide structure in the transition from the microstrip lines to the waveguide structure, said waveguide structure comprising a waveguide opening positioned at the transition and a waveguide back-short positioned opposite the waveguide opening at the transition; a metallic plate on which the dielectric substrate is supported, and a back-short cavity formed within the metallic plate at the transition to form the waveguide back-short; and isolation/ground vias formed within the dielectric substrate and around the transition that isolates the transition.