A Low-Power, $W$ -Band Phase Shifter in a 0.12 $\mu{\rm m}$ SiGe BiCMOS Process

This letter presents a loss-compensated, varactor-loaded transmission line for a W-band analog phase shifter in a 0.12 μm SiGe BiCMOS process. To compensate for distributed varactor losses, a variable gain amplifier is distributed along the transmission line. A phase shift of 65° over eight stages (8° per stage) is introduced from 70-110 GHz. A maximum gain of 16.7 dB or (2.1 dB per stage) at 94 GHz is measured. The output-referred P1 dB is typically -7 dBm with a total current consumption of 20 mA from a 1.8 V supply voltage. The chip occupies an area of 0.2 mm² including the pads. This is the first phase shifter at 94 GHz in silicon/silicon-germanium reported to date.