JPH03155209A - Adjustment method for crystal oscillator - Google Patents

Abstract

PURPOSE:To adjust the frequency and the frequency temperature characteristic by varying the mass of a crystal resonator and its vibration mode with vapor- deposition or laser or the like to the GT cut crystal resonator. CONSTITUTION:The oscillator consists of a GT cut crystal resonator 10 and its oscillation circuit, and while the GT cut crystal resonator 10 connects to a signal generator, the mass of the GT cut crystal resonator 10 is increased or decreased by vapor-deposition or laser or the like to change the vibration mode. Thus, the oscillating frequency and the frequency temperature characteristic are easily adjusted. Then the energy loss due to a circuit network using a complicated temperature sensing element is avoided and the power consumption is reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a reference signal generator that specifies channel spacing in wireless communication, which is widely applied in automobile telephones, etc., and in particular uses a crystal oscillator as a reference element. Small size, used as
This invention relates to a method of adjusting a high-precision oscillator (hereinafter referred to as a crystal oscillator).

[Summary of the invention]

The present invention provides a method for adjusting a crystal oscillator, characterized in that in a crystal oscillator using a GT-cut crystal resonator, frequency adjustment and temperature characteristic adjustment are performed in the state of the crystal oscillator, and adjustment means is applied to the GT-cut crystal resonator. It is related to.

[Conventional technology]

A conventional temperature compensated crystal oscillator is shown in FIG.

For details of the main element electrical variable capacitance element l, please refer to Japanese Patent Laid-Open No. 57-
It is disclosed in Japanese Patent No. 5369. Further, the application of variable capacitance elements to crystal oscillators is disclosed in detail in JR'E magazine, January 1986 issue, pages 32-36.

The ambient temperature is detected by a thermistor 12, and the bias voltage of the electrical variable capacitance element is changed by a resistor array including the thermistor, thereby compensating the frequency-temperature characteristics of the crystal resonator. The degree of this compensation was set by finely selecting the resistors 3 and 4 shown in FIG. 2 and adjusting them by the combined resistance.

[Problem to be solved by the invention]

The circuit diagram of a temperature compensated crystal oscillator according to the prior art is shown in Figure 2 (
The implementation diagram of the temperature-compensated crystal oscillator is shown in FIG. The shape is shown in Figure 2(b).

(As shown in C1, it becomes larger. Also, since the number of elements is large, it is difficult to manage the reliability of each element, and long-term reliability deteriorates.

Furthermore, 211ffl(di is the frequency-temperature characteristic of a single crystal resonator, FIG. The frequency-temperature characteristics after compensation are shown. Even if the frequency-temperature characteristics are guaranteed with a single crystal resonator, it will change depending on the temperature characteristics of the load capacitance on the circuit side. Therefore, good temperature characteristics Even if a crystal oscillator is made using a crystal resonator with It took.

The present invention has been developed in view of the above-mentioned circumstances, and has a simple circuit configuration, and provides high precision that allows frequency adjustment and frequency temperature characteristic adjustment to be made to a GT cut crystal resonator when it is used as a crystal oscillator. The purpose is to provide a crystal oscillator.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention has a simple configuration of an oscillation circuit consisting of a GT-cut crystal resonator and its oscillation circuit, and a crystal oscillator. The mass of the crystal oscillator, etc.
This problem is solved by making it possible to adjust the frequency and frequency temperature characteristics by changing the vibration form.

〔Example〕

Next, an embodiment of the present invention will be described with reference to FIG. 1st
FIG. 1b+ is an example of a circuit diagram showing the configuration of the present invention. The circuit diagram 0 is a Colpitts type crystal oscillation circuit. 1st
FIG. 1b+ shows the frequency-temperature characteristics of a crystal oscillator obtained by mounting it on an oscillation circuit before adjusting the frequency of the crystal resonator and adjusting the frequency-temperature characteristics.

FIG. 1 [el] is the frequency-temperature characteristic of the crystal oscillator after changing the mass and vibration form of the crystal oscillator by thinly coating the crystal oscillator or using a laser or the like.

Since the frequency and frequency temperature characteristics are adjusted after the oscillation circuit is made, the number of steps can be reduced compared to the conventional method, and there is no need to adjust the circuit network using complicated temperature sensing elements.

1b+, (C1 shows an embodiment of the structure of the crystal oscillator of the present invention. FIG. 1b+ shows a plan view, and FIG. 1b+
shows a cross-sectional view. We were able to create a smaller crystal oscillator compared to conventional temperature compensated crystal oscillators.

Figures 3 (al, tbl and 4) show other embodiments of the present invention, Figure 3 (fat) is a plan view of the case housed in a cylindrical case, Figure 4 (tbl) is its cross-sectional view, and Figure 4 (vertical) It is a top view accommodated in a mold case.

FIG. 5 shows a circuit configuration of another embodiment of the present invention.

An electrical variable capacitance element 8 is included in a Colpitts crystal oscillator. As a result, the frequency-temperature characteristic can be adjusted by the crystal resonator IO, and the frequency can be adjusted by the electrical variable capacitance element 8. Frequency adjustment is done by increasing or decreasing mass, which generates heat, which causes a change in frequency after frequency adjustment. allows for fine adjustment.

〔Effect of the invention〕

As described above, according to the present invention, in a signal generator composed of a CT-cut crystal resonator and its oscillation circuit, when the signal generator is connected to the GT-cut crystal resonator or The oscillation frequency and the frequency-temperature characteristics can be adjusted very easily by increasing or decreasing the mass using the laser beam IJ''-, etc., and changing the form of vibration.

The present invention not only reduces the number of components and improves reliability, but also eliminates energy loss due to a circuit network using a complicated temperature-sensitive element, resulting in a compact high-precision crystal oscillator with low power consumption. Furthermore, by using an electrical variable capacitance element in the crystal oscillation circuit of the present invention, a crystal oscillator with improved frequency adjustment can be obtained, and the present invention has many effects on realizing a high-precision crystal oscillator. It has the following.

[Brief explanation of the drawing]

Figure 1 (al is a circuit diagram showing the configuration of the oscillation circuit of the present invention, Figure 1 (bl), (C1 is a plan view (bl and cross-sectional view tc+, Figure 1 (di,
tel indicates the characteristics of the present invention, and is a characteristic diagram of before adjustment (di) and adjustment 77 (el). fbl, (C) is a cross-sectional view (C1, Fig. 2 (d),
tel and ffl indicate the characteristics of a conventional temperature-compensated crystal oscillator, and are the characteristics of the resonator alone (di, the characteristic combined with the circuit tel, and the adjusted characteristic (fl). Figure 3 (a)
g, fbl are a plan view (al) and a cross-sectional view fbl of another embodiment of the present invention, FIG. 4 is a plan view of another embodiment of the present invention, and FIG. 5 is a circuit configuration of another embodiment of the present invention. 1... Electrical variable capacitance element 2, 3.4.5.6.7.21... Resistor 8.9... Capacitor 10.10°... Crystal resonator 11・・・
・Output terminal 12...Thermistor 13...Inverter 15...IC16...A line
17.19...Adhesive 18...Ceramic container 19...Metal container 20...Lead terminal or more

Claims (2)

[Claims] (1) In a method for adjusting a signal generator composed of a GT-cut crystal resonator and its oscillation circuit, increasing or decreasing the mass of the GT-cut crystal resonator by vapor deposition, laser, etc. in the state of the signal generator. A method for adjusting a crystal oscillator, characterized in that frequency adjustment and frequency temperature characteristics are adjusted by changing the form of vibration. (2) In claim 1, the GT cut crystal resonator only adjusts the frequency temperature characteristic by changing the mass and vibration form by vapor deposition or laser, and the frequency adjustment is performed using an electrical variable capacitance element. , a crystal oscillator adjustment method characterized by being performed externally.