Magnetic nanocomposites for organic compatible miniaturized antennas and inductors

Current wireless systems are limited by RF technologies in their size, communication range, efficiency and cost. RF circuits are difficult to miniaturize without compromising performance. Antennas and inductors are major impediments for system miniaturization because of the lack of magnetic materials with suitable high frequency properties. Keeping antenna and inductor requirements into consideration, two magnetic nanocomposite systems - silica coated cobalt-BCB and Ni ferrite-epoxy were investigated as candidate materials. Nanocomposite thick film structures (125-225 microns) were screen printed onto organic substrates. Parallel plate capacitors and single coil coplanar inductors were fabricated on these films to characterize the electrical and magnetic properties of these materials at low and high frequencies. Electrical characterization showed that the Co/SiO₂ nanocomposite sample has a permeability and a matching permittivity of ∼10 at GHz frequency range making it a good antenna candidate. Both polymer matrix composites retain high permeability at 1-2 GHz.