The fundamental parameters of the EMC (Electromagnetic Compatibility) antennas, which are used for EMC measurements, are the antenna correction factors, or simply the antenna factor (AF), and a related parameter, the transmit antenna factor (TAF), provides a clearer understanding of radiated emissions and immunity measurements.
This paper provides mathematical derivations of the antenna factors AF and TAF in terms of the effective length parameter (h). The antenna factors for dipole and loop antennas are then calculated and analyzed. A new procedure is suggested for obtaining the antenna factor and hence the gain (G) of Log Periodic Dipole Antennas (LPDA), which are used for emission and susceptibility testing. A simple technique is also devised to calculate the antenna factors for biconical antennas used in site attenuation measurements. The proposed procedures are then verified by comparing the calculated AF and G for different LPD and biconical antennas with their corresponding published data.