A 2.4GHz CMOS balun/LNA for IEEE 802.11b/g WLAN transceiver

This paper describes the design and simulation of an innovative monolithic active balun integrated with low noise amplifier. The Single-ended to differential signal transformation circuit comprises a differential signal generation circuit, which is able to receive a single-ended signal and generate a pair of signals having a 180 degrees(differential) relationship phase. The fully integrated circuit was implemented in a 0.35 mu m AMS CMOS standard technology. The simulations of the circuit, optimized to noise performance, minimum differential phase and magnitude error, were performed with BSIM3 model. The complete circuit presents 20.6dB of differential power gain at 2.4GHz, a phase and a transducer gain magnitude errors less than 0.2 degrees and 0.04dB, respectively, in a 1GRz span around 2.4GHz, a 3.7dB noise figure, a 2dBm output-referred 1dB compression point, 50 Omega input and output match, while drawing 11mA from a 3V power supply.