All You Need to Know About Spectrum Analyzers

Introduction: All You Need to Know About Spectrum Analyzers

About: I’m Lisa Clark from Madison, Wisconsin, and have been working as product & test engineer for the past 3 years.

A spectrum analyzer is a device used to determine the various facets of an electronic signal. Spectrum analyzers differ from oscilloscopes because oscilloscopes measure amplitude as a function of time, as opposed to spectrum analyzers, that measure amplitude as a function of frequency. The spectrum analyzer is used for a variety of functions such as isolating particular signals, unknown signal detection, frequency and amplitude measurement, and measurement of total signal energy.

There are three popular types of spectrum analyzers used around the world. First off, the analog analyzer, which measures frequency through the use of a band pass filter. Digital analyzers are widely available too, and these use a DFT or Discrete Fourier Transfer to detect frequency. Lastly, hybrid spectrum analyzers use Fast Fourier Transform (FTT) to calculate signal strength, and super heterodyne for signal interpretation.

The spectrum analyzers functions in detail

Step 1: Frequency and Amplitude Measurement

A typical electric signal contains a variety of concurrent waveforms of varying amplitudes, frequencies and phases. It is the task of a spectrum analyzer to distinguish a signal into its various frequencies and amplitudes. The results are then depicted on a graph with the X-axis typically illustrating frequency on the X-axis and the Y-axis, amplitude.

Step 2: Isolating Signals

Another function of the spectrum analyzer is the ability to separate a particular signal from the background. This is done by adjusting the sample to specific frequencies. Because of this, a low-amplitude signal can be studied separately from its corresponding high-amplitude signals of varying frequencies.

Step 3: Unknown Signal Detection

The functionality of a spectrum analyzer doesn't end once it is used to determine the standard, or baseline signal range. After this is done, it can be used to check if signals exist that fall out of this baseline range, allowing detection of signals of potential harm or belonging to an external source.

Step 4: Measurement of Total Signal Energy

Safety is an important aspect of any workplace dynamic, and spectrum analyzers provide support in this regard too. Because spectrum analyzershave total signal energy measurement capabilities, they can be used to measure energy levels and make sure that they don’t a exceed a point where they can cause equipment failure or risk injury to individuals handling said equipment.

Step 5: Some Real World Applications of Spectrum Analyzers

  1. Telecom: Mobile phone service providers use spectrum analyzers to detect interference in their lines and pinpoint regions that are suffering from weak network signals as well.
  2. Forensic Studies: Forensic analysts often times rely on voice identification to help determine which individuals are involved when video evidence is lacking or insufficient. A spectrum analyzer is used to isolate an individual’s by measuring his or her speech pattern, and identifications are also made by detecting pitch changes for a set of particular words, changes that are close to unique for each individual.
  3. Analysis of a Radio Frequency (RF) Environment in a Specific Location: If a commercial RF environment has been established, a spectrum analyzer helps detect anomalies in the frequency, allowing for optimal service provision and troubleshooting solutions.

While the market to buy spectrum analyzers and even rent spectrum analyzers is widely known of, there is also booming trade for parts and accessories associated with spectrum analyzers. As is illustrated on the TRS-RenTelco website, a testing equipment sale and rental establishment, associated articles such as antenna kits, delay lines and extension cables, among others are also available to maintain the upkeep of spectrum analyzers.

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    7 years ago on Introduction

    I've used a lot of different osscilloscopes in my day but never a spectrum analyzer. Great information!