Which device detects and analyzes RF spectrum?

• A. Multimeter
• B. Shows signal strength
• C. Detects and analyzes RF spectrum
• D. Tool that measures percentage of bits received incorrectly

Answer: (C)

A spectrum analyzer is the instrument used to detect and analyze RF spectrum. It measures how signal power is distributed across frequencies, giving you a visual display of which frequencies are active, their power levels, and the bandwidth of each signal. This lets you see carriers, interference, harmonics, and the overall spectral occupancy of a band, which is essential for tasks like tuning, interference mitigation, and validating communications links.

This is broader than a basic multimeter, which only measures electrical quantities like voltage, current, and resistance and doesn’t provide information about how those signals are spread across frequency. It’s also more capable than a simple readout of signal strength, which might tell you how strong a signal is at one point but won’t show the full frequency spectrum. And it isn’t about data integrity or error rates; devices for that purpose measure how many bits are received correctly, not how the spectrum looks.

So, a spectrum analyzer directly fits the idea of detecting and analyzing RF spectrum because it reveals the entire frequency-domain content of signals, not just a single metric or a single channel.