A 67-110GHz CMOS to WR-10 waveguide transition using wirebonds and wideband microstrip launcher

In this paper a two-step transition between a CMOS chip and a WR-10 waveguide is designed and implemented. First, a CPW on Duroid to W-band aluminum waveguide is realized with a bandwidth of 49 % (67-110 GHz), an average insertion loss of -0.35 dB and reflection loss below -10 dB throughout the entire band. Then, wire-bonding the CMOS G-S-G pads to the Duroid CPW introduces an average 0.2 dB loss in the W-band. A 100 GHz RF signal of a 90nm CMOS VCO was transmitted successfully using this transition with less than 2 dB loss (which includes a 2-cm Duroid CPW line) compared to on chip probing measurement results.