Spectrum measurements are invaluable in the laboratory to evaluate the signal characteristics of a new design, and in the field to monitor known signals and search for interference. To make such measurements, engineers have typically turned to the RF/microwave spectrum analyzer. It is widely available in benchtop and portable varieties, and even in compact-module form with a USB interface that can add a PC’s functionality and display screen to the instrument package.
However, instruments known as “signal analyzers” have also become available in recent years, with somewhat different capabilities and intended applications, including electromagnetic-compatibility (EMC) compliance testing and examining signals with complex modulation. The cost of these signal analyzers is higher than a traditional spectrum analyzer, so it helps to know when it makes sense to specify an RF/microwave signal analyzer rather than a spectrum analyzer.