Perforated Lightweight Broadband Metamaterial Absorber Based on 3-D Printed Honeycomb

This letter presents a broadband metamaterial absorber based on three-dimensional (3-D) printing technology. The proposed design comprises periodic arrays of honeycomb core as the constituent dielectric, onto which resistive paint has been deposited to realize broadband absorption. The novel feature of this structure is its perforated substrate geometry, which contributes to the mechanical strength and light-weight characteristics of the design. The structure also exhibits broadband absorption (greater than 90%) in a frequency range of 5.52-16.96 GHz under normal incidence, thus giving rise to a fractional bandwidth of 101.78%. An equivalent circuit model has been developed, and several parametric variations have been studied to analyze the absorption mechanism of the proposed geometry. The design has been fabricated using low-cost 3-D printing technology, and the resistive ink has been uniformly coated onto the substrate using screen printing technique. The prototype, while measured, shows reasonable agreement with the simulated response under normal incidence.