Ultrabroadband Absorber Based on Layered Inkjet-Printing Resistive Film

This letter proposes an ultrabroadband absorber (UBA) based on the layered inkjet-printing resistive film (IPRF) composed of three lossy layers. The equivalent circuit model of the UBA is put forward to analyze the impedance matching with air under broadband conditions. The prototype was fabricated using IPRF as the lossy layers and the polymethacrylimide (PMI) foam as the dielectric layers. The simulated and measured results show that the ultrabroadband 0 dB absorption performance covers 2–23 GHz with the fractional bandwidth of 168% and maintains stable absorbing performance under the incidence angle of 45°. The total thickness of the proposed design is only 0.1
λ_L
at the lowest operating frequency. Experimental validation of the fabricated prototype has also confirmed the potential using of IPRF-based broadband absorbers in several applications.