频谱仪灵敏度分析及小信号测量的修正

Sensitivity Analysis and Correction of Measuring Small Signal for Spectrum Analyzer

简述了超外差式频谱分析仪的组成及其工作原理,论述了微波频谱分析仪灵敏度的基本概念,给出了频谱分析仪灵敏度的计算公式,讨论了频谱分析仪灵敏度与噪声系数、分辨带宽和射频衰减的关系。研究了改善微波频谱分析仪灵敏度的方法:降低噪声系数法、压窄分辨带宽法和减小射频衰减法。讨论了频谱分析仪本底噪声对小信号测量影响的修正方法。

In this paper, the composition and operation principle of a superheterodyne spectrum analyzer are described simply. The basic conception of spectrum analyzer sensitivity is discussed. The calculation formula of sensitivity is derived. The relations of spectrum analyzer sensitivity and noise figure, resolution bandwidth and RF attenuation are discussed. The improvement methods of spectrum analyzer sensitivity are studied by decreasing noise figure, reducing RF attenuation, and reducing resolution bandwidth. Finally, the correction method of the effect of spectrum analyzer floor noise on small signal measurement is discussed.