Analysis, Simulation and Measurements of CBS Antennas Loaded With Non-Uniformly Biased Ferrite Material

When ferrite materials are used in the design of the CBS antennas, they are usually magnetized by the applied magnetic field produced by an electromagnet or permanent magnets. In modeling of such antennas, it is common practice to ignore the actual distribution of the applied field and assume it is uniform. We demonstrate that such an assumption leads to inaccurate results when the applied field is severely non-uniform. In contrast to the previous formulations, a formulation presented here leads to accurate modeling and simulated results compare very well with measurement for both uniform and non-uniform field distributions. The utility of the proposed approach is especially evident for the case when the applied magnetic field is severely non-uniform.