A new electrostatic tunable capacitor for wide ranges of applications

A new electrostatically tunable capacitor for wide range of frequencies is proposed in this paper. A complete design rule is proposed to design a variable capacitor in the range of 0.01 pF-2.05 pF due t the its application. The designed capacitor occupies 0.03 mm2-1.12 mm2 space based on the required capacitance value which is so small comparing the related published works. The floating technique is used to get the high-quality factor. The quality factor of the proposed capacitor is in the range of 45 to 100 over the frequency range of 1.28 G to 2.78 GHz, and also the tunability range of the tunable capacitor is 374%. After presenting a complete design rule with the related equations, the proposed capacitor is used in an amplifier circuit with a spiral inductor and the performance of the proposed capacitor is evaluated and compared with other capacitors. The COMSOL Multiphysics is used for simulation.