Characteristics of the skeletal biconical antenna as used for EMC applications

The Numerical Electromagnetics Code (NEC) is used to simulate the radiators of a skeletal biconical antenna and the model is optimized to return a drive point impedance as close as possible to measured values. The horizontally polarized model is then illuminated in free space and above a ground plane to deduce its plane-wave antenna factors and their variations as functions of height. It is shown that changes in effective length have to be considered in addition to changes in impedance mismatch when calculating antenna factor variations with the biconical antenna, although only the latter are necessary with a resonant dipole. The measured scattering parameters of the balun of the biconical antenna are then incorporated with the NEC simulation to give a complete model of the real antenna