Metaferrites: using electromagnetic bandgap structures to synthesize metamaterial ferrites

A methodology is presented for the design synthesis of metamaterial ferrites, or metaferrites, that retain their desirable magnetic properties at frequencies above 1 GHz. The design synthesis is accomplished by optimizing a high impedance frequency selective surface (HZ-FSS) structure via a genetic algorithm (GA) for the desired effective permeability of an equivalent magnetic substrate backed by a perfect electric conductor ground plane. The ability to optimize the design parameters of these HZ-FSS structures allows for the possibility of synthesizing low-loss dispersive metaferrites with either a positive or a negative real part of the effective permeability at the desired operating frequency band. The results presented in this paper demonstrate five possible metaferrite designs: two with the associated real and imaginary permeabilities for use as low-loss magnetic materials, and three designs for use as absorbing materials.