This paper describes the design of a 140-GHz low- noise amplifier in 130-nm SiGe BiCMOS technology. The circuit is aimed for a high integration-density imaging radiometer, where several receivers are integrated on the same die. Thus, we particularly focus on minimizing the die area and power consumption. The two-stage amplifier is composed of cascode stages with gain boosting base resonators. The performance of a single cascode stage is optimized by correctly sizing the base resonator to avoid instability and optimizing the compact transistor layout without typically used interstage matching between the cascode stages. The circuit features gain of 19 dB at 140 GHz, and noise figure of 7 dB, while consuming only 15 mW with the supply voltage of 2 V and occupying a die area of 0.1 mm².