Dispersion-reduced high impedance surface loaded with non-Foster impedances

A High impedance surface (HIS) supports surface waves, whose propagation constant k is associated with the reactive surface impedance. The frequency dependence of the surface impedance leads to dispersive surface wave propagation. This paper introduces a novel HIS loaded with non-Foster impedances whose special impedance-frequency relationship helps to reduce the dispersion of the surface wave propagation. The reduced dispersion is demonstrated with Eigenmode simulations, showing a constant refractive index over a significant broad bandwidth.