A K-band Single-to-Differential Broadband Low Noise Amplifier with LC Anti-interference Network

This paper proposes a K-band single-to-differential low noise amplifier (LNA) fabricated in 40nm CMOS process. It is designed in two-stage cascode topology, and an on-chip transformer balun is inserted into the LNA to realize single-to-differential conversion. T-shaped inductive network is used as inter-stage matching network for broadband impedance matching, and two LC anti-interference networks are used for out-of-band gain suppression. The LNA exhibits a peak gain of 23.5 dB at 17 GHz with a 3-dB bandwidth of 5.8 GHz, and a minimum noise figure (NF) of 3.5 dB at 16.5 GHz. The whole chip consumes 30 mW of power and occupies an area (including the pads) of 0.51 mm ² .