2004 Volume 1 Issue 3 Pages 57-62
This work presents a cascaded fourth-order ΣΔ modulator for multimode baseband-frequency (BF) receiver. Each stage of the proposed modulator contains a resonator that introduces a pair of conjugate zeros to minimize the in-band noise, and furthermore provides optimum noise transfer functions for multimode receiver. The proposed modulator also features low distortion, swing suppression, and high dynamic range (DR). As the simulation results, the DR of our multimode cascaded ΣΔ modulator is approximately 80dB for four wireless standards.