A capacitor cross-coupled differential cascade low-noise amplifier

Abstract

A gm-boosting technique implemented by capacitor cross-coupling of common-gate devices in a differential cascode low-noise amplifier (LNA) is presented for improving the gain and noise figure (NF) without significant increase in current consumption. The conventional cascode LNA exhibits a relatively low performance at millimeter-wave frequencies due to carrier mobility limitations and device parasitic in the common-gate stage. A cascode LNA is designed in a 180 nm RF CMOS process at center frequency of 40 GHz. It achieves a gain of 8.8 dB and a NF of 4.2 dB while reverse isolation is better than -15 dB. The LNA circuit consumes 6.5 mW from a 1.8 V supply.