Substrate integrated waveguide E-plane tapering in low-temperature co-fired ceramic

This letter discusses the design, manufacture, and characterization of a substrate-integrated waveguide E-plane tapering. The tapering facilitates the integration of two waveguides with varying heights for, that is, conductor-backed coplanar waveguide to rectangular waveguide integration. A simultaneous top- and bottom-sided, λ/4-based stepped tapering for the 71–86 GHz band is designed using low-temperature co-fired ceramic technology. The fabricated design is measured using two E-plane taperings in back-to-back configuration. The reflection coefficient better than −11.8 dB, and the transmission coefficient larger than −1.4 dB at the full 71–86-GHz range for a single tapering is extracted from the measurement using time-gating.