Time-harmonic point charges in layered media and their use in microstrip antenna calculations

Sommerfeld´s choice for potentials is (A, /sub x/0, A/sub z/) for an x-directed source and (0, 0, A/sub z/) for a z-directed source. For two dielectric half-spaces, this choice yields two different values for the scalar potential of a point charge, depending on the direction of the current to which the charge belongs. The authors establish a relationship between these two scalar potentials for a general layered medium, and examine the effect of these potentials on a practical quantity like the input impedance of a microstrip antenna. The problem of a horizontal dipole and a vertical filament is treated and applied to the case where the filament represents a coaxial probe feeding a microstrip patch.<>