How Does A Spectrum Analyzer Work?

A spectrum analyzer or spectral analyzer is a type of electrical test equipment that allows you to measure an electrical, optical or acoustic waveform. A spectrum analyzer displays the frequency response curve in real time. A spectrum analyzer can also measure the power spectrum or power density when used in conjunction with a calibrated antenna.

There are two types of spectrum analyzers, analog and digital. Analog spectrum analyzers come in two types. One type works by using a variable band-pass filter whose mid-frequency is swept through the range of frequencies which you wish to measure in the spectrum. The other type makes use of a superheterodyne receiver where an oscillator is swept through the range of frequencies you're measuring. A digital spectrum analyzer works by computing the discrete Fourier transform (DFT). The DFT is a mathematical formula which transforms a waveform into the components of its frequency spectrum. Due to various strengths of digital technology an analog spectrum analyzer cannot outperform a digital spectrum analyzer as regards frequency resolution for a given acquisition time.

A few spectrum analyzers use a method of measurement which is a hybrid of both the analog and digital techniques. In these types of analyzers the incoming signal is initially down-converted to a lower frequency using superheterodyne techniques and then analyzed using fast fourier transformation (FFT) techniques.

Spectrum analysis instruments are utilized in a multitude of fields for a broad variety of signal analysis purposes. The telecommunications industry uses spectrum analyzers to determine occupied bandwidth and track sources of RF interference. They are also routinely used in the electronics field and related industries to perform distortion and noise analysis on several different types of signals. In addition they are also used extensively in the audio and acoustic industries for measuring frequency response. High end audio and home theater installations can benefit greatly from being checked out with a spectrum analyzer in order to see which frequencies are being altered because of the room physics. Once the frequency analysis is complete the affected frequencies can be boosted or cut as necessary with an equalizer in order to achieve a flat response.

Some of the most prominent manufacturers of spectrum analyzers are Tektronix, Agilent and Rohde & Schwarz. We invite you to check out all of the new and used spectrum analyzers below that are currently available for purchase. Browse the selection of new and used spectrum analyzers that we have available for sale through our affiliation with eBay - you won't find better prices anywhere else! If you don't see what need, search here to perform a more extensive search.