Enhanced transmission through truncated compound periodic arrays of subwavelength holes

Enhanced transmission through metal films perforated by single or arrayed subwavelength holes has been observed in the optical as well as in the microwave regime. In the microwave regime, the phenomenon is associated with dielectric slab guided waves and surface waves arising due to the periodic hole arrangements. A surface comprising rows of small holes interspaced by solid perfectly electrically conducting (PEC) strips, referred to as a two-period hole array (TPHA), was shown to be especially effective. Scattering from so-called compound TPHAs, comprising multiple finite TPHAs with different periodicities, is studied. The transmission properties of these structures are investigated for a wide range of problem parameters including the angle, polarization, and frequency of the incident field. It is shown that the signals transmitted through compound TPHAs contain features that are anticipated to render them useful in identification applications.