Exact image method for field calculation in horizontally layered medium above a conducting ground plane

It is shown that the inverse Laplace transform of the Fourier domain reflection coefficient of a layered medium can be easily derived by performing the Mittag-Leffler expansion. Thus exact image theory can be used in field calculations. The radiation pattern is readily deduced from the image functions and the surface wave is also deduced from the field integrals. As applied to microstrip structures, the asymptotic approximations agree with the Sommerfeld formulas.