Several Theoretical Perspectives of Ferrite-Based Materials—Part 1: Transmission Line Theory and Microwave Absorption

A theoretical model for microwave absorption from both forced non-resonance oscillation and resonance is constructed using the transmission line theory familiar to microwave engineers. The model covers both the single-phase ferrite and its composites of interest to material scientists, and can be applied to a variety of different absorption mechanisms. The transmission line theory is also shown to be consistent with the band theory of solids, a relationship that has not been revealed previously. The work bridges the gap between the interests of microwave engineers and material scientists.