A high IIP2 direct down-conversion active mixer calibrated by RLS adaptive filter

A system simulation for a high input-referred second-order intercept point (IIP2) in active mixer of direct-down-conversion (DCR) with adaptive filter calibration is proposed. According to the simulation results of Simulink, by adopting the RLS filter calibration, a DCR mixer working under GSM 900 can achieve an IIP2 enhancement from 53dBm to over 70dBm within 0.3ms. The comparisons between RLS and LMS adaptive filters utilized in DCR active mixer are also presented.