Two-dimensional image method for time-harmonic line current in front of a material cylinder

The well-known electrostatic two-dimensional image theory involving a line charge parallel to a dielectric cylinder is extended to the electromagnetic problem where the source is a time-harmonic current and the permittivity a nd permeability of the cylinder may be different from those of the exterior space. The reflection and transmission images of the current line giving t he field reflected from the cylinder and the field transmitted into the cyl inder are presented in the form of cylindrical surface currents obeying exp licit series expressions. It is shown that by choosing the image cylinders properly and extracting a line image source from each, the convergence of t he series can be dramatically improved. The reflection image is seen to red uce to a double-line image on the axis when the distance of the line curren t from the surface of the cylinder becomes infinitely large.