Electromagnetic radiation from an AT-cut quartz plate under lateral-field excitation

Equations of linear piezoelectricity (with the quasistatic approximation) for the plate and Maxwell´s equations for the electromagnetic field in the surrounding vacuum are solved for the thickness-shear vibrations of an AT-cut quartz plate. For an AT-cut plate vibrating near the thickness-shear resonance excited by a uniform, lateral electric field of magnitude 1 V/m, the electromagnetic energy radiated from each face is about 0.13 μW/cm². The radiated power is about 0.1 μW/cm² if the plate is excited by a shearing face-traction which produces a strain of 10^-5. The present solution is compared in detail with R.D. Mindlin´s solution (1972) of equations of piezoelectromagnetism (without the quasistatic approximation) for the thickness-shear vibrations excited by shearing face traction