SU101593A1 - Piezoelectric resonator - Google Patents

Description

The 1m.enie of Iquartz piezoelectric resonators in electric filters is limited by the fact that they in many cases, unlike quartz resonators, have a length from the HOLueHKH to the length of the resonator that are sharply curved with additional resonances -: close to the main frequency . In such cases, the washer is not suitable for use in filters.

It is particularly difficult to use these resonators in cases where a resonator is required to have a large equivalent of inductance and, correspondingly, more volatile, which in itself makes it difficult to manufacture a resonator.

In order to increase the equivalent inductance of the resonator, the known technique of shortening the electrodes of the resonator can be applied.

However, in resonators with shortened electrodes of a part of the plate. not covered with electrodes, have other properties that differ from the properties of the parts of the plate coated with electrodes. As a result, shortening of the electrodes does not provide the possibility of obtaining the proper parameters of the resonator, in particular, the required temperature characteristics.

To achieve these capabilities, it is proposed to use piezoelectric resonators, in which the main surfaces of the crystal plate are fully metallized, and the reduction of the area of electrodes included in the electrosphere: PC circuit is carried out by separating the metallic coating and the non-metallic surface by E11C surface.

By measuring the area of the coatings that serve as electrodes and the coatings that are not included in the electrical circuit, it is possible to regulate to a certain extent the equivalent parameters and, consequently, the resonant and antiresonian frequency of the resonator.

FIG. 1-4, four versions of the proposed resonator are presented in two projections.

In the embodiment of FIG. 1, the metal coating on both sides of the crystal plate is divided into three parts 1, 2, 3 and I, 2 and 3 respectively, of which mid 2 and 2 are electrodes and serve to connect the resistor to the electrical circuit.

In the case of using a resonator as a quadrupole, each

from the middle parts 2 and 2, in turn, is divided into two isolated sections (Fig. ..2) .--. the voltage is supplied to both sections.

The separation of the metal coating into parts can be carried out as shown in FIG. 3 and 4.

Separation of metal coatings, paneled on both sides of the resonator plate, allows for a given plate thickness to obtain the necessary equivalent inductance and eliminate additional resonant frequencies, as well as to a certain extent, reduce the temperature coefficient of the resonator frequency.

FIG. one

PRIORITY AREA

A piezoelectric resonator, whose crystal plate, oscillating in the length direction, carries metal electrodes placed on both sides of the plate, occupying a part of the plate surface, about 20% in order to improve the electrical characteristics of the resonator, in particular reduce the temperature coefficient of frequency, metal coatings, electrically isolated from the electrodes and not included in the electrical circuit, are applied to the free surface areas of the plate;

FIG. 2

FIG. 3

FIG. four