Optimal FIR filter design for uncertain 2–1 Sigma-Delta modulator via curve fitting method

Uncertain components in the integrators of 2-1 Sigma-Delta modulators cannot cancel first stage noise and reduce the signal-to-noise ratio. Previous filters whose design is based on convex optimization are mathematically complicated and not very efficient in application. In this paper, we propose a method based on curve fitting which is simple and practical. Simulation results show that the optimal filter performs better than other filters.