SU640419A1 - Piezoelectric resonator - Google Patents

Description

4 piezoelectric elements, the average diameter of the piezoelectric element is made equal,

iKsr.y

4pf

where n is an even number greater than two; Vcf is the average speed of propagation of elastic waves around the ring; h is the thickness of the bad element; kl is the frequency coefficient, and the excitation electrodes are applied in a quantity equal to 2, and the excitation electrodes having equal potentials are electrically connected.

The piezoelectric resonator operates as follows.

This ratio of the average diameter and wavelength of the excited thickness-shear oscillations, as well as the number and connection of the electrodes, makes it possible to excite the traveling wave mode in the ring resonator. This mode is characterized by a uniform distribution of the amplitude of mechanical stresses on the end surface of the resonator, and, therefore, the absence of a temperature gradient causing a frequency shift. The resonant frequency of the ring resonator is determined by the thickness and average diameter, therefore, its relative dimensions can be increased by an integer number of wavelengths.

Thus, the proposed piezoelectric resonator, which uses the traveling-wave mode of thickness-shear oscillations, is advantageously characterized by an improved temperature-frequency characteristic, increased quality, and less aging.

Claims (3)

1. USSR author's certificate number 320021, cl. N OZN 9/02, 1971. 2. Forward Germany No. 2000247, cl. N OZN 9/04, published. 1972. 3. Smagin A. G. Precision quartz resonators, M., 1964, p. 62.