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

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 ¿m AMS CMOS standard technology and simulated with BSIM3 model. The circuit presents a 16dB dynamic gain variation in a 1.4-1.7GHz band (25dB of maximum differential gain), a phase and transducer gain magnitude errors less than 1.6° and 0.2dB, respectively, in a 300MHz span, a 1.24dB noise figure at maximum gain, a -23dBm input-referred 1dB compression point at maximum gain, a -12dBm IIP3, 50¿ input and output match, while drawing less than 7.5mA from a 1.7V power supply, including analog and digital system.