Modified Wheeler cap method for measurement of antenna efficiency

A new non-circuit model method to predict the antenna efficiency via means of Wheeler cap measurements is proposed. The method uses an interpolated prediction of the quality factor of the antenna in the radiating and non-radiating modes with the help of Wheeler caps. The method works for narrow, multiple, and wide band antennas with a complete immunity to the effect of the cavity modes. Also, the semi-analytical approach in dealing with the reflection coefficient embraces an insightful view to individual resonators in the measurements. The proposed procedure provides a simpler, more accurate, and straight forward method to measure the antenna efficiency than other Wheeler cap based alternatives. The results of the proposed methods are verified with a commercial full wave solver and measurements.