Which of the following is used to determine if an antenna is resonant at the desired operating frequency?

An antenna analyzer is a highly versatile piece of test equipment specifically designed for tuning and troubleshooting antennas. It contains its own low-power signal generator and impedance-measuring circuitry to sweep across a range of radio frequencies. By connecting an antenna to the analyzer, you can quickly see the antenna's Standing Wave Ratio (SWR) and impedance profile, which instantly reveals the exact frequency where the antenna is naturally resonant. The distractors are incorrect because a frequency counter only counts the cycles of an active external signal, a VTVM measures basic voltage, and a Q meter measures the quality factor of individual components. None of these are used to sweep an antenna system to find its resonance.