Additively Manufactured 3-D Printed Ultra Wideband Polarization Insensitive Absorber

This paper demonstrates a broadband absorber utilizing two layer three-dimensional (3-D) printing technology. In order to attain broadband absorption, a uniformly resistive paint is applied onto a set of rectangular annular strips and square annular rings positioned on a two-layer dielectric resonator in a swiss cross shape made of Poly Lactic Acid (PLA) substrate, which is mounted on the bottom layer also composed of PLA used as a dielectric material for 3-D printing. The absorber design showcases a broad absorption spectrum ranging from 5.9 to 19.17 GHz under normal incident conditions. This structure is not only lightweight but also possesses remarkable mechanical strength. Its fractional bandwidth reaches an impressive 105.86%. This absorber effectively sustains excellent and wide-ranging microwave absorption across incidence angles spanning from 0 to 45<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> for TE polarization, and from 0 to 65<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> for TM polarization leads a way to potential applications in C to Ku band.