《成功测量噪声系数的 10 个技巧》.pdf

A P P L I C AT I O N N O T E 10 Hints for Making Successful Noise Figure Measurements Optimize Your Measurements and Minimize the Uncertainties Introduction Noise figure is often the key to characterizing a receiver and its ability to detect weak incoming signals in the presence of self-generated noise. The process of reducing noise figure begins with a solid understanding of the uncertainties in your components, subsystems and test setups. Quantifying those unknowns depends on flexible tools that provide accurate, reliable results. Find us at Page 1 Keysight Technologies, Inc. noise figure solution set—instruments, applications and accessories—helps you optimize test setups and identify unwanted sources of noise. We’ve been providing noise-figure test solutions for more than 50 years, beginning with The checklist in Appendix basic noise meters and evolving into solutions based on spectrum, network, and noise- A is a helpful tool to verify figure analyzers. that all hints have been considered for a particular The 10 hints presented here will help minimize the uncertainties in your noise figure measurement. measurements—whether you are designing for good, better or best performance in your device. Key topics include minimizing extraneous signals, mismatch uncertainties, nonlinearities, and path losses. HINT 1: Select the Appropriate Noise Source ENR The output of a noise source is defined in terms of its freque