Design of Graded Photonic Crystals Antennas via Inverse Scattering based techniques

TL;DR

This paper introduces a novel inverse scattering-based methodology for designing graded Photonic Crystals antennas, enabling the creation of non-canonical devices with arbitrary far-field specifications.

Contribution

It develops two strategies for designing GPCs with graded refractive index and filling factor using inverse scattering and homogenization theories, advancing antenna synthesis techniques.

Findings

Successfully designed a reconfigurable ${ m extstylerac{ m ext{ extSigma}}}{ ext{ extDelta}}$ antenna

Validated the approach through numerical synthesis results

Enhanced flexibility in GPC antenna design

Abstract

A new approach to the design of graded Photonic Crystals (GPCs) devices is proposed by exploiting the inverse scattering framework as a synthesis tool. The introduced general methodology can be applied to arbitrary far-field specifications, thus allowing to design non-canonical devices. In particular, two different strategies are developed which allow to deal with GPCs with both graded refractive index (GPC_R) and graded filling factor (GPC_F). In both strategies, the inverse scattering problem is solved by a proper reformulation of the Contrast Source Inversion method wherein a proper rescaling of the amplitude of the primary sources is pursued. In particular, in the first one, the GPCs are obtained by exploiting homogenization theories. In the second one, the GPC_R profile is synthesized by exploiting a suitable representation basis for the unknown contrast function and, then, simple analytical formulas are used to determine a GPC_F. The proposed approach is assessed through the synthesis of an antenna generating ${\Sigma}/{\Delta}$ reconfigurable patterns.