Barium Strontium Titanate Thick Films for Tunable Software-Defined Radio Front-Ends

In this paper, the samples preparation, experimental details, and characterization of the Electrophoretic Deposition (EPD) of a thick film Barium Strontium Titanate (BST) capacitor intended for radio-frequency applications are reported. With a bias voltage from 0 V to 20 V, the Ba
0.7
Sr
0.3
TiO
3
capacitor fabricated demonstrates 49% of tunability. The quality factor and the microwave (MW) loss tangent are calculated from 500 MHz to 5 GHz. Using an one-tone measurement setup, the small signal S-parameters measurements for the BST thick film capacitor are also presented by applying input signals from -20 dBm to 4 dBm. The linearity and loss tangent are analyzed considering a comparison of two different bias voltages, 0 V and 10 V. For the first time, the BST thick films fabricated with EPD are implemented and measured in the MW regime.