Design of Compact D-Band Amplifiers With Accurate Modeling of Inductors and Current Return Paths in 55-nm SiGe BiCMOS

This letter presents 1-stage and 2-stage compact D-band amplifiers with lumped-element matching networks implemented in 55 nm SiGe BiCMOS. To correctly account for the effects of a nonideal ground plane, i.e., reactances in current return paths, and coupling of inductors with nearby layout structures, a shielded 2-port, 4-terminal simulation strategy for inductors is proposed. Validated by measurements, the approach allows very accurate design of compact amplifiers in D-band. The 1-stage design proves 11.8 dB gain at 152 GHz and 17.9 GHz bandwidth in 0.031 mm
²
. With the 2-stage amplifier, featuring 20.1 dB gain at 150 GHz with 24.5 GHz bandwidth in 0.058 mm
²
, from 2× to 5.7× area reduction is demonstrated against similar SiGe amplifiers in the same frequency band.