Compact Ultrawideband Grounded Coplanar Waveguide to Substrate Integrated Waveguide Tapered V-Slot Transition

Abstract

In this work, a new ultrawideband grounded coplanar waveguide (GCPW) to substrate integrated waveguide transition is presented. The proposed design improves the performance of the triangular tapered slot transition, by providing a return loss level better than 28 dB in the $X$ -band frequency range (with enhancements of up to 29 dB at higher frequencies in such a band) and a flatter response for the insertion losses. The analysis of the new transition is performed using a dielectric material with high permittivity ( ${\varepsilon _{r}=9.8}$ ), which leads to an extremely compact implementation. In order to validate the proposed design, several back-to-back transitions with different lengths were manufactured, measured, and compared with the simulated data. Further experimental results, after performing an additional thru-reflect-line calibration for deembedding undesired effects of involved connectors, are also shown.