High-speed CMOS analog-to-digital converter for front-end receiver applications

Abstract

Modern front-end receivers perform direct conversion of an analog signal to digital form at intermediate frequencies (IF), simplifying the overall system design and alleviating the problems associated with IF mixers. The final aspiration is to directly digitize the RF signal and hence eliminate any RF/analog mixers. In order to direct digitize the analog input signal, a high dynamic-range and high-speed ADC is needed. Continuous-Time Bandpass Delta-Sigma Modulator can meet these specifications, using high-performance multi-bit quantizers. This article presents the design of a high-speed CMOS Analog-to-Digital Converter (ADC) to be used as a quantizer in modern digital receivers. It is designed in a 130 nm CMOS technology from STMicroelectronics. The main features of the ADC are 3-bit resolution with 4 GHz sample rate in a 0.8-2GHz bandwidth.