A 12.9-38.6-GHz CMOS LNA With Triple-Coupled Transformer-Based Input Matching Technique

Abstract

This paper presents a wideband millimeter-wave low-noise amplifier (LNA) in a 65-nm CMOS process. A triple-coupled transformer-based input matching technique is proposed to enhance the input power matching bandwidth. In addition, by leveraging a transformer between the two-stage common source (CS) amplifiers, the noise figure (NF) is reduced while the transconductance of the second stage is improved to extend the gain bandwidth. The proposed LNA is designed to achieve an ultra-wide 10-dB return loss bandwidth from 12.4 to 46.9 GHz. The effective input matching bandwidth is limited by the 3-dB gain bandwidth, which is from 12.9 to 38.6 GHz. It achieves a peak gain of 11.9 dB and a minimum NF of 3.2 dB. The third-order input intercept point (IIP3) is −0.45 dBm at 30 GHz. The proposed LNA occupies a core area of 0.18 mm2 and consumes only 5.1 mW.