Spectrum Analysers

Types of Spectrum Analysers

Swept spectrum analysers: Sweeping the frequency that is analysed across the required band to produce a view of the signals with their relative strengths. Type that is most widely used.

Fast Fourier Transform, FFT analysers: Converting the signals into a digital format for analysis digitally. More expensive and specialised.

Real-time analysers: Form of FFT analyser. Requiring much larger buffers and more powerful processing, these types are able to offer the top performance in signal analysis.

Audio spectrum analyser: Focussed on audio frequencies, this means that low frequency techniques can be adopted. This makes them much cheaper. It is even possible to run them on PCs with a relatively small amount of hardware.

Spectrum analysers tend to fall into 4 form factors:

• Benchtop - can be plugged into AC power, which generally means in a lab environment or production/manufacturing area.
• Portable – can be taken outside to make measurements or simply carried while in use.
• Handheld - needs to be very light and small.
• Networked - ability to connect the analyser to a network

Spectrum Analyser Tips

• Beware input level: One major cause of damage is the input mixer being blown when the analyser is measuring high power circuits.
• Determine if spurs are real
• Wait for self-alignment: When first switched on, it goes through its software boot-up procedure and, undertakes a number of self-test and calibration routines.