What does the Zero Span function on a spectrum analyzer provide?

The Zero Span function on a spectrum analyzer allows for an amplitude versus time display at a specific frequency. When the spectrum analyzer is set to Zero Span, it effectively becomes a time-domain measurement tool rather than displaying frequency-based information. This function "freezes" the frequency domain, allowing the user to monitor signal variations over time at a designated frequency.

In practical terms, this means that instead of observing how amplitude varies across a spectrum of frequencies, the user can analyze how the amplitude of a signal changes over time for a fixed frequency. This is particularly useful for capturing transient signals or analyzing modulation characteristics of signals that only occur at one frequency.

Other options describe different capabilities of a spectrum analyzer, but they do not pertain directly to the Zero Span function. Continuous amplitude vs. frequency display relates to sweeping the entire frequency range, while peak signal strength measurements involve determining the maximum amplitude at various frequencies. Quick frequency sweeps pertain to measuring across a range of frequencies rather than focusing solely on a single one over time.