spectrum analyzer

A device that effectively performs a Fourier transform and displays the individual spectral components (sine waves) that constitute a time-domain signal.

spurious response

The undesired responses that appear on an analyzer display as a result of the input signal. Internally generated distortion products are spurious responses, as are image and multiple responses. These can be either harmonic responses or nonharmonic responses. Harmonic responses are second, third, fourth, and so on, harmonics of the input signal. Nonharmonic responses are intermodulation and residual responses.

state-register

The area of user memory in the analyzer where measurement results and associated analyzer settings are stored.

step

The increment of change that results when you press the front-panel step keys, (3-J and 0, or by program commands.

stimulus-response mode

The operating state that allows an analyzer to make measurements similar to those of a network-analysis measurement system. Analyzers with this ability use tracking generator functions. The tracking generator may be an external instrument (stand-alone tracking generators) or designed into the analyzer hardware. Measurement results are displayed in a relative-amplitude scale resulting from a variation, plus or minus, from a reference (normalized) value stored in a trace.

stop/start frequency

Terms used in association with the stop and start points of the frequency measurement range. Together they determine the span of the measurement range.

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