Spectrum Analyzers

It should be noted from the onset that there are many different types of spectrum analyzers. In general, spectrum analyzers are those devices that are used to examine the spectral composition of some electrical, acoustic, or optical waveform. There are RF and EMF devices as well as other types that measure other spectrums.

For the most part, these devices will return a result that is within the power spectrum. In other words, how strong or how weak a particular spectrum is at any given time.

There are analog and digital spectrum analyzers:

An analog spectrum analyzer uses either a variable bandpass filter whose mid-frequency is automatically tuned through the range of frequencies of which the spectrum is to be measured or it may use a super-heterodyne receiver where the local oscillator is swept through a range of frequencies.

A digital spectrum analyzer computes the Fast Fourier Transform (FFT). This is a mathematical process that transforms a waveform into the components of its frequency spectrum and returns that computation back to the user in digital form.

Two of the most popular types of spectrum analyzers are RF and EMF devices. The RF type searches through the radio frequencies and the EMF types measure Electro-Magnetic Fields. These types of measurements are important in many kinds of applications both commercial and for the hobbyist.

Because spectrum analyzers are so diverse, it should be no surprise that the price ranges for these devices is diverse as well. For hobbyists or those on a strict budget, kits can be purchased and the devices made at home or in the workshop. Then there are the high-end models that can cost tens of thousands of dollars. There are a myriad of models in between the two as well.

Before choosing spectrum analyzers make sure that you understand exactly what it is that you need the device to do. Some of the low end models may not be sensitive enough to measure all of the variables or frequencies that you may need it to measure. For this reason it is always a good idea to read the product information literature before you buy.

The above is especially important if you are planning to buy RF spectrum analyzers. You should have some idea of the range that you will be testing so that you can ensure that the device you are interested in will be adequate. Not all spectrum analyzers are equal in quality or sensitivity.