Circuit modeling of a diode-loaded dipole antenna

A circuit model for a diode-loaded dipole electric field measurement probe is developed which is valid for frequencies below 10 GHz. A nonnegligible dipole radius and the nonlinear characteristics of the diode are taken into consideration. The dipole lumped circuit elements and diode capacitances are determined by theoretical means while the diode V-I characteristics and resistance and determined by a combined theoretical and empirical approach. Newton´s iteration method is used to numerically solve the resulting nonlinear differential equation. Experimental measurements on a probe designed for operation between 1 and 1000 MHz and comparison with the theoretical results are presented. It is concluded that the accuracy of the proposed model is such that numerical data can be obtained for various designs of a diode-loaded dipole antenna and an optimum system can then be found for a particular application