New method of detection of weak anharmonic modes of a quartz crystal and its applications for generating multicrystal resonance frequencies

Abstract

An experimental method has been described for detection of various oscillating modes of a quartz crystal and accurate measurement of their resonance frequencies. In effect, a parallel tunable L-C circuit is coupled to the quartz crystal in a crystal oscillator circuit. As the L-C resonant frequency approaches one of the crystal mode resonance frequencies, the crystal takes control and makes the crystal oscillator circuit generate this frequency. The method, thus, not only enables accurate determination of crystal mode resonance frequencies but also permits generation of a number of stable frequencies using a single quartz crystal.