SU961101A1 - Piezoelectric resonator of shift oscillations - Google Patents

Description

The invention relates to electronics and can be used in piezoelectric devices.

A known piezoelectric resonator containing a piezoelectric element with holes at its edges and rivets passing ⁵ through them, connected to the L-shaped mounting racks and down conductors, the main surface of the piezoelectric element located parallel to the racks of the crystal holder [1].

A disadvantage of this piezoelectric 'resonator is low operational reliability due to the direct ₁₅ Time constant electric conduction contact electrode rivet, particularly by mechanical action.

Closest to the proposed one is a piezoelectric shear cavity resonator containing a piezoelectric element with holes along the periphery and a crystal holder with supports 2 passing through these holes [2].

A disadvantage of the known piezoelectric resonator is the low quality factor due to the loss of the vibrational energy of the piezoelectric element in the fastening elements ^ due to the insufficient rigidity of the mounting racks to the deformation of the piezoelectric element.

The aim of the invention is to improve the quality factor of a piezoelectric shear resonator.

The goal is achieved in that in a piezoelectric shear resonator containing a piezoelectric element with holes along the periphery and a crystal holder with uprights passing through these holes, the holes in the piezoelectric element and the cross section of the upper ends of the crystal holder racks are made in the form of a polygon or oval, the major axis of symmetry of which parallel to the vector of vibrational displacements.

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In FIG. 1 shows a piezoelectric shear resonator;

in FIG. 2 - element with holes.

The piezoelectric shear resonator contains a piezoelectric element 1 with holes 2 along the periphery and a crystal holder with uprights 3 (Fig. 1). The holes in the piezoelectric element and the cross section of the upper ends of the crystal holder racks are made in the form of a polygon (for example, a rectangle) or an oval (Fig. 2), the large axis of symmetry of which is parallel to the vibrational displacement vector V.

The racks 3 of the crystal holder are made of an elastic material, such as Kovar, and serve simultaneously as down conductors. The piezoelectric element 1 is mounted with its holes 2 on the protrusions and rests on the platforms of the racks 3 of the crystal holder, which ensures a stable position of the piezoelectric element 1 on these racks 3 "

Fluctuations in the piezoelectric element 1 cause bending deformation of the mounting racks 3 and the propagation of elastic vibrations in the mounting system. But since the holes 2 in the piezoelectric element 1 and the cross section of the upper ends of the racks 3 of the crystal holder are made of a certain shape and are located accordingly with respect to the vector of vibrational displacements, the elastic wave is reflected from the boundary of the piezoelectric element - holder and returns back to the piezoelectric element.

1101 4

Thus, an increase in the bending stiffness of the crystal holder racks to deformations caused by shear vibrations of the piezoelectric element, due to a 5 increase in the moment of inertia, reduces the acoustic energy transfer to the fastening system and increases the quality factor of the resonator.

The proposed piezoelectric Yu resonator of shear oscillations makes it possible to increase the quality factor of the resonator by 56 times in comparison with the known one. The proposed design of the resonator allows to mechanize the laborious 15 installation process.

Claims (2)

This invention relates to electronics and can be used in piezoelectric devices. A piezoelectric resonator is known, which contains a piezoelectric element with openings along its edges and rivets passing through them connected to an L-shaped mounting struts, and the main surfaces of the piezoelectric element are parallel to the supports of the crystal holder 1. The disadvantage of this piezoelectric resonator is low operational reliability from - due to time-non-constant electrical contact of the electrode-rivet, especially during mechanical actions. The closest to the proposed A piezoelectric resonator of shear oscillations, containing a piezoelectric element with openings in the periphery and a crystal holder with a rack passing through these openings CZ. The disadvantage of the known piezoelectric resonator is the low Q-factor due to the loss of the vibrational energy of the piezoelectric element in the fastening elements due to insufficient rigidity of the mounting racks to de (1 piezoelectric element. The aim of the invention is to increase the Q-factor of the piezoelectric shear vibration resonator. The aim is in a piezoelectric resonator of shear oscillations containing a piezoelectric element with apertures along the periphery and a crystal holder with racks passing through these apertures The holes in the piezoelectric element and the cross-section of the upper ends of the crystal holder racks are made in (} the polygon or oval yurma, the major axis of symmetry of which is parallel to the vector of oscillatory displacements. 39 Figure 1 shows the piezoelectric resonator of shear oscillations in Figure 2 - an element with holes. The piezoelectric resonator of shear vibrations contains a piezoelectric element 1 with holes 2 in the periphery and a crystal holder with columns 3 (Fig. 1). The holes in the piezoelectric element and the cross section of the upper ends of the crystal holder racks are made in the shape of a polygon (for example, a rectangle) or an oval (Fig. 2), whose major axis of symmetry is parallel to the vector of oscillatory displacements V. The struts 3 of the crystal holder are made of elastic material, for example, a covarium and serve as current leads. The piezoelectric element 1 is mounted with its holes 2 on the protrusions and rests on the platforms of the crystal holder racks 3, which ensures a stable position of the piezoelectric element 1 on these racks 3 The oscillations in the piezoelectric element 1 cause the bending deformation of the assembly racks 3 and the propagation of elastic oscillations into the mounting system. But since the holes 2 in the piezoelectric element and the cross section of the upper ends of the struts 3 of the crystal carrier are of a certain shape and arranged in a corresponding manner with respect to the vector of oscillatory displacements, the elastic wave is reflected from the border of the piezo holder element and returns back to the piezo element. 14 Thus, an increase in the flexural rigidity of the crystal holder racks to deformations caused by the shear vibrations of the piezoelectric element, by increasing the moment of inertia, reduces the acoustic energy transfer to the mounting system and increases the Q factor of the resonator. The proposed piezoelectric resonator of shear oscillations makes it possible to increase the Q factor of the resonator in comparison with the known. The proposed resonator design allows mechanization of a laborious installation process. The invention of a piezoelectric resonator of shear oscillations, containing a piezoelectric element with apertures on the periphery and a crystal holder with racks passing through these apertures, in order to improve the quality factor, the holes in the piezoelectric element and the cross section of the upper ends of the crystal holder racks are polygonal. or an oval whose large axis of symmetry is parallel to the vector of oscillation, body displacements. Sources of information taken into account in the examination 1. US patent number 325770, class 29-25.35, 1967. 2. Japanese Patent K 2 577/68, cl. 100 B1, 1968 (prototype).