Piezoelectric ceramic resonant transducer with stable frequency

摘要

The invention reduces variability of the resonant frequency in piezoelectric ceramic transducers having a vibratory assembly comprising a flexible diaphragm carrying a ceramic disk sensor. The clamped edge of the diaphragm is typically offset from the plane of the vibratory assembly and is coupled to that assembly by generally cylindrical structure having flexibility in a radial direction. That flexibility partially isolates the vibratory assembly from effects such as structural variability of the clamping means and differential thermal expansion at the clamp. The degree of that isolation is preferably selected by suitable design of the coupling structure to provide approximate compensation for thermal effects due to other parameters of the system.