Characterization of doped BST thin films deposited by sol-gel for tunable microwave devices

BST thin films with various dopants are growth by sol-gel method on Platonized silicon and MgO substrates. Thiers dielectric properties are investigated at low frequency(less than 1 MHz) on silicon with plate capacitor and high frequency (up to 15 GHz) by interdigital capacitor on MgO substrate. These results are discussed with the nature of dopant and show, Mg as very good candidate to reduce grain size and dielectric losses. In opposite K is good candidate as dopant of BST thin film to increase the drastically the tunability.