A D-band SiGe differential amplifier with 20 dB power gain and 30 GHz bandwidth

In this paper, a 102–132 GHz differential amplifier based on IBM 0.13-μm SiGe BiCMOS technology is presented. The amplifier consists of four differential pair stages in cascode structure with gain-boosting technique, a T-type matching network is optimized for wide bandwidth, and modified wideband March and baluns are employed for the testing requirement. The simulation results demonstrate that the modified March and balun obtains an insertion loss (i.e., S
21
and S
31
) of 3.1–4.2 dB at 90–150 GHz, the amplitude imbalance and phase imbalance between the two output ports is less than 1.1 dB and 7°. Under 1.8V supply, the differential amplifier achieves simulated results of 21.7 dB peak small-signal gain with 3-dB bandwidth from 102 to 132 GHz, 10.2 dB minimum noise figure, and −3.3 dBm output P
1 dB
at 120 GHz. The circuit size is only 1 × 0.62 mm
²
including baluns and testing pads.