数字接收机中的ADC性能分析

Analysis the Performance of ADC in Digital Receiver

模数转换器是连接模拟世界与数字世界的桥梁,在无线电数字接收机中,它的输入信号是模拟信号,经过采样和量化之后变成了数字信号。基于软件无线电思想,为减少模拟环节,数字处理功应能尽可能靠近天线,,因此ADC的性能就显得非常的重要。文章着重分析了ADC的交流性能,包括ADC的SNR与SFDR,讨论了ADC与射频前端电路匹配、时钟抖动与相位噪声转换和增益控制范围问题,最后对相关折衷考虑做了综合分析。

Analog-to-digital converter is a bridge between the analog world and digital world, in the radio digital receiver, its input signal is analog signal, after sampling and quantization into a digital signal. Based on the idea of software defined radio, in order to reduce the analog link, the digital processing functions should be as close to the antenna as possible, so the performance of ADC is very important. This paper focuses on the analysis of the ADC＇s AC performance, including ADC＇s SNR and SFDR, discusses the problem of ADC and RF front-end circuit match, clock jitter and phase noise conversion and gain control range, at last, a comprehensive analysis was made on the relative tradeoff.