JPS63127606A - Resonance frequency adjusting method for dielectric resonator - Google Patents

Abstract

PURPOSE:To simplify the frequency adjustment by cutting the electrode at the outer circumferential face of the resonator while varying the depth at a prescribed width. CONSTITUTION:Electrodes 12, 13 of the resonator 10 are formed respectively to the inner and outer circumference of the cylindrical dielectric ceramic 11. The upper flat face in an open end from which a ceramic is exposed. The electrode 13 at the outer circumference is cut by a prescribed width from the open to expose the ceramic. In this case, the cut width is selected to be nearly 1/8 of the entire circumference and the axial length is selected to be a size by obtaining a desired frequency. Thus, the quantitative adjustment is applied and the length is calculated from the deviation of frequency in advance and the cutting by the quantity is attained. Thus, the adjustment is conducted efficiently in a short time.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for adjusting the resonant frequency of a dielectric resonator used as a resonator or a filter, and particularly relates to a method for adjusting the resonant frequency of a dielectric resonator used as a resonator or a filter. This invention relates to a frequency adjustment method.

[Prior art]

Dielectric coaxial resonators using ceramic dielectrics are used in many fields as resonators or filters in high frequency bands. It consists of a cylindrical ceramic dielectric,
Electrodes are formed on the inner circumferential surface and the outer circumferential surface, respectively.

The dimensions are determined depending on the frequency used, but in practice the resonant frequency needs to be adjusted.

Several methods have been proposed for adjusting the resonance frequency.
For example, JP-A-58-204602 and JP-A-60-
This is shown in, for example, Japanese Patent No. 52102. In all of these, the open end of the cylindrical resonator or the electrode or ceramic dielectric of the short-circuit electrode is omitted.

In the above adjustment method, it is necessary to strictly control the area to be removed, etc., and sufficient precision is required for processing. Furthermore, processing becomes difficult when adjustments are required after being assembled into a filter or the like.

〔the purpose〕

It is an object of the present invention to solve the above-mentioned problems and provide a method for adjusting the resonance frequency of a dielectric resonator that is easy to process and easy to control.

Another object of the present invention is to provide a method that allows adjustment even after being incorporated as a filter or the like.

[Means for solving problems]

The present invention achieves the above object by removing the electrodes on the outer peripheral surface from the open end while changing the depth over a constant width.

That is, in a method for adjusting the resonant frequency of a dielectric resonator in which electrodes are formed on the inner and outer circumferential surfaces of a cylindrical ceramic dielectric, the electrodes on the outer circumferential surface are moved in the axial direction by a constant width from the open end. The feature is that the resonant frequency of the dielectric resonator is adjusted by removing the length.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention.

In the dielectric resonator 10, electrodes 12 and 13 are formed on the inner and outer peripheral surfaces of a cylindrical dielectric ceramic 11, respectively. The upper flat surface is an open end with exposed ceramic. The electrode 13 on the outer peripheral surface is shaved to a certain width from the open end side to expose the ceramic.

In this case, the width is set to one-eighth of the total circumference, and the length in the axial direction is set to a size that allows the desired frequency to be obtained.

That is, by utilizing the fact that the frequency gradually changes depending on the length Δl, it is cut to a dimension corresponding to the amount of change in the frequency.

FIG. 3 shows how the resonance frequency changes when the length to be cut is changed in this way. The horizontal axis shows the length, ie, a, and the vertical axis shows the amount of frequency change and the amount of Q change. As the depth increases with a width of 1/8, the resonant frequency increases, and at 3a+m it is approximately 6 Mn2.5mm.
The resonant frequency increased by about 10 MH2. length 6m
It was confirmed that when the value is made larger than +1, the resonant frequency decreases.

It was also confirmed that when the electrodes on the outer peripheral surface were removed in this way, the Q value decreased. If the decrease in Q becomes too large, it will greatly affect the characteristics of the resonator, so it is necessary to keep the amount of decrease within a range that does not become too large. Although not shown in the figure, when the length exceeds 8 mm, the Q value decreases significantly, making it unsuitable for practical use.

Considering the above measurement results, it is preferable to keep the length to about 5 to 6 knots.

FIG. 2 is a perspective view showing another embodiment of the invention. The electrode 23 on the outer circumferential surface is shaved off in the same manner as described above, but a part of the electrode is left and floated without being removed. In this case, processing is simpler because it is only necessary to cut the electrode along a line of a certain width. The measurement results were also almost the same as in the previous case. Additionally, since the dielectric exposed surface only needs to be smaller, it is less susceptible to external influences.

The removal of the electrode on the outer peripheral surface can be done with a beam from a laser processing machine, etc., or it can be polished with a router, sandblasting, etc. as has been done conventionally, and it is possible to remove not only the electrode but also the dielectric ceramic. Even if it is polished, there is almost no effect on the characteristics.

Although the above description has been made regarding a cylindrical dielectric resonator, it can also be applied to a prismatic dielectric resonator, a block-shaped dielectric resonator in which two or more elements are integrated, and a dielectric filter.

〔effect〕

According to the present invention, it is possible to change the method of adjusting the resonant frequency, which not only facilitates processing but also facilitates adjustment control.

The method of the present invention allows for more quantitative adjustment than conventional methods, and it is possible to calculate the length in advance from the frequency deviation and delete it using that value, without having to gradually grind the set resonance frequency. can. Therefore, it is efficient in a short time (
Can be adjusted.

Another great advantage is that it can be adjusted even after it has been incorporated into a filter or the like.

[Brief explanation of the drawing]

FIGS. 1 and 2 are perspective views showing embodiments of the present invention, and FIG. 3 is an explanatory diagram showing the relationship between the size of deletion and changes in frequency and the like. 10: Dielectric resonator 11: Dielectric ceramic 13.2
3: Outer surface electrode

Claims (1)

[Claims] In a method for adjusting the resonance frequency of a dielectric resonator in which electrodes are formed on the inner and outer circumferential surfaces of a cylindrical ceramic dielectric, the electrodes on the outer circumferential surface are arranged at a predetermined length in the axial direction with a constant width from the open end. 1. A method for adjusting the resonant frequency of a dielectric resonator, the method comprising: adjusting the resonant frequency of the dielectric resonator by removing the resonant frequency of the dielectric resonator.