Broadband Polarization-Insensitive Inkjet-Printed Conformal Metamaterial Absorber
Manish Mathew Tirkey, Nisha Gupta
Abstract
The objective of this article is to devise a cost-effective, conformal, polarization-insensitive, and broadband metamaterial absorber for X-band applications. A periodic subwavelength conducting grid pattern is printed over flexible papers in a multi-layered fashion to achieve the broadband behavior. A silver nanoparticle incorporated inkjet printing technique is employed that does not require any post-processing such as sintering. The absorber is eco-friendly and suitable for rapid mass production at a low-cost. Moreover, the printed patterns do not crack when bent or applied over curved surfaces. The characteristics, working principle, and equivalent circuit of the absorber are described. The absorber is designed on a 1.06 mm (0.03 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathbf {{\lambda} _{\it l}}$</tex-math></inline-formula> at the lowest working frequency) ultrathin substrate. It exhibits more than 90% absorptivity from 8.43 to 10.38 GHz for all angles of polarization with wide angular stability up to 45°. The flexibility and broadband feature is also confirmed by the experimental measurement of the fabricated prototype.