Bottom noise cancellation method based on spectrum analyzer

Abstract

The invention particularly relates to a bottom noise cancellation method based on a spectrum analyzer. The bottom noise cancellation method based on the spectrum analyzer comprises the steps of: (A),setting the attenuation value of the spectrum analyzer, and selecting a variable frequency channel according to the input signal frequency; (B), in a condition that a signal is not input, obtaining the bottom noise log power P0 of the spectrum analyzer by measurement under RBW0; (C), obtaining the linear normalized power Plin; (D), inputting a signal to be tested, and obtaining the total power P(x) of the signal and the noise under RBWx; (E), obtaining the input signal power Plog(s), the bottom noise influence of which is eliminated; (F), if measurement is ended, quitting the process, and otherwise, executing the next step; and (G), judging whether the test environment of the spectrum analyzer is changed or not, if not, returning to the step (C) to direct measure, and if so, returning to the step (B) to measure after re-calibration. Due to bottom noise cancellation of the spectrum analyzer, influence of the bottom noise of the spectrum analyzer on small signal power can be eliminated to the most extent; therefore, the low-power small signal measurement range is extended; and the method is very high in measurement efficiency and has practicability.

Description

technical field [0001] The invention relates to the technical field of electronic test and measurement, in particular to a noise floor cancellation method based on a spectrum analyzer. Background technique [0002] When a general spectrum analyzer or receiver is used for small signal measurement, since the signal power is relatively close to the noise power within the resolution bandwidth, that is, the RBW bandwidth, the measurement of the signal power is affected by the noise power, and the measurement accuracy is reduced. [0003] In order to reduce the influence of noise signals, one of the more commonly used methods is to reduce the resolution bandwidth RBW. For single-tone signals, since the bandwidth of single-tone signals is quite small, the power concentration is not affected by the resolution bandwidth, so it is feasible to reduce the resolution bandwidth and the measurement process is rarely affected. For broadband signals, although the noise power in the band can...

AI Technical Summary

Problems solved by technology

For broadband signals, although the noise power in the band can be reduced, the signal-to-noise ratio can be improved, and the signal power can be measured more accurately by reducing the resolution bandwidth, but this method has a defect: that is, as the resolution bandwidth decreases , the number of sweep points increases, the sweep time will increase a lot, and the measurement efficiency will be greatly reduced

Images