Novel design for coplanar waveguide to microstrip transition

A new design of a coplanar waveguide (CPW) to microstrip transition is presented. Simulation using the high frequency simulator software (HFSS) shows that a bandwidth of 13 GHz with less than -25 dB return loss can be achieved. The transition was fabricated and characterized. Experimentally, the S/sub 11/ of two back to back conductor backed CPW to microstrip transitions on InP substrate is better than -12 dB up to 14 GHz. For alumina substrate the S/sub 11/ was less than -15 dB up to 25 GHz.