Modeling a stripline ferrite phase shifter

A model is proposed for the behavior of transmission lines on ferrite substrates. This may be the first time a model has correctly described the absorption below the gyromagnetic resonant frequency corresponding to the magnetization at saturation, or /spl gamma/4/spl pi/M/sub s/. This new model should allow accurate prediction of impedances and propagation constants for frequencies operating close to this cutoff frequency, permitting more accurate transmission lines and transformers to be designed. Comparison with measured data from a low-temperature co-fired (LTCC) ferrite stripline phase shifter is given.