A 24-32GHz gm-boosted LNA with Triple Coupling Input Transformer for 5G Applications

A broadband low noise amplifier (LNA) for a high data rate 5G millimeter-wave communication system is proposed. Designed in a general purpose 65-nm CMOS process, the LNA consists of a differential g _m -boosted common-gate (CG) stage followed by an open-source follower buffer. A novel compact three-coil transformer is employed to perform single-ended to differential conversion, broadband input matching, g _m -boosting and noise suppression at the LNA input. A transformer-based inter-stage couple network is used to broaden the overall amplifier bandwidth and to convert the differential signal to a single-ended output. The proposed LNA achieves a power gain of 15 dB with a 3-dB bandwidth of 8.9 GHz (ranging from 23.3 to 32.2 GHz), and a noise figure between 3-3.8 dB. The input S ₁₁ remains below -13.9 dB in the passband while the IIP ₃ is better than -1.7 dBm. The LNA consumes 13.5 mW from a 1.2 V supply.