Chlorophyll-Inspired Tunable Metamaterials With Multi-Negative Refractive Index Bands: The Porphyrin Ring and Hydrophobic Tail Effect

Abstract

Tunable negative electromagnetic properties: permittivity, permeability, and refractive index, in mimic Chlorophyll metamaterial structures in the X-and Ku-band regimes are theoretically and numerically demonstrated. A very broad negative permeability covering the majority of the X-and Ku bands, from 8 GHz to 16 GHz, is observed, while five negative permittivity bands are found within the same range. The two aforementioned properties result in a broad, greater than 25% bandwidth, low-loss negative-refractive index transmission band. These negative electromagnetic properties can be effectively tailored within the low-loss multi-transmission and the high-loss multi-absorption bands in the operating frequency range by modifying the structure's tiller part or the artificial hydrophobic or Phytol tail. By focusing either on the transmission or the absorption bands, these passive always-on bio-inspired metamaterials could be utilized in microelectronic, communication and photonic, and optic devices.