Corrugated Surfaces With Tailorable Dark Sectors Within Prescribed Frequency Bands

Electromagnetic bandgap (EBG) surfaces have customarily been defined as being prohibitive of surface-waves within frequency ranges called bandgaps, for all directions along the surface, this latter specification being an understood presumed condition. However, not all practical applications require such an entire bandgap in terms of surface directions. Rather, there could be situations where surface-wave suppression is needed along directions only within an angular sector but are instead desirable towards others outside, over a frequency band, termed herein as a sectoral dark band (SDB). This work investigates this aspect using planar corrugated surfaces as the vehicle for study, in virtue of its ease of surface-wave modal analysis of dispersion by asymptotic corrugations boundary conditions (ACBC). A systematic design procedure for tailoring surfaces to any specified dark sector of weak signals prevailing over any prescribed band is presented.