Ultrawideband very low noise amplifier with noise reduction and current reuse

Abstract

A novel and useful noise reduction technique that improves the noise figure (NF) of a common-source (CS) low noise amplifier (LNA). The technique exploits dc current reuse and increases transconductance of the CS transistor while maintaining its power consumption. By using noise reduction and dc current reuse techniques, the thermal current noise of the noise cancellation stage is reduced without adding any extra branch to the circuit. As a result, the current thermal noise of second stage decreases dramatically leading to better NF without consuming any extra power. Moreover, since the circuit block is implemented using a pMOS transistor, the second order nonlinearity of pMOS and nMOS transistors cancel each other, resulting in improved nonlinearity performance of the LNA, including improvements to both IIP2 and IIP3.