The input impedance of a monopole antenna mounted on a cubical conducting box

An experimental investigation has been performed to determine the input admittance characteristics of a monopole antenna mounted on a conducting cubical box over a ground plane. Input admittances of monopoles from 2 to 6 cm long mounted on a 10 cm box were considered in the investigation so that effects of changes in the electrical size of the box could be evaluated. The monopoles were placed at various points to determine the functional dependence of input admittance on the position of the monopole antenna. A numerical analysis of the radiating structure was performed using the method of moments to compare the experimental data with the computed input admittance. This comparison and the observed empirical behavior of the input admittance were then utilized to predict the effects of the conducting box on the overall admittance of the radiator.