CoY hexaferrite-PEEK composites for integrated and miniaturized RF components

CoY hexaferrite-filled PEEK (poly ethyl ether ketone) composites were synthesized to characterize the effect of hexaferrites on their dielectric, magnetic and thermal properties for wireless sensing and communication applications. Fillers were synthesized from solid-state reaction route and blended with the thermoplastic polymer matrix. XRD was used to study the phase purity of the synthesised fillers. Impedance measurement showed permeability of ~2 with a loss tangent of 0.04 and frequency stability of permeability up to 800 MHz for higher filler loading. Dielectric property measurements using parallel-plate capacitance showed that the composites can attain a maximum dielectric constant up to 8 and a loss tangent of 0.005. Thermo mechanical Analyser was used to characterize the coefficient of linear thermal expansion (CTE) of the composites. The measured CTE closely matches that of organic substrates and copper, resulting in minimal CTE mismatch issues during processing and operation. VSM studies revealed soft magnetic characteristics of the composites. The results suggest the potential of this polymer composite substrate for integrated RF modules with miniaturized embedded passive components.