A 4.8dB NF, 3-to-119GHz Distributed LNA With Three-Turn Transformer and Multiple Magnetic Coupling Feedback Network in 28nm CMOS

This paper proposes a three-stage wideband distributed low-noise amplifier (LNA) with cascode unit cells. A three-turn transformer (3-TT) is introduced to optimize the noise contribution of the common-source transistor. A multiple magnetic coupling feedback network (MMCFN) with inductive peaking technique is employed to improve the gain and noise figure (NF) at high frequency. An RC-parallel terminal circuit (TC) is proposed to replace the input matching resistor, which suppress the noise contribution of the TC. Implemented in a 28nm CMOS process, the proposed distributed amplifier achieves a peak small-signal gain of 15.3dB with a wide −3dB bandwidth across 3 to 119GHz. A GBW of 675GHz is obtained. The NF is from 4.8 to 9dB within the −3dB bandwidth. The circuit consumes a current of 65mA from a supply of 1.9V and 1.6V with a core chip area of 0.37mm².