A Miniaturized 3-D Metamaterial Absorber With Wide Angle Stability

A miniaturized metamaterial absorber (MA) based on 3-D resonant structures is presented. The absorber exhibits near-unity absorption (>99%) at 2.08 GHz, thanks to the long electric length of the folded metal plate. The proposed structure has a unit cell size of 7 mm
$\times $
7 mm, which gives a ratio between periodicity and resonance wavelength of 1/20.6. Moreover, the proposed structure maintains absorption above 90% with incident angle reaching up to 60° and 70° for TE and TM polarizations, respectively. The stereo resonator and dielectric substrate included in this absorber are fabricated with the aid of the multimaterial hybrid microdroplet jetting modeling (MHMJM) technique. The measured absorption spectrum agrees closely with the simulations.