Nonlinear analysis of Direct Sampling Mixers using F-matrix

Direct Sampling Mixer (DSM) is a circuitry that performs down-conversion, filtering, and decimation. However, one of the serious problems of DSM is nonlinearity due to low supply voltage. In addition, DSM has frequency conversion of periodically time-variant system due to some MOS switches and frequency response due to current sampling and filtering, and so generally this type of nonlinear analysis is known to be difficult. In this paper, we present the analysis method using Fundamental matrix with Volterra expansion function and frequency conversion. Then, we discuss the accuracy of this analysis method by the result of comparison with circuit simulation (ADS).