Analysis and Synthesis of Cascaded Cylindrical Metasurfaces Using a Wave Matrix Approach

Abstract

In recent years, there has been extensive research on planar metasurfaces capable of arbitrarily controlling scattered fields. However, rigorous studies on conformal metasurfaces, such as those that are cylindrical, have been few in number likely due to their more complex geometry. Here, wave propagation in cascaded cylindrical structures consisting of layers of dielectric spacers and azimuthally-varying metasurfaces (subwavelength patterned metallic claddings) is investigated. A wave matrix approach, which incorporates the advantages of both ABCD matrices and scattering matrices (S matrices), is adopted. Wave matrices are used to model the higher order coupling between metasurface layers, overcoming fabrication difficulties associated with previous works. The proposed framework provides an efficient approach to synthesize the inhomogeneous sheet admittances that realize a desired cylindrical field transformation. Design examples are reported to illustrate the power and potential applications of the proposed method in antenna design and stealth technology.

A Rigorous Approach to Designing Reflectarrays

“…Metasurfaces conformal to different shaped surfaces have also seen interest in recent scientific works. Consider the work in [107]. By formulating the wave matrix synthesis approach of section III.C in terms of cylindrical modes, the same approach can be used to synthesize cascaded cylindrical metasurfaces.…”

“…There are 32 entries in the scattering matrix but if one applies lossless and reciprocal constraints, there are only 10 distinct entries of the scattering matrix. These 10 distinct entries can be realized using 4 sheets, since each sheet can provide 3 entries [107]. Therefore, three sheets are insufficient if one is to realize a full scattering matrix.…”