矢量信号分析中高性能模拟信号采集系统的研究

Research on high⁃performance analog signal acquisition system in vector signal analyzer

现代通信涉及大量先进技术,需要有与电子通信相关的测量仪器,以捕获和分析宽带、实时矢量信号。中频数字化技术是实现通信过程的先进手段之一。针对矢量信号分析仪中对中频模拟信号采集系统高性能的要求,文中对系统各部分设计进行简要分析,应用ADS与诺顿等效变换对系统前端模拟抗混叠带通滤波器进行设计、优化与仿真;根据有大动态范围与优良信噪比的高速ADC的工作要求,对应选用的采样时钟信号各项指标进行推导计算,并提出一种应用自适应技术提高高速ADC分辨率的方法。

The modern communication involves a large amount of advanced technology,and requires measurement instruments related to electronic communication to capture and analyze broadband and real⁃time vector signals.The IF(intermediate frequency)digitization technology is one of the advanced means to achieve the communication process.In view of the high performance requirements of the IF analog signal acquisition system in the vector signal analyzer,the design of each part of the system is analyzed briefly,and the analog anti aliasing bandpass filter at the front end of the system is designed,optimized and simulated by means of ADS and Norton equivalent transformation.According to the working requirements of high⁃speed ADC(A⁃D converter)with large dynamic range and excellent signal⁃to⁃noise ratio,various indicators corresponding to the selected sampling clock signal are deduced and calculated,and a method to improve the resolution of high⁃speed ADC using adaptive technology is proposed.