JPS63127604A - Resonance frequency adjusting method for dielectric resonator - Google Patents

Abstract

PURPOSE:To facilitate the processing and the control of adjustment by forming a slot from the inner to the outer circumference of an open end face of a resona tor and cutting it while varying the depth. CONSTITUTION:Electrodes 12, 13 are formed to the inner and outer circumfer ence of a cylindrical dielectric ceramic 11 in a dielectric resonator 10 and the upper flat face is an open end where the ceramic is exposed. The slot 14 is formed to the uniform depth from the inner to the outer circumference in the ceramic 11 of the open end face. In this case, the width of the slot is selected to be 0.5mm and the depth from the open end face is selected to be a size to obtain a desired frequency. The gradual change in the frequency by the depth l of the slot 14 is utilized to make a depth up to the dimension in response to the variable quantity of the frequency. Thus, the processing is facilitated and also the control of adjustment is facilitated.

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, there is no suitable method for increasing the resonance frequency by processing the open end.

〔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 in which the resonant frequency can be increased only by processing the open end face.

[Means for solving problems]

The present invention achieves the above object by forming a groove extending from the inner circumference to the outer circumference on the open end surface and removing the groove while changing its depth.

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 ceramic dielectric with an open end surface has a uniform depth from the inner circumferential surface to the outer circumferential surface. The feature is that a groove is formed and the resonant frequency is adjusted depending on the depth of the groove.

〔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. A groove 14 is formed in the open end surface of the dielectric ceramic 11 from the inner peripheral surface to the outer peripheral surface, and this groove is formed to have a uniform depth. In this case, the width of the groove is 0.5+a
m, and the depth from the open end surface is a dimension that allows the desired frequency to be obtained. That is, by utilizing the fact that the frequency gradually changes depending on the depth dimension Δt, the depth is increased to a dimension corresponding to the amount of change in the frequency.

FIG. 3 shows how the resonant frequency changes when the depth of the groove is changed in this way. The horizontal axis represents the depth, ie, a, and the vertical axis represents the amount of frequency change and the amount of Q change. The unit of At is ll11. 0.
As the depth increases with a width of 51 am, the resonant frequency increases, approximately 2 MHz for lvw and approximately 6 MHz for 2 mm.
The resonant frequency has increased. If the depth is greater than 2 mm, the electrodes on the inner circumferential surface will also be shaved off, which will impede use as a resonator.

It was also confirmed that forming grooves in the open end surface in this manner lowers the Q. 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. However, in the present invention, the decrease in Q was slight within the above range of 211II+.

Considering the above measurement results, it is preferable to keep the depth of the groove within 2 mm.

FIG. 2 is a perspective view showing another embodiment of the invention. Two grooves 24a and 24b are formed on the open end surface.
The book grooves are formed with the same width and depth. The same FIG. 2 shows the change in characteristics when the width is set to 0.5 m as in the previous example and the depth is varied in the range from 0 to 21*lll. The increase in frequency is larger than in the case of one wire, about 5 MHz at 11 and about 12 MHz at 2 ma+.
The amount of change increases with z. However, the amount of decrease in Q becomes slightly larger.

The grooves on the open end surface can be removed using a router or the like, as has been done in the past. Since grooves with the same width and depth are formed from the inner circumferential surface to the outer circumferential surface, cutting can be performed extremely easily and dimensions can be easily controlled.

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 allows easy control of adjustment).

Another great advantage is that it is possible to increase the resonance frequency by processing the open end face.

[Brief Description of the Drawings] Figures 1 and 2 are perspective views showing embodiments of the present invention, and Figure 3 shows changes in groove depth and frequency when there are one and two grooves, respectively. It is an explanatory diagram showing a relationship. lO: Dielectric resonator ll: Dielectric ceramic 14.2
4: Groove

Claims (1)

[Claims] 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, grooves of uniform depth are formed in the open-end ceramic dielectric from the inner circumferential surface to the outer circumferential surface. 1. A method for adjusting the resonant frequency of a dielectric resonator, the method comprising: forming a groove, and adjusting the resonant frequency depending on the depth of the groove.