Electronic control method for a resonance frequency of a piezoelectric device using GIC circuit

Generally, it is difficult to realize the electrical control of a resonance frequency and the vibration mode of a piezoelectric device since the resonance frequency and the vibration mode are determined by both the dimensions and the material characteristics of the elements. On the contrary, the electrical inductance is connected with the electrode of the non-driving piezoelectric so as to vary the resonance frequency. In the control method, the solid coil, that is a passive element, was employed, and, hence, it is difficult to achieve the electronic control method of the piezoelectric device. In this report, the electronic control method of the resonance frequency of the piezoelectric element using GIC (generalized impedance converter) was proposed. The GIC circuit which consists of two operational amplifier and five passive electric elements realizes the inductance without the solid coil. The GIC was applied to controlling the resonance frequency of the piezoelectric device. To realize the electronic control method of GIC, the voltage controlled element was required. The current-voltage characteristics between a drain and a source ports of a MOS-FET was employed as a voltage controlled resistance. Finally, the voltage controlled method for the resonance frequency of the PZT device using GIC was achieved.