HORIZONTAL WIRE ANTENNA ABOVE LOSSY HALF-SPACE: SIMPLE ACCURATE IMAGE SOLUTION

A simple, approximate, but highly accurate, method is proposed for the analysis of horizontal thin-wire antennas above a lossy half-space. In the first step, the contribution of the lossy half-space to the field of a horizontal Hertzian dipole above the interface, both in the half-space above and in that below the interface, is approximated by the field of few (typically six) equivalent sources (images). The relative image intensities are obtained by enforcing the boundary conditions for the tangential components of the electric and magnetic field at a number of points at the interface. The field of the images is introduced into the Hallén equation; current distribution is approximated by polynomials and determined by point-matching. The results for the impedance of horizontal dipoles obtained by the present method are in excellent agreement with the exact results (obtained from the Sommerfeld theory), although the proposed method is conceptually much simpler and requires at least an order of magnitude less computing time than the exact method.