Spectrum analyzers are used to display the spectral characteristics of input signals in the frequency domain. Spectrum analyzers are used to analyze and study signals in the frequency domain and are used in many different fields, such as wireless signal transceivers, signal interference detection, spectrum monitoring, and component characterization, etc. It is a common tool for R&D, production, and inspection of electronic products, and is an essential tool for wireless communication signal measurement. Its application range is very wide, so some engineers will also call it a universal meter for RF measurement.

Spectrum analyzer is divided into real-time analysis type and sweep class. The former can obtain all the required spectrum information and analyze and display the analysis results within the actual time of the measured signal; the latter needs to complete the analysis of repeated information through multiple sampling process. Real-time spectrum analyzer is mainly used for non-repetitive, very short duration signal analysis. Non-real-time spectrum analyzer is mainly used for the analysis of a certain continuous RF signal and periodic signal from the acoustic frequency until the sub-millimeter band.