Analysis of Nonlinear Distortion in Direct Sampling Mixers

Recently, improvement of CMOS process has made reconfigurable, single-chip digital transceiver possible. In a digital transceiver, Direct Sampling Mixer (DSM) is a circuitry that performs down-conversion, filtering, and decimation. Conventionally, an analysis of DSM has been treated by replacing each procedure into linear filters. However, because DSM has a nonlinear characteristic for its amplifier and switch, detail analysis can't be achieved by linear analysis. In this paper, we consider the nonlinear characteristic of DSM and show the simulation results of nonlinear distortion; AM/AM and EVM.