Efficient full-wave characterization of microstrip lines fabricated on magnetized ferrites with arbitrarily oriented bias field

The spectral domain approach (SDA) is used for the full-wave determination of the propagation constant and characteristic impedance of microstrip line s fabricated on ferrite substrates with arbitrarily oriented bias magnetic field. Numerical problems arising from the numerical computation of the mic rostrip lines parameters for high values of the spectral variables are avoi ded by using asymptotically equivalent structures. The evaluation of the in finite integrals involved in the determination of the propagation constant is efficiently carried out by means of a technique based on the interpolati on of the spectral dyadic Green's function. The numerical results obtained indicate that for every microstrip line fabricated on ferrite substrate the re is a frequency region in which propagation is not feasible, the limits o f this frequency region being strongly dependent on both the orientation an d the magnitude of the bias magnetic held. Also, the authors show that for every frequency, both the propagation constant and the impedance of the mic rostrip lines can be adjusted over a wide range by varying the bias magneti c field magnitude.