Abstract
This letter presents a Ku-band fully differential low-noise amplifier (LNA) using current reuse technique and weakly saturated input SiGe heterojunction bipolar transistors (HBTs) pair. The proposed LNA design achieves a measured peak gain of 18 dB, a 3-dB bandwidth from 11.5 to 17.4 GHz, a minimum noise figure (NF) of 3 dB, and an input 1-dB compression point of −15-dBm while consuming only 6.4 mA from a 1.8-V supply voltage. By achieving a lower power consumption, the proposed design has an improved figure-of-merit (FoM) than the state-of-the-art works. Furthermore, by incorporating a digitally variable gain control, the proposed design can improve the dynamic range by 14.4 dB. The proposed design is fabricated in a 0.18- \mu \text{m} SiGe BiCMOS technology and occupies a core die area of 0.22 mm2 (excluding measurement pads).