A Volterra series approach for the design of low-voltage CG-CS active baluns

A low-voltage active balun and amplifier is presented. The circuit uses a common-gate common-source (CG-CS) noise-cancelling topology with a simple distortion cancellation method to improve the IIP₃ performance of the balun-amplifier. A Volterra series analysis is employed to provide insights into the nonlinear behavior of the circuit. A chip was fabricated and the experimental test results show an average voltage gain for the balun-amplifier of 16.2 dB and a maximum IIP₃ of -3.8 dBm over the span of 0.3-2.4 GHz. The circuit exhibits a noise figure below 4.0 dB over the measured band and reaches a minimum of 3.2 dB. The chip uses a single 0.9 V dc supply and consumes 15.8 mW of power. The RFIC was fabricated using a standard 130 nm CMOS process.