Abstract: Over the last couple of decades, different types of spectrum analyser were developed for numerous applications in various fields, such as, measurement of spectral purity of multiplex signals, percentage of modulation of AM signals, and FM modulation characteristics and pulse-modulated signals. The spectrum analyser is also used to interpret the demonstrated spectra of pulsed RF radiated from a radar transmitter. A spectrum analyser is the primary tool used for studying the spectral anatomy of numerous electrical and optical waveforms. The present day’s spectrum analyser is a vital portion of the engineer's toolbox. Which is used for the demonstrations of a power spectrum over a given frequency range, altering the display as the assets of the signal modification. Here, we present the basic idea around how the spectrum analyser works in a different environment, how it is efficient as compared to other type of measuring instruments and all additional characteristics of the spectrum analyser. In the presence of many signals, monitoring is very complicated to determine the performance of a system or device. The major components of spectrum analyser and how it is used during analysing the performance of devices.
Keywords: Signal, Spectrum, Period gram, Fast Fourier Transform (FFT).