Ultra-Wideband Metamaterial Absorber Using Slotted Standing-Up Lattice Array

The emphasis on achieving wideband absorption often results in complex metamaterial designs that substantially increase manufacturing costs and time. To address this challenge, a simple vertical-slot strategy has been proposed for ultra-wideband absorption, achieving over 90% absorption in the range of $4.1-29.6 \mathrm{GHz}$ with a 151% relative bandwidth. Meanwhile, proposed structure exhibits insensitivity to wide-angle incidence, which can maintain 85% absorption under TM wave 75° oblique incidence. The efficiency and cost-effectiveness of this strategy make it highly promising for a wide range of applications.