I. Introduction
A perfect magnetic conductor (PMC) surface is an ideal high-impedance surface. It has infinite impedance meaning that the mirror currents of horizontal electrical currents are not phase shifted. This is desired for low profile antennas as ordinary planar antenna elements can be put on top of a PMC without loss of performance [1], [2]. However, PMCs are artificial surfaces typically synthesized from periodic structures above an ordinary ground plane [1]–[3]. The properties of the artificial high-impedance surface depend on frequency, polarization, and angle of incidence, and they have high impedance only over finite frequency bands [1], [2].