Inductorless linearization of low-power active mixers

A high linearity subthreshold mixer with negative impedance generation is presented. The mixer configuration was formed by adding two cross-coupling capacitors to a conventional structure. Since the internal negative impedance generation of this construction cancels parasitic capacitances, the conversion gain loss due to the parasitic capacitances is alleviated and the linearity is improved. Small-signal model calculations with Volterra series are presented to analyze the effects of cross-coupling capacitors on IIP3 and conversion gain, confirming that this design approach can improve the IIP3. The mixer was designed in 130nm CMOS technology and simulated with extracted layout parasitics. Having a power consumption of 0.373mW and a layout area of 0.0323mm
²
, it achieves more than 9dB conversion gain and 14dBm IIP3 from 2.4GHz to 11.4GHz.