A Wideband CMOS LNA Integrated with Balun and Linear Digital Gain Control

Abstract

Design and simulation of a wideband monolithic single-ended-input/differential-output low noise amplifier, with active balun and digital gain control integrated on the same die, is described. The digital circuit comprises an internal 6 bit DAC and a 4 bit input logic control, allowing the gain response to have a linear approximation with 16 dynamic levels. The fully integrated circuit was implemented in a 0.35 mum AMS CMOS standard technology and simulated with BSIM3 model The circuit presents a 16 dB dynamic gain variation in a 1.4-1. 7 GHz band (25 dB of maximum differential gain), a phase and transducer gain magnitude errors less than 1.6deg and 0.2 dB, respectively, in a 300 MHz span, a 1.24 dB noise figure at maximum gain, a -23 dBm input-referred 1 dB compression point at maximum gain, a -12 dBm IIP3, 50 Omega input and output match, while drawing less than 7.5 mA from a 1.7 V power supply, including analog and digital system.