Ultra-Wideband CPW-to-Substrate Integrated Waveguide Transition Using an Elevated-CPW Section

In this letter, an elevated-coplanar waveguide (ECPW) is proposed for an intermediate section of a coplanar waveguide (CPW)-to-substrate integrated waveguide (SIW) transition. The ECPW is used to attain a gradual mode matching and to achieve the consequent wide bandwidth. The measurement results show 70% fractional bandwidth at 10 dB return loss and 0.9 dB insertion loss from 19 to 40 GHz. We expe...