STUDY OF MAGNETIC MATERIALS AND ARTIFICIAL STRUCTURES FOR ELECTRMAGNETIC WAVE ABSORPTION

Abstract

Electromagnetic wave absorption was growing demanded in both military and commercial applications. To obtain high performance absorptive devices, this thesis presents new solutions using both magnetic materials and artificial structures and discusses their co-design guidelines. First, we address ultra-thin absorbers with thickness <0.03λL and bandwidth >1.86:1 using frequency-selective magnetic materials and capacitive 2D FSS layer. Then, we designed broadband and thin absorbers with thickness <0.035λL and bandwidth >3.5:1 and derived their theoretical limitations. Third, ultra-wideband 2D rasorber with bandwidth > 130:1 is presented by co-designing 2D FSS layers and ferrite ceramic. Finally, we expand absorption bands of 3D rasorber by incorporating multi-layer structures and magnetic materials. With a sextuple operation bandwidth, a wide absorption band could be designed at either the lower or the higher absorption band.