Design and Implementation of an Ultracompact LNA With 23.5-dB Gain and 3.3-dB Noise Figure

A 24-GHz compact gain-boosting low-noise amplifier (LNA) using transformer-based noise reduction and single-ended neutralization techniques, is presented in this letter. Based on a novel feedback transformer and a phase tuning capacitor, an improved capacitive feedback neutralization technique is introduced into a single-ended common source topology, converting the unstable transistor to a reliable, practical, and gain-boosting stage. The proposed LNA achieves a 23.5-dB transducer gain and a noise figure of 3.3-dB at 24 GHz with 12-mW power consumption. For a compact design, the matching networks are realized by transformers. The active chip area is optimized to 0.096 mm(2).