Measurement of the antenna factor of diverse antennas using a modified standard site method

The standard site method given in ANSI C63.5-1988 is a convenient, widely used technique for determining the antenna factors of EMC testing antennas using open area test sites. The technique works well for dipoles and dipole-like antennas including broadband biconical antennas. However, for some types of antennas including some log-periodic dipole arrays as well as some new types of compact, broadband radiators, this technique can result in significant measurement error as given since the gain and phase patterns of the antennas are not taken into account. The method can give accurate results if it is modified to include both the gain and phase patterns of the antennas. Here we describe this new technique and then demonstrate the effect it has on the accuracy of antenna factor measurements.