Ceramic disc capacitor composed of Al2O3-doped BSTO for application in voltage-controlled oscillator

Effect of the applied DC control voltage on the capacitance of the ferroelectric-based ceramic disc capacitor for application in voltage control oscillator has been studied. The ceramic disc capacitor is composed of Al2O3-doped barium strontium titanate. The capacitance of the ceramic disc capacitor decreases with increasing applied control voltage. Curve fitting works well for all capacitors composed of Al2O3-doped barium strontium titanate. Fitted grading coefficient varied with Al2O3 content has the same trend as exhibited by the grain size. This is due to the effect of internal stress among grains.