JPS63102403A - Frequency adjusting method for oscillator - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a resonator used primarily as a resonant element in a high frequency circuit, such as an oscillator or a small filter.

2. Description of the Related Art In the field of wireless communication, IJ tube line type resonators are often used in oscillators and filters used in transmitters, receivers, etc. due to demands for smaller size and higher performance. For example, as shown in FIG. 3, as the basic structure of a strip line, a WXl line pattern (strip line) 2 is processed on a substrate 1 made of dielectric material (for example, a copper-clad laminate, a glass epoxy substrate, etc.). Ru.

FIG. 4 shows an example in which a 1/2 wavelength line is used as an oscillator in this strip line.

When used in an oscillator, transistor 3 and feedback capacitance 4.5
Furthermore, it is connected to a drive circuit including a bias system (omitted in the figure) through a coupling capacitor 6.

The required oscillation frequency of the oscillator is determined by the resonant frequency of the strip line 2, and the main factors determining the resonant frequency are the line length l (line width W) of the board 1, the board material, the board thickness, etc. .

Furthermore, on the drive circuit side, it is determined by the value of the transistor 3 or the capacitance between each terminal 4,5,6.

Problems to be Solved by the Invention However, during manufacturing and assembly, frequency deviations occur due to the etching accuracy of this resonator or variations in each component in the drive circuit section, resulting in a situation where the required oscillation frequency cannot be obtained. To avoid this kind of deviation, a common method is to install a voltage variable capacitance element (hereinafter referred to as a varactor) in a part of the circuit that can change the capacitance between the terminals depending on the voltage. Countermeasures can be taken by varying the capacitance and correcting the frequency, or by replacing parts of the drive circuit. However, regarding the method using a varactor, when configuring a low-class oscillator, the voltage applied to this varactor needs to be a DC voltage with low sopul noise, and when a ripple voltage is applied to this varactor, the frequency will vary depending on This leads to deterioration of stability. A redundant power supply filter circuit is required, and replacing parts of the drive circuit also increases the number of man-hours and is uneconomical.

The present invention solves the above-mentioned problems by reducing the number of man-hours and easily performing frequency correction.

Means for Solving the Problems In the present invention, a resonant capacitor and a ring-shaped microstrip line are provided, and the microstrip line is cut into a white shape from the center by a cutting means.

Function The present invention adjusts the resonance frequency by cutting a pattern. In order to facilitate the cutting operation, the strip line is set in a ring shape and the strip line is cut in a circle from the center of the ring shape. The resonant frequency can be varied by changing the line length and characteristic impedance.

Embodiment FIG. 1 shows a first embodiment of the present invention. 1st
As shown in the figure, a circular strip line 11 is formed by forming a normal straight strip line into a ring from a center point 12.
Next, a cutting means 12 such as a drill 7 is inserted from this central axis.
By cutting the IJ tube line into a circular shape (shaded area A), it is possible to change the line width of the IJ tube line, and hence the line length, thereby changing the resonant frequency of the resonator (strip line 11 and resonance capacitor 14).

FIG. 2 shows a second embodiment of the present invention, and shows a different method of cutting the strip line 11 from FIG. 1. As shown in Fig. 2, in order to reduce the influence of this cutting on the characteristics of the % type strip line, in particular, in the fake microstrip line 11a, the part where the high frequency current distribution is small, that is, the multiplier load Q of the resonator is less degraded. This is characterized in that the cutting center point B of the circle is located on the horizontal line of the center point 12a of the circle, away from the bonded and open ends.

In this way, deterioration of characteristics due to cutting can be minimized.

As described above, the present invention makes it possible to easily adjust the resonant frequency of a resonator, reducing the number of adjustment steps even when the resonator is incorporated into an oscillator or filter, and quickly adjusting the required frequency even when replacing parts. It is possible to adjust the results, and the economical effects, especially during mass production, are extremely significant.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing a method of adjusting the frequency of an oscillator in an embodiment of the present invention, FIG. 2 is a plan view of the oscillator showing a method of adjusting the frequency of an oscillator in a second embodiment of the invention, a) and (b) are plan views of a conventional IJ knob line and an oscillator using the same, and FIG. 4 is a circuit diagram of the oscillator. 10, 10a... strip line, 12.121...
Center point, 13... Cutting means, 14... Capacitor for resonance, A... Cutting portion, B... Center point of cutting circle. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 rA Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) A method for adjusting the frequency of an oscillator, characterized in that a resonant capacitor and an annular microstrip line are provided, and the microstrip line is cut into a circular shape from the center by a cutting means. (2) The method for adjusting the frequency of an oscillator according to claim 1, wherein the cutting means uses a drill. (3) A claim characterized in that, on the horizontal line of the center point of the annular microstrip line, the center of the circle to be cut by the cutting means is set at a position away from the coupled end and the open end of the microstrip line. The method for adjusting the frequency of an oscillator according to item 1.