Spectrum analyzer

A spectrum analyzer is a device used to examine the spectral composition of some electrical, acoustic, or optical waveform.

Often, it measures the power spectrum.

There are analogue and digital spectrum analyzers:

• An analogue spectrum analyzer uses either a variable bandpass filter whose mid-frequency is automatically tuned (shifted, swept) through the range of frequencies of which the spectrum is to be measured or a superheterodyne receiver where the local oscillator is swept through a range of frequencies.
• A digital spectrum analyzer uses the Fast Fourier Transform (FFT), a mathematical process that transforms a waveform into its frequency components in the spectrum. As a result, computer programs can compute such transforms, and makes audio processing easier. FFTs have applications in much wider fields.

See also

• electromagnetic spectrum
• spectrum
• spectrogram

Non-electronic spectrum analyzers

Used to measure atomic particles.