94 GHz bidirectional variable gain amplifier in 0.13-µm SiGe BiCMOS for phased array transmit and receive (T/R) applications

This paper presents a bidirectional variable gain amplifier (VGA) for W-band phased array transmit and receive (T/R) application. The VGA is based on cascode topology and employs T-type matching networks combined with load inductor and transistor parasitics to serve for both input and output matching when establishing directional signal flow. The VGA is implemented in a 0.13 µm SiGe BiCMOS technology. Measurement results show −1∼5.7 dB of gain control range, 9.5 dB NF, and −8.5 dBm IP
−1dB
at 94 GHz at the expense of 9.9 m W of power dissipation. The reverse isolation is better than −18 dB at 94 GHz. Chip size is 0.56×56 mm
²
including pads.