Broadband right-angle transition from substrate integrated waveguide to rectangular waveguide

Abstract

A broadband <i>E</i>-plane right-angle transition from a substrate integrated waveguide (SIW) to a rectangular waveguide (RWG) is proposed. A stepped waveguide, a coupling aperture, and two inductive posts are applied to provide a good impedance matching between the SIW and the RWG. A back-to-back transition prototype is designed, fabricated, and measured at Ka-band. Measured results show a good agreement with the simulated one: the insertion loss of a single transition is &lt;;0.6 dB and the return loss better than 15 dB is obtained from 32.6 to 38.1 GHz. The broadband transition can be used in front-end circuits of millimetre-wave communication, radar, and measurement systems.