Organic-Inorganic RF Composites with Enhanced Permittivity by Nanoparticle Additions

Organic-inorganic thermoplastic composites offer a cost-effective material choice with tuneable dielectric properties for various telecom components and applications. Typically such composites require substantial loading of inorganics to obtain a feasible level of permittivity at RF frequencies dramatically decreasing mechanical ruggedness and increasing losses. In this paper we demonstrate utilization of nanoparticle phase in BaSrTiO-polypropylene-graft-poly (styrene-stat-divenylbenzene) composite to enhance the high frequency properties and overcome the problems associated with high filler loading. The effect of nanosize silicon, silver and AlO additives with different volume fractions in complex permittivity was investigated up to 1 GHz. Significant increase in the effective permittivity of the composites with all the additives was observe, especially in the case of the nanosized silver particles where only 2 vol.% addition was able to enhance ε by 52% without increasing the dielectric losses when compared to the reference sample.