What does a spectrum analyzer do?

A spectrum analyzer is a specialized instrument used to visualize and analyze the frequency content of signals. Its primary function is to display the amplitude of signals across a range of frequencies, allowing engineers and technicians to assess the performance of different communication systems, identify interference, and conduct signal analysis.

By plotting the amplitude (vertical axis) against frequency (horizontal axis), users can quickly see which frequencies have the strongest signals and which are weaker. This capability is essential for tasks such as identifying unwanted noise sources, checking for compliance with frequency regulations, and optimizing the performance of transmission systems.

The other options, while related to signals and communications, do not describe the primary role of a spectrum analyzer. For example, recording audio signals is a function typically associated with audio recording devices, and strengthening weak signals pertains to signal amplification equipment. Converting analog signals to digital ones is a task performed by analog-to-digital converters, not spectrum analyzers.