Hints for improved spectrum analysis

Superheterodyne means to mix or to translate in a frequency above audio frequencies. In the analyser, a signal at the input travels through an attenuator to limit the amplitude of the signal at the mixer, and then through a low-pass input filter to eliminate undesirable frequencies.

When digital technology first became viable, it was used to digitise the video signal. As digital technology has advanced over the years, the spectrum analyser has evolved to incorporate digital signal processing (DSP) to be able to measure signal formats that are becoming increasingly complex. DSP is performed to provide improved dynamic range, faster sweep speed and better accuracy.

To get better spectrum analyser measurements the input signal must be undistorted, the spectrum analyser settings must be wisely set for application-specific measurements, and the measurement procedure optimised to take best advantage of the specifications. This application note from Agilent Technologies provides more details on these steps.

View the PDF document for more information.