Design of a Wideband Right-Angle CPWG-to-Waveguide Transition for Ku-Band Applications

Abstract

This letter presents a novel wideband planar coplanar waveguide with ground (CPWG)-to-rectangular waveguide (RWG) transition designed for Ku-band applications. The architecture employs a stacked patch structure integrated with shorting via walls, which are pivotal for mode conversion. The design incorporates dual matching techniques—mode and impedance matching—to extend the bandwidth. Specifically, the cross-slot magnetic currents induce an E-field that aligns with the TE10 mode of the waveguide, while the matching elements effectively suppress the undesirable higher order TM11 mode resonance. The transition operates over a bandwidth of 10.5–15.8 GHz ( $\Delta f =39.7$ %) with corresponding total insertion losses (ILs) maintained below 1.33 dB. The transition demonstrates an IL of up to 0.7 dB within its operational bandwidth.