Shortened Dipole Antenna Factors by the Reference Antenna Method at a Finite Separation

A shortened dipole antenna is widely used in electromagnetic compatibility measurements. The antenna factor (AF) of an antenna is usually calibrated by comparing the known AF of the reference antenna. Although the transmitting antenna is located at a finite separation, the effects of the E-field distribution along the receiving antenna element and the mutual coupling with the transmitting antenna are neglected. The neglect of them results in a considerable error since the element lengths of the shortened and the resonant reference antenna are considerably different at a low frequency. In the present paper, potential errors in implementing the reference antenna method for a shortened dipole antenna are discussed.