Measuring filter response using a noise source
This entry was posted in measurement and tagged radio frequency, spectrum analyzer.
If you own a spectrum analyzer with tracking generator or, even better, a good vector network analyzer, measuring the frequency response of a filter is fairly easy. But there is one old approach using a noise source that can turn any oscilloscope with a FFT spectrum view into a useful tool for determining the frequency response of a filter.
The concept I will outline in this article is absolutely nothing new. Back in the days, engineers and hobbyists would use analog noise sources in combination with a spectrum analyzer to determine the frequency response of a filter. The concept is very simple: the wide-band noise source is connected to the input of the filter and the output of the filter is connected to the input of the spectrum analyzer…