Spectrum analyzers are instruments that is used to receive and select frequency levels based on the superheterodyne principle. It is very sensitive, converting higher frequencies of up to 10s GHZ into something that is measurable. Received frequencies are first put into a series of pre-selected values.

These are then converted into a frequency that is selected to a DC level that is measurable. Often the values are converted into the logarithmic scales. These values are then displayed in the CRT, with the signal strength in the y-axis and the frequency in the x-axis.

Signals that are weaker than the noise in the background cannot be measured by the spectrum analyzer, power levels that are often seen in microwave receivers. This is the reason why spectrum analyzers need the RBW to be able to determine these measurements. Here, the received signals are measured in decibels rather than voltage because of the low signal strengths that are received and the frequency range of the measurements.

Spectrum analyzers especially the modern ones have a lot of uses. One of which is as a device frequency response measurements, which is used primarily in measuring amplitude response in dBm in comparison to the frequency of the device. The resulting value is on Hertz.

Another use is as a microwave tower monitor, where its transmitted power and receiver power is measured. This is one way to verify the strength and frequency of the signal.

Spectrum analyzers are also being used to identify and measure interference in signals, which are often needed in site operations of telecom towers, TV stations and the guiding systems of airports.

It can also provide measurements that are specific to the program or applications being used such as in the case of Adjacent channel power or (ACP) and phase noise. It can also analyze digital modulation measurements especially against industry standards such as GSM and blue-tooth. Another application is the analysis of vector signals as well as the saving, printing and transferring of data.

Spectrum analyzers also allow you to have remote control over LAN and the Internet as well as update firmware, add new features and fix problems in the program. Some spectrum analyzers also have provisions for diagnostics and self-calibration.

Other measurements that the device can handle are measurements of return and loss as well as spurious signals; and alignment of satellite antenna