Wireless energy transmission to piezoelectric component by flat spiral coil antenna-like structure

A compact electric field generator has been explored to transmit electric energy wirelessly to piezoelectric components by using the electric resonance of a flat spiral coil antenna-like structure and a capacitor in series. In the flat spiral coil antenna-like electric field generator, the ac electric field is transmitted wirelessly to the piezoelectric plate placed in a plane perpendicular to the plane of antenna. When the spiral coil antenna-like electric field generator and capacitor are in electric resonance, the wireless electric energy transmission to the piezoelectric component can be enhanced. At resonance frequency of 772 kHz and optimum electrical load resistance of 350 Ω, a maximum output power of 164.58 μW and energy conversion efficiency of 0.03% have been achieved wirelessly by the piezoelectric plate operating in the thickness vibration mode, placed 4 mm away from antenna plane with an input ac source power of 0.54 W, and an inductance of 0.0413 mH of the flat spiral coil antenna-like electric field generator.