一种新的伴随调相测量方法

摘要

When to measure the incidental PM at AM,because in time domain and frequency domain, AM and FM are accompanied but not independent,so it's difficult to measure incidental PM.Traditional method by spectrum analysis is complex,and is only applicable to situation with small PM index. A new method is proposed:Under a particular frequency Relationship,by digital vector demodulation and sampling,to transform the AM and PM to magnitude error and phase error in IQ domain independently,on the measurement rules,there is analytical relationship between digital demodulation phase error and the analog incidental PM.For a total of 120 cases of parameters combination,experiment is carried out; the measurement results confirmed that the method is accurate.%在测量调幅的伴随调相特性时,从时域和频域来看,AM和PM的“相伴共生”,导致测量困难,传统的频谱分析方法计算和操作复杂度都较高、且只适用于伴随调相较小的情况.为此可以使用新的方法:在特定频率关系下,利用数字矢量解调抽样,在IQ平面将AM和PM转换到幅度误差和相位误差两个独立参量,在设定规则的测量条件下,矢量相位误差和伴随调相之间存在明确数学关系.实验验证中设置不同条件参数组合,共计120种情况,测量结果证实该方法是准确的.