A Multi-band Textile-Based MTM Absorber for Energy Harvesting Applications

This paper is devoted to design and implementation of multi-band textile based Metamaterial absorber operating at K and Ku bands to be deployed in energy harvesting system. The unit cell of the absorber comprises a ground plane of copper annealed, Felt textile and top ground layer with etched Jerusalem cross surrounded with etched square ring. It provides three highly resonant peaks at 16.7 GHz, 18.6GHz, and 22.45 GHz, with absorption percentages of 99.8%, 96.5%, and 99.7%, respectively. The full width at half maximum (FWHM) is 3.35 GHz (19%) at 17.6 GHz. In addition, the absorber provides a wideband of absorption for oblique incidence up to 20 degrees and also at different bending radii. The relative permittivity and permeability are studied to demonstrate it effect on the absorption mechanism. A negative index of refraction is achieved over a band of 6.5 GHz from 16 GHz to 22.5 GHz, which leads to perfect absorptivity.