A method and apparatus for calibrating an antenna apparatus and testing an antenna connected thereto is provided. The calibration is conducted without an antenna connected to establish a baseline return loss calibration coefficient. Thereafter, after an antenna is connected, a test may be conducted to measure the performance of the antenna on the antenna site apparatus. The calibration process includes measuring a leakage signal, measuring an average of the magnitude of a ripple output of the reflection signal over a frequency range to determine the baseline return loss calibration. Thereafter, if the antenna is connected and the test signal is again swept over frequency, then a new ripple factor is determined for the antenna and a new mean output voltage for Vant is determined. By comparing the new average output voltage for Vant and the baseline return loss calibration, one can determine information about the performance of the antenna.