An improved fabrication method of high-k and low-loss polymer composites with sintered ceramic fillers for microwave applications

An improved method for fabrication of polymer ceramic nanocomposites is presented for producing high-permittivity and low-loss flexible substrates. The PDMS-ceramic filler composite substrates with particle loading concentration ranging from 10% to 30% were prepared and characterized up to 17 GHz using cavity resonator testers. For the low frequency band of 0.4 to 4.4 GHz, 25% loaded PDMS-NdTiO3 composites with sintered fillers have shown promising electromagnetic properties with permittivity (ε_r~8.66) and loss tangent (tanδ_d <; 0.0128). The same material has exhibited very stable dielectric permittivity (ε_r~9.22) and loss tangent (tanδ_d <; 0.0249) at higher frequencies up to 17GHz.