Magnetodielectric Thin Film Heterostructure With High Permeability and Permittivity

This paper discusses combined high-permeability and high-permittivity magnetodielectric thin films for microwaves. The results are based on outstanding material properties: epsiv = 18, mu_dc = 180, f_r = 4.8 GHz, and Deltaf= 480 MHz. This material combines exchange coupled high-magnetization ferromagnetic thin films and SrTiO₃ materials as dielectric lamination. The benefit of such magnetodielectric material is expected for size reduction of 1/2 wave resonators. To this end, this material has been integrated with different coplanar waveguides (CPW) structures. Here, we discuss the effect of increasing the overlap from the central part of ribbon to the lateral grounds. The potential of miniaturization based on the enhancement of the constant of propagation is evaluated for different configurations up to 40%. We also show that the conductivity of the ferromagnetic layers may play a key role in the propagation when the material overlaps the gap of the CPW lowering the expected benefit of the permittivity.