An IIP2 calibration technique for zero-IF multi band down converter mixer
Meeting the tough linearity and noise required by GSM and UMTS receivers in CMOS technology is challenging. A new IIP2 calibration technique based on canceling the second order nonlinearities of mixer, generated in the input RF transistors, is introduced. By using this technique about 22 dB mixer IIP2 improvement is achieved. The proposed calibration circuit can be used in multi-standard mixer because of high bandwidth of the calibration circuitry. Moreover it can work with voltage supplies as low as I V. Using this technique a multi-standard mixer supporting PCS, UMTS and IEEE802.1 1b-g is developed. The design is done in CMOS 65 nm technology with 1.2 V supply while it consumes about 7 mA current.
iip2 calibration mixer cmos multi-standard second order intermodulation