A coplanar-to-microstrip transition for W-band circuit fabrication with 100- mu m-thick GaAs wafers

Results on a via-hole interconnect that links a coplanar waveguide (CPW) on one side of a 100 mu m-thick GaAs substrate to a microstrip line on the opposite side are presented. The measured insertion loss of a pair of back-to-back connections is 0.3 dB between 26.5 and 40 GHz. A lumped-element equivalent circuit of this via-hole interconnect has been extrapolated to W-band and used to design amplifiers at 94 GHz.>