P. Gelin et K. Berthoupichavant, NEW CONSISTENT MODEL FOR FERRITE PERMEABILITY TENSOR WITH ARBITRARY MAGNETIZATION STATE, IEEE transactions on microwave theory and techniques, 45(8), 1997, pp. 1185-1192
Partially magnetized ferrites play an important role in a large class
of microwave devices. For instance, when the optimal design of circula
tors, which operate with ferrite in the low magnetic field region, and
other ferrite devices (phase shifters, isolators etc.) are considered
, permeability tensor is required for arbitrary magnetization. The exi
sting models do not simultaneously provide all tensor components, and
their validity domain is limited, The proposed model provides integral
expressions for all permeability tensor components, which can be trea
ted numerically without difficulties, The physical nature of the model
enforces the causal aspect that is required when numerical time-domai
n methods (such as finite-difference time domain (FDTD), transmission-
line matrix (TLM), time-domain finite-element method (TDFEM), etc.) ar
e used, Finally, the comparison with measurements or specific cases, w
hich can be treated by available models, demonstrates the validity of
the proposed approach.