A High Performance I/Q Zero-IF Mixer with IIP2 Calibration Technique in 45nm SOI CMOS

This paper presents a high performance I/Q zero intermediate frequency (IF) mixer with a second-order input intermodulation point (IIP2) calibration technique in 45nm SOI CMOS process. A behavioral model of the mixer is established to analyze the sources of the second-order intermodulation distortion (IMD2). Based on the analysis, a high accuracy load resistance modulation array is applied to achieve excellent IIP2 performance. The frequency of the local oscillator (LO) signal is 3.5GHz, while the RF input signal frequency range is 3.4GHz ∼3.6GHz. Simulation results show that the proposed zero-IF mixer achieves a conversion gain of more than 9.2dB with the input 1dB compression point of -11.28dBm. Noise figure is about 16.9dB at 10kHz and lower than 11.6dB at the frequency above 1MHz. The IIP2 of the circuit is larger than 66dBm after the calibration, which increases more than 40dBm.