A Comparison of Three Techniques for Evaluating the Vector Potential of a Vertical Current Element Radiating Over the Lossy Half-Space

A comparison is made of the three techniques for evaluating the vector potential arising in the pro­ blem of a vertical current element radiating over a lossy half-space: 1) the exact Sommerfeld integration, 2) the reflection coefficient method (RCM) ,and 3) the high contrast approximation (HCA) .The advantage of both approximate techniques, RCM and HCA, is that they circumvent the need for computing the Sommerfeld inte­ gral. The results of the analysis indicate that HCA yields acceptable results when the significant distan­ ce of the problem (the distance between the image and the field points ) is extremely small, i.e. in the sit­ uation when the RCM fails. It is concluded that the RCM and HCA complement each other over a relatively wide range of parameters of practical interest.