Flippable and Hermetic E-Band RWG to GCPW Transition With Substrate Embedded Backshort

In this article, a novel millimeter wave (mm-wave), fully hermetic and flippable transitioning structure between grounded coplanar waveguides (GCPWs) and rectangular waveguides (RWGs) is introduced. This transition, realized through standard printed circuit board (PCB) technology, can be employed to feed a waveguide (WG) compliant device on any face of a board given its flexibility in trace routing and component placement. The proposed structure utilizes a mix of transmission line and substrate integrated waveguide (SIW) interconnected with an in-substrate embedded back-short. The transition, in all its configurations, targets a fractional bandwidth (FBW) wider than 20% to cover the commercial $E$ -band spectrum. Moreover, at center frequency the predicted insertion loss (IL) for both normal and flipped transitions is 0.4 and 0.46 dB, respectively. Parametric and yield analyses, together with postmanufacturing inspections have been performed to assess the robustness of the design and to identify the critical manufacturing inaccuracies. The experimental validations confirm the wideband operation with an IL bounded below 2.3 dB for the worst case of a back-to-back configuration.