Manipulating Absorption Properties of Gyromagnetic Ferrite with Bias Magnetic Field

Based on gyromagnetic ferrite, we demonstrate tunable microwave absorbers by controlling bias magnetic field (BMF). Unlike previous works, we explore not only the magnetic field intensity, the bias directions are also taken comprehensive study. We derivate the theoretical analytical solutions for the reflective of metal-backed bulk ferrite under two kinds of basic bias magnetic field directions. The consistence between full wave simulations and analytical formulas proves the correctness of our theoretical analysis. The reflective peaks can be adjust by changing the bias magnetic field and the gyromagnetic ferrite possess distinguished performance when different bias modes are applied. All the results show that gyromagnetic ferrite has great potential for manipulating the reflectivity of electromagnetic (EM) wave.