The synthesis of metamaterial ferrites for RF applications using electromagnetic bandgap structures

It has been well known for many years that the desirable properties of conventional ferrite materials are seriously degraded for frequencies above 1 GHz. The paper demonstrates that electromagnetic bandgap (EBG) structures may be interpreted as an equivalent PEC-backed slab of magnetic material with a frequency dependent permeability. A design methodology is presented for realizing a metaferrite material using a GA optimization procedure. A standard HZ-FSS (high-impedance frequency selective surface) structure is shown to be equivalent to a thin PEC-backed slab of magnetic material with a frequency dependent permeability. By optimizing the surface impedance of the HZ-FSS, it is possible to synthesize a metaferrite with nearly any desired real and imaginary values of permeability. Finally, this design procedure allows for a low-loss negative permeability metaferrite to be realized, with potential application to the design of left-handed or double negative media.