THE FIELD OF AN ELECTRIC DIPOLE AND THE POLARIZABILITY OF A CONDUCTING OBJECT EMBEDDED IN THE INTERFACE BETWEEN DIELECTRIC MATERIALS

In this paper, a study is made of the electrostatic potential and fleld of an electric dipole located in the interface between two dielectric regions. When the dipole is oriented perpendicular to the interface, the detailed position of the charges of the dipole relative to the location of the interface has a signiflcant efiect on the value of the fleld produced away from the dipole, unlike the case of a dipole parallel to the interface. It is shown that it is the total dipole moment (due to both free and bound charges), rather than simply the impressed (free) dipole moment that is important in determining the fleld in this case. Based on these results, the question of deflning and determining the electric polarizability of a perfectly conducting object partially embedded in a dielectric interface is examined. The example of a conducting sphere embedded halfway in the interface is studied as a demonstration of our general formulation. The results of this paper are important for the proper modeling of arrays of scatterers embedded in an interface, such as frequency-selective surfaces (FSSs) and metafllms.