Spectrum analysis theory revolves around the mathematical and conceptual frameworks used to analyze signals in the frequency domain. It encompasses the principles of Fourier analysis and signal processing, where signals are broken down into their constituent frequency components.

This decomposition allows analysts to study and understand the spectral characteristics of signals, such as their frequency distribution, amplitudes of various frequency components, and spectral density.

In the context of the question, “Spectrum of theory” generally refers to the range or scope of concepts and applications covered by spectrum analysis theory. It includes various techniques and methodologies for analyzing signals in the frequency domain, ranging from basic Fourier transforms to advanced spectral estimation methods.

The spectrum of the theory thus encompasses a wide range of applications in different fields, including telecommunications, audio engineering, radar systems and scientific research.

In the context of analysis, “spectrum” refers to the distribution of frequencies present in a signal or system. It describes the range of frequencies over which a signal or system operates or is analyzed. Spectrum analysis can refer to the frequency spectrum of a signal, where the amplitude of each frequency component is plotted against its frequency.

It may also refer more broadly to the range or variety of components, characteristics, or aspects examined in a specific analytical context, such as in the spectral analysis of signals or systems