A Reconfigurable Multirate Single-Bit Sigma Delta Modulator for Multi-Standard Wireless Radio Receivers

摘要

A novel low-power 2-1-1 cascade sigma delta (SD) modulator with single-bit quantizers for multistandard wireless radio receivers is proposed in the paper.In order to reduce the power dissipation,the multirate technique is introduced.The multirate modulator decreases the sampling frequency of the 1st stage integrators which primarily determine the power consumption of the total modulator.The resolution is compensated by improving the sampling frequency of the latter integrators.A feedforward path is added to suppress the harmonic distortion and attain high linearity over a wide bandwidth.The circuit nonidealities are analyzed,and the feasibility and efficiency of the modulator are demonstrated in time domain using Matlab/Simulink.A peak signal to noise ratio (SNR) of 85/ 81/ 65/ 63/ 55/ 45 dB is achieved over a 0.2/1/ 2/ 3.84/ 22/ 28 MHz channel bandwidth for GSM/ Bluetooth/ GPS/ WCDMA/ WLAN/ WiMAX mode.The simulation results indicate that the proposed modulator architecture meets the performance requirements of the communication standards mentioned above.