Systematic and Accurate Method to Model Dielectric Stratifications in Artificial Dielectric Layers

We present a systematic approach to include the effects of dielectric slabs in artificial dielectric layers (ADLs). Typical implementations of ADLs consist of layers of subwavelength metal patches supported by either dielectric slabs or thin dielectric films bonded onto foam spacers. The presence of dielectrics in the proximity of the metal layers affects the equivalent layer capacitance and thus must be accurately taken into account for the modeling and design of the ADLs. The proposed procedure allows to derive an analytical expression for the effective permittivity of each capacitive layer that depends on the dielectric layers in the vicinity of the metal. The equivalent layer capacitance can then be included in the ADL equivalent transmission line model, which can be used, for instance, for the design of matching structures in ultrawideband arrays.