The development of an optimal NEC model of a skeletal biconical antenna for use with antenna factor prediction

A useful development of the modelling approach to antenna calibration is to accept that it is not practical to measure antenna factors directly and instead compare values of another antenna parameter, which can be measured accurately, with predictions derived from a model. One such parameter is drive-point impedance and, if a model can be developed which returns a drive-point impedance that agrees with measurement, the model may then be used with confidence to predict antenna factors. The paper shows how the drive-point impedance of a Schwarzbeck BBA9106 biconical antenna may be measured and then used as a guide to facilitate production of an accurate NEC model of the antenna. This model is then combined with the measured scattering parameters of the balun of the antenna in order to yield predicted antenna factors for the complete real antenna