Spectrum Analyser
A spectrum analyser is a piece of equipment that is used during EMC measurements. It's primary purpose is to measure the amplitude of individual frequencies that are contained in a RF signal. This RF signal is very often an electromagnetic field that is received by an antenna.
RadiMation has divided spectrum analysers in three different classes:
- Spectrum analyser
- Scanning receiver
- Receiver
- FFT (Time-domain) analyser
Receiver[edit]
A receiver is only measuring a single RF frequency. The receiver itself is not able to measure multiple frequencies. If more than one frequency need to be measured a PC has to change the selected frequency on the receiver, before a new measurement is performed.
Scanning receiver[edit]
A scanning receiver is a more intelligent receiver, which is able to step through a frequency range on it's own, so multiple frequencies can be measured automatically. A PC that is controlling the scanning receiver can instruct the scanning receiver to measure a certain frequency range. The scanning receiver will then return the data of the all the measured frequencies after (or during) the measurement is finished.
A scanning receiver is always measuring on all and the exact frequencies that are specified by the start-, stop- and step-frequency.
Spectrum analyser[edit]
A spectrum analyser is a measuring device that sweeps in a short time along the frequency range that should be measured. During this sweep all frequencies are measured, and a PC can retrieve a list of the measured amplitudes from the spectrum analyser. The list of measured amplitudes is often a reduced list of a specific amount of frequencies (401 points, 601 points, etc...)
FFT analyser[edit]
An FFT analyzer is a device that processes signals in the time domain and transforms them into the frequency domain using the Fast Fourier Transform algorithm. Unlike a spectrum analyzer, which sweeps across a frequency range, an FFT analyzer captures a signal’s entire frequency content all at once, over a specified bandwidth.
Common[edit]
Most scanning receivers and spectrum analysers include a lot of functionality to make it easier for an end-user to perform certain measurements. This additional functionality can be:
- EMC Overview measurements
- Completely automated EMC measurements including peak detection and peak measurements
- telecommunication measurements
Spectrum analysers are always used during Emission tests. In some situations a spectrum analyser is also used during immunity tests, mainly to measure a RF signal.
All the device drivers for spectrum analysers maintain the following information:
- Allowed frequency range
- if the device is a receiver / scanning receiver / spectrum analyser
- Instructions on how to
- Set start-, stop-, center-, span- and step-frequency
- change RBW settings
- change Reference level settings
- change Attenuation settings
- change VBW settings
- change preselector settings
- change preamplifier settings
- change measure time settings
- change sweep time settings
- change detector settings
A complete list of all supported spectrum analysers by RadiMation is available on this RadiWiki site.
Links[edit]
- Wikipedia: Spectrum analyser