Dual-mode sigma-delta modulator for wideband receiver applications

Abstract

This work presents a new sigma-delta modulator (SDM) architecture for wide bandwidth receiver, which contains dual-bandwidth for WCDMA and GSM system applications. This is a multistage architecture with a low-distortion swing-suppressing SDM and an interpolative SDM cascaded together. By the low-distortion and swing-suppressing technique, the resolution can be improved even under non-linearity effects. The interpolative SDM is to repress the high-band noise. The proposed SDM was designed and simulated by the 0.25-/spl mu/m 1P5M CMOS technology. The simulated peak SNDR for WCDMA is 72dB and for GSM is 82dB.