Frequency dependence of electromagnetic radiation from a finite vibrating piezoelectric body

Abstract

We study electromagnetic radiation from a finite piezoelectric body in time-harmonic vibration through the analysis of piezoelectric crystal plate resonators. The polarization charge and free charge involved are obtained. To the lowest order, the charges are approximated by a vibrating electric dipole whose radiated power is then calculated. It is shown that the radiated power is formally proportional to the fourth power of the vibration frequency. As a consequence, the radiated power increases rapidly when the body becomes smaller, which is relevant in the miniaturization of resonant piezoelectric devices.