Electromagnetic Fields of Hertzian Dipoles in Thin-Layered Media

Fast numerical methods are developed to compute the electromagnetic (EM) fields for thin-layered media for the entire distance range. Thin-layered media are defined to be the case when there are only surface wave modes but no leaky modes between the Sommerfeld integration path (SIP) and the vertical branch cut. Fields for distances larger than twice the layer thickness are computed by the numerical modified steepest-descent path (NMSP) method. The NMSP consists of integration along the branch cut with the pole proximity accounted for by using incomplete error functions. The fields for distances less than twice the layer thickness are computed by the first two orders of low-frequency approximation up to frequency squared. These two methods are used to compute the electromagnetic fields for all distance ranges. The CPU per point is of the order of milliseconds using a Pentium IV 3.2 GHz CPU and Matlab. The CPU for each point as a function of distance range is tabulated