Advanced modeling technique for bandpass continuous-time delta-sigma modulators

Transistor-level simulations of complex circuits such as delta-sigma modulators (DSMs) that are used to generate highly accurate results are time consuming because of the nonlinear and switched nature of such systems. Therefore, high-level system modeling is required to reduce the simulation time and allow for effective initial design or successive iterations between system-level and transistor-level simulations. Accordingly, a precise behavioral modeling technique for radiofrequency (RF) continuous time (CT) DSM is presented. The main contribution of this work is the differential nature of the RF CT-DSM model in MATLAB such that is it suited for co-simulation in a circuit simulator environment. The modeling technique and simulation methodology are demonstrated toward the implementation of a 4^th order RF CT-DSM in MATLAB/SIMULINK environment and a description for each block is provided.