Spectrum analyzer can be divided into two types: sweep frequency spectrum analyzer and real-time analysis spectrum analyzer. Spectrum analyzer is a instrument of electrical signal spectrum structure, used for signal distortion, modulation, spectral purity and frequency stability degree and intermodulation distortion and signal parameters measurement, available to some parameters of the measuring amplifier and filter circuit system, is a multi-purpose electronic measuring instruments.
It can also be called frequency domain oscilloscope, tracking oscilloscope, analytical oscilloscope, harmonic analyze, etc.. The modern spectrum analyzer can display the analysis results in analog or digital way, and it can analyze the radio signal of the whole radio frequency range of 1 Hz to sub millimeter wave band. If a digital circuit and a microprocessor are used in the instrument, it is easy to form an automatic test system with the function of storing and computing.