Variable capacitance device

A variable capacitance device, comprising:

• a semiconductor substrate;
• a redistribution layer disposed on a surface of the semiconductor substrate;
• a plurality of terminal electrodes including a first input/output terminal, a second input/output terminal, a control voltage terminal and a ground terminal;
• a variable capacitance element formed in the redistribution layer from a pair of capacitor electrodes electrically connected to the first input/output terminal and the second input/output terminal, respectively, and a ferroelectric thin film disposed between the pair of capacitor electrodes;
• an ESD protection element formed in the semiconductor substrate and being electrically connected between either the first input/output terminal or the second input/output terminal and the ground terminal;
• one or more resistance elements, the control voltage input terminal being electrically connected to the variable capacitance element through one or more of the resistance elements such that the capacitance of the variable capacitance element varies as a function of a control voltage applied to the control voltage input terminal;
• and
• the physical arrangement of the one or more of the resistance elements, the ESD protection element, the variable capacitive element and the plurality of terminal electrodes being such that the one or more resistance elements are physically located between the ESD protection element and the plurality of terminal electrodes and that the one or more resistance elements are physically located between the variable capacitance element and the plurality of terminal electrodes.