Numerical analysis of cylindrical dipole antennas using an auxiliary sources model

Abstract

In this paper, the problem of the radiation from a circular cylindrical dipole antenna, which is either symmetrically or asymmetrically fed by an idealized voltage source, is analyzed using the method of auxiliary sources (MAS). This method is applied by introducing a set of fictitious sources carrying unknown currents inside the dipole for the direct description of the radiated electromagnetic (EM) field. The unknown currents are determined by imposing the electric field continuity boundary conditions on the physical surface of the dipole. The solution is formed using spatially overlapped small sinusoidal dipoles, instead of elementary dipoles that are usually used in conventional implementations of current‐model based techniques. It is shown that this choice leads to a significant acceleration in the rate of convergence of the solution and, as a direct outcome, to a noteworthy reduction of the relevant computational cost. Since the currents of the fictitious sources are determined, various quantities of great theoretical and practical interest, are readily computable. Several examples illustrating the well‐behaved convergence of the proposed method are presented, concerning various geometrical configurations. In each case, the accuracy of the resultant solution is verified by checking the stability of the input impedance/admittance of the dipole for an increasing number of fictitious sources and comparing the computed values with previously published data.