JPS62142401A - Dielectric resonator - Google Patents

Abstract

PURPOSE:To reduce height by forming an open end face around one of open end of a through hole and metalizing periphery of the open end of another through hole to conduct to the side face to make it a terminal short-circuit face, and combining adjoining open ends of remaining through holes and conducting them to each other. CONSTITUTION:Two through holes 21 and 22 are formed in a block-like dielectric porcelain 1. Side faces 103 except the top face 101 and bottom face 102, and inner peripheral faces of through holes 21 and 22 are metalized and a conductive film 31 is formed. Then, the open end of one of through holes 21 and 22 that appear on the top face 101, for instance the through hole 21, is made to the terminal side, and an open end face 211 is formed on the top face of the periphery. Further, in the top face 101, the open end of the remaining through hole 22 is made to terminal and the periphery is metalized to conduct to the side face 103, and a conductive film 32 is formed and made to a short- circuit face.

Description

[Detailed description of the invention] ■ Background of the invention Technical field The present invention relates to a dielectric resonator.

Prior art and its problems As a dielectric resonator for constructing a dielectric filter used in car phones, etc., calcium titanate-titanic acid is used as a dielectric resonator, as shown in Figures 3 (a) and (b), for example. A through hole 2 is provided in the center of a dielectric porcelain l formed in a block shape using magnesium or the like, and one side of both surfaces provided with the through hole is an open end surface 11, and the entire surface other than this open end surface 11 and the through hole are It is known that the inner circumferential surface of the hole 2 is metallized to form a conductive film 3 that is electrically conductive to each other to serve as a short-circuit surface.

Such a dielectric resonator is a distributed constant type filter using TEM mode, and its height in the direction of the through hole is 17
4 people (input; resonant wavelength), and in order to lower the height, either increase the dielectric constant (εr) of the material or apply metallization to the open end surface. There was only one.

However, with such conventional methods, there is a limit to how low the height can be made, making it difficult to downsize, and there are obstacles when on-boarding or stacking, so some kind of improvement is required.

II. OBJECTS OF THE INVENTION An object of the present invention is to provide a dielectric resonator whose height can be reduced at the same resonant frequency.

■Disclosure of invention These objects are achieved by the invention described below.

That is, the present invention provides a dielectric resonator in which a plurality of through holes are formed in a block-shaped dielectric ceramic and metallization is applied to the side surface and the inner peripheral surface of the through hole. Form an open end surface around one of the through holes, metallize the periphery of the open end of the other through hole so as to conduct it with the side surface to form a terminal short circuit surface, and combine the adjacent open ends of the remaining through holes to make them conductive to each other. This dielectric resonator is characterized in that it is metallized and connected to form a conductive surface, and the conductive surface and the side surfaces are insulated.

■Specific structure of the invention Hereinafter, a specific configuration of the present invention will be explained in detail.

The dielectric resonator of the present invention has a plurality of (n) through holes formed in a block-shaped dielectric ceramic, and metallization is applied to the side surface and the inner peripheral surface of the through hole. Apply metallization to both sides of the opening as follows.

First, the cases in which the number of through holes n=2 and n=3 will be specifically described, with a focus on how to apply metallization to the top and bottom surfaces.

1) n=2 As shown in FIG. 1, two through holes 21 and 22 are formed in the block-shaped dielectric ceramic 1. and the top surface 101
and the side surface 103 excluding the bottom surface 102 and the through holes 21 and 2
A conductive film 31 is formed by metallizing the inner circumferential surface of 2.

Next, one of the through holes 21 and 22 formed in the upper surface 101, for example, one open end of the through hole 21 is set as a terminal side, and an open end surface 211 is formed on the upper surface around the terminal side. The open end of the remaining through hole 22 is set as the terminal end, and the periphery thereof is metalized to form a conductive film 32 so as to be electrically conductive with the side surface 103, thereby forming a short-circuit surface.

In addition, through holes 21 and 22 formed on the bottom surface 102
A connecting conductive film 33 is formed by metallizing the bottom surfaces so that they are electrically conductive with each other. This conductive film 33 is made not to be electrically connected to the conductive film 31 on the side surface 103. For example, as shown in FIG. 1(d), the entire bottom surface 102 may be metalized to form a conductive film 33, and the insulating band portion 4 may be provided in a portion surrounding the through holes 21 and 22.

By doing this, compared to the conventional dielectric resonator as shown in FIG.
2 things are obtained.

In addition, in the illustration, the open end surface and the short circuit surface formed on the upper surface 101 divide a rectangular block into two rectangular shapes so as to divide the through holes in the arrangement direction. In addition, top surface 10
1 may be divided diagonally into two, one side being an open end surface and the other being a short circuit surface, and the open ends of the through holes 21 and 22 may be located within each surface.

Further, the conductive film 35 on the bottom surface 102 does not need to be short-circuited with the conductive film 33 on the side surface, and the method of division can be changed in various ways.

2) n=3 As shown in FIG. 2, three through holes 21, 22 and 23 are formed in the block-shaped dielectric ceramic 1. Then, the side surface 103 excluding the top surface 101 and the bottom surface 102 and the through hole 21
The inner circumferential surfaces of 22 and 23 are metallized to form a conductive film 34.

Next, one of the through holes 21, 22 and 23 formed in the upper surface 101, for example, the open end of the through hole 21 on the side end side is set as the terminal side, and an open end surface 211 is formed on the upper surface of the peripheral surface.

Further, on the upper surface 101, the remaining through holes 22 and 23 are connected by metallizing the upper surfaces so as to be electrically conductive with each other, thereby forming a conductive film 35. However, this conductive film 35
should not be electrically connected to the conductive film 34 on the side surface 103.
In this case, for example, as shown in FIG. 2(c), a conductive layer 1I35 is provided in an island shape surrounding the through holes 22 and 23.

On the other hand, regarding the through holes 21, 22 and 23 formed in the bottom surface 102, first, the bottom opening end of the through hole 23 on the opposite side to the through hole 21 on the terminal side is the terminal end, and the bottom surface around the through hole 23 is terminated. 102 is metallized so as to be electrically conductive with the conductive film 34 on the side surface 103 to form a conductive film 36 to serve as a short-circuit surface.

In addition, the through holes 21 and 22 are metalized to form a connecting conductive film 37 so as to be electrically conductive with each other, and this conductive film 3
7 is made not to be electrically conductive to the conductive film 34 on the side surface 103 and the conductive film 36 connecting the through hole 23 on the bottom surface 102 and the conductive film 34 on the side surface 103 . In this case, for example, Fig. 2 (
As shown in d), the conductive film 37 may be provided in an island shape,
1) A method of providing an insulating band as shown in the case of n=2 may be used.

By doing this, it is possible to obtain a height and frequency approximately ⅓ compared to the conventional one (FIG. 3).

When n through-holes are formed, the open end of the through-hole located on the - side end side is the terminal side, and the periphery thereof is the open end surface.

Further, one open end of the through hole located on the other side end side is the terminal end, and the periphery thereof is electrically connected to the short circuit surface on the side surface to form a short circuit surface. In this case, when n is an even number, the short circuit surface is formed on the same surface as the open end surface, and when n is an odd number, the short circuit surface is formed on the back surface of the open end surface.

The open ends of adjacent through holes formed in the top and bottom surfaces may be electrically connected to each other on the top and bottom surfaces, and may be insulated from the short-circuit surfaces on the side and bottom surfaces.

By forming n through holes in this manner, it is possible to reduce the height and frequency to approximately 1/n.

Metallization is performed by a method of printing a metal paste, a method of metal plating, a method of metal vapor deposition, or the like.

Further, when an insulating band is provided, a method such as etching, grinding, or a method for providing an insulating band during printing may be selected as appropriate. The metallized film generally has a thickness of about 1 to 30 pm.

Note that the dielectric ceramic is usually a rectangular parallelepiped, but its shape is not particularly limited as long as it can form a plurality of through holes. And its volume is 38~17000mm3
degree.

Usually, about 2 to 5 through holes are formed per hole, and the cross-sectional shape thereof is usually circular, but may be other shapes, and generally has a cross-sectional area of 0.78 to 30 mm2 and a length of about 3 to 40 mm.

Further, the open end surface and the terminal short circuit surface may have a size of about 1/n of the top surface or the bottom surface.

Further, the conductive surfaces between the through holes may generally have a size of about 2/n of the top surface or bottom surface.

Furthermore, a capacitor may be coupled to the antenna side and the terminal side coupled to the transmitter and receiver, or a capacitor may be formed in the through hole.

Alternatively, although the case where all the side surfaces are short-circuited surfaces has been described above, a portion of the side surfaces, for example, a pair of opposing surfaces, may be made into open surfaces.

Various grooves, recesses, etc. can also be formed on the top surface, bottom surface, and side surfaces.

Furthermore, a plurality of these dielectric resonators can be connected in a block to form a band-pass filter, or a band-elimination filter can be integrated therein.

■Specific Effects of the Invention According to the present invention, there is provided a dielectric resonator in which a plurality of through holes are formed in a block-shaped dielectric ceramic and metallization is applied to the side surface and the inner peripheral surface of the through hole. , form an open end surface around one of the open ends of the through hole, metallize around the open end of the other through hole so as to conduct with the side surface to form a short-circuit termination surface, and form a short-circuit end surface around the other open end of the other through hole, and Two through holes are combined and connected by metallization so that they are conductive to each other, and the conductive surface and surrounding area of the connected part is insulated, so the height can be lowered and at the same time it can be used at low frequencies. A dielectric resonator capable of resonance is obtained.

If the number of through holes is n, the height and frequency can be reduced to about 1/n compared to the conventional one.

This allows for miniaturization, onboarding, stacking, etc.

[Brief explanation of drawings]

In FIG. 1, (a) shows the structure of the present invention when there are two through holes. A dielectric resonator perspective view, (b) is a vertical sectional view of (a), (c) is a top view of (a), and (d) is (a)
FIG. In Fig. 2, (a) is a perspective view of the KA dielectric resonator of the present invention when there are three through holes, (b) is a vertical cross-sectional view of (a), and (c) is a top view of (a). Figure, and (d) are (b)
FIG. In FIG. 3, (a) is a perspective view of a conventional dielectric resonator, and (b) is a longitudinal sectional view of (a). Explanation of symbols 1... Dielectric ceramic, 11... Open end surface, 101... Top surface, 102... Bottom surface, 103... Side surface, 2.21, 22.23... Through hole. 3.31, 32, 33, 34, 35, 36°37...
Conductive film, 4... Insulating band part

Claims (1)

[Claims] (1) A dielectric resonator in which a plurality of through holes are formed in a block-shaped dielectric ceramic and metallization is applied to the side surface and the inner peripheral surface of the through hole, and the area around one of the open ends of the through hole is An open end surface is formed in the through hole, the periphery of the open end of the other through hole is metalized so as to be electrically conductive with the side surface, and a termination short-circuit surface is formed, and the adjacent open ends of the remaining through holes are combined so that they are electrically conductive with each other. A dielectric resonator characterized in that it is metallized and connected to form a conductive surface, and the conductive surface and the side surfaces are insulated.