Complex permeability extraction of FeCo nanoparticles using annular ring resonator and its RF applications

Reconfigurable and tunable antennas/filters are of interest in various radio frequency (RF) applications. This paper addresses use of FeCo soft magnetic nanoparticles for magnetically tuned and reconfigured resonators, filters, and antennas. The RF component designs considered are based on annular ring resonator structures with a composite substrate of 30 nm cubic magnetic Fe60Co40 nanoparticles deposited on an FR4 substrate. Accurate permeability extraction of Fe60Co40 is performed for a ring resonator at 3.0 GHz with and without external magnetic field biases. Complex permeability extraction procedure is based on best fitting of simulated scattering parameters using finite element method (FEM) electromagnetic field simulator to the measurement results of the composite substrate. The extracted results of soft magnetic permeability are used along with an external magnetic field to develop tunable filter and antenna components for wireless applications.