<p>In this work, a simplified permeability tensor is proposed for partially magnetized ferrite operating above their gyromagnetic resonance frequency. The proposed tensor components were examined in the frequency domain and the obtained results are in good agreement with those obtained using the conventional components. Transforming the constitutive relation based on the proposed permeability tensor allowed obtaining simple time-domain equations for the characterization of partially-magnetized ferrites. We implemented those equations, together with curl Maxwell equations, using finite-difference time-domain method for the dispersion analysis of some structures loaded with partially-magnetized ferrite: good agreement was obtained when compared to exact results.</p>