A comparison between two alternative procedures for calibration of EMC antennas per ANSI 63.5

The adequacy of the measurement methodology of the three antenna method of ANSI Standard C63.5 is addressed. The transmit receive pairing of the three antennas, as required in the standard, where one of the antennas is not used to transmit, has been challenged as not providing the most accurate answers. Instead, an alternative pairing has been proposed where all three antennas both transmit and receive. The authors describe a series of measurements that addresses the difference in the standard and proposed measurement methodologies, and determines if a change is needed in the measurement standard. It is found that the measurement methodology of ANSI 63.5 and the measurement methodology proposed as an alternative, where each antenna is used for both transmission and reception, provide virtually identical results. It is concluded that no changes in the methodology of the ANSI standard three antenna method of measuring antenna factors are required