A 28–37 GHz Triple-Stage Transformer-Coupled SiGe LNA with 2.5 dB Minimum NF for Low Power Wideband Phased Array Receivers

This work presents a transformer-based three-stage SiGe low-noise amplifier (LNA) implemented in the Tower Semiconductor SBC18S5 process. The design realizes wideband input matching using a T-coil network, and wideband interstage matching using coupled transformers. The LNA exhibits 20 dB gain with a 3-dB bandwidth > 9 GHz and has a minimum noise figure (NF) of 2.5 dB with 13 mW of power consumption. The LNA can also operate at 6 mW power consumption with only a 0.3 dB increase in the NF, and achieves 3 dB of gain for 1 mW of DC power consumption at 33 GHz. To the author's knowledge, this work presents one of the highest figure-of-merit (FoM) of mm-wave amplifiers with a center frequency above 30 GHz.