A Wide-Band CMOS to Waveguide Transition at mm-Wave Frequencies With Wire-Bonds

In this paper a two-step transition between a CMOS chip and a WR-10 waveguide is investigated. The transition between a coplanar waveguide (CPW) on Duroid to W-band aluminum waveguide is studied and measured results show a bandwidth of 49% (67-110 GHz), an average insertion loss of 0.35 dB, and return loss below 10 dB throughout the entire band. Wire-bonding is then investigated as a connection between on-chip CMOS ground-signal-ground (GSG) pads to the Duroid CPW where the CMOS to printed circuit board transition measured results show an average 1-dB loss (including the CMOS GSG launcher) in the W-band. The full transition is also used to demonstrate packaging of a 100-GHz voltage-controlled oscillator in 90-nm CMOS where the RF signal was transmitted successfully with an average 2.5-dB loss (which includes a 2-cm Duroid CPW line) compared to on-chip probing measurement results.