JPH0626304U - Dielectric resonator - Google Patents

Abstract

(57) [Summary] [Object] To provide a dielectric resonator which is easy to manufacture and has a short axial length. A dielectric resonator (10) includes a dielectric block (1), a through hole (2) having openings at the open end face and the short-circuited end face of the dielectric block (1), an outer periphery of the dielectric block (1) and an open end face side. A groove 3 provided between the openings of the through holes 2,
The inner conductor 4 is formed on the inner surfaces of the through hole 2 and the groove 3 and is electrically connected to each other, and the outer conductor 5 is formed on the outer peripheral surface of the dielectric block 1 excluding the open end surface. Further, the flat portion x between the groove 3 and the outer periphery of the dielectric block 1 is made to project more than the flat portion y between the opening of the through hole 2 and the groove 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dielectric resonator used in a dielectric filter or a resonance circuit.

[0002]

[Prior art]

 The dielectric resonator is used as a high-frequency filter for a communication device or the like, as a single unit, in a resonator circuit portion of a high-frequency oscillation circuit, and in series.

In the conventional dielectric resonator, as a means for shortening the axial length (length of the dielectric resonator), the inner conductor is connected around the through hole opening of the open end face of the dielectric resonator. It is already known to provide a groove formed with a conductor (JP-A-58-108801, JP-A-3-190304, JP-A-3-292001).

FIG. 6 shows a dielectric resonator disclosed in JP-A-3-190304.

In the figure, 60 is a dielectric resonator, 61 is a dielectric block, 62 is a through hole, 63 is a groove formed on the open end face of the dielectric block, and 64 is an inner conductor. , 65 are outer conductors.

The inner conductor 64 described above is formed so as to extend to the inner surface of the groove 63 via the inner surface of the through hole 62 and a part of the open end surface a side.

Considering the method of manufacturing the resonator 60, first, in forming the block 61 of the dielectric ceramic, when the powder of the dielectric ceramic material is pressed, the through hole 62, Grooves 63 are formed and sintered.

Next, the entire dielectric block 61 is immersed in Ag paste, the thickness of the coating film is adjusted with a centrifuge or the like, and drying / baking is performed, so that the entire circumference surface of the dielectric block 61 is covered with a conductor. To form.

Next, in order to remove the conductor film deposited on the open end face a side, the open end face a is removed by polishing. By this removal, the inner conductor 64 on the inner surface of the through hole 62 and the inner conductor 64 on the inner surface of the groove 63 are separated from each other.

Next, on the open end surface a of the dielectric block 61, in order to connect the divided inner conductors 64, 64 between the opening of the through hole 62 and the groove 63, a Ag paste is used as a thick film printing method. The conductor film 66 is applied and baked by, for example, to obtain the dielectric resonator 60.

As another manufacturing method, before the dielectric block 61 is dipped in the bath of Ag paste, the groove 63 and the outer periphery of the dielectric block 61 are formed to form the open end surface a of the dielectric block 61. A resist film is applied between and.

Next, the dielectric block 61 is dipped in a bath of Ag paste, and the thickness of the conductor film attached to the entire surface of the dielectric block 61 is controlled, dried and baked. The resist film disappears during this baking.

[0013]

[Issues to be devised]

 Whichever method is used to manufacture the dielectric resonator, the connection between the inner conductor 64 in the through hole 62 and the inner conductor 64 on the inner surface of the groove 63 may be reconnected via the conductor film 66 after polishing, or The dielectric resonator has a complicated manufacturing process because it requires treatment of the open end face such as coating a resist film so that the open end face is formed.

The present invention has been devised in view of the above problems, and an object thereof is to provide a dielectric resonator which is easy to manufacture and has a short axial length. .

Still another object is to provide a dielectric resonator in which an input / output capacitor and a temperature-compensated capacitor can be easily assembled.

[0016]

[Means for Solving the Problems]

 The present invention provides a prismatic dielectric block having through holes having openings at both end surfaces, a groove provided around one end surface of the dielectric block around the opening of the through hole, and a groove extending from the inner wall of the through hole. In a dielectric resonator consisting of an inner conductor formed over the inner surface of the dielectric block and an outer conductor formed on the outer peripheral surface of the dielectric block excluding one end surface of the dielectric block, one end surface of the dielectric block surrounds the opening of the through hole. The area enclosed between the groove and the groove is recessed inward.

Further, in the dielectric resonator, the capacitor is arranged in a region sandwiched between the opening of the through hole and the groove on one end surface of the dielectric block.

[0018]

[Action]

 As described above, since the groove with the inner conductor formed is formed around the opening of the through-hole on the open end face side of the dielectric resonator, the dielectric resonator can be used for a certain resonance frequency. The axial length of the body resonator can be shortened, and a compact dielectric resonator can be achieved. In addition, since the region surrounded by the opening of the through hole and the groove is recessed inward from between the groove and the outer periphery of the dielectric block, in the method of manufacturing the dielectric block, the entire surface of the dielectric block is It can be easily manufactured by forming a conductor film on the substrate and then polishing between the protruding groove and the outer periphery of the dielectric block.

Further, since the open end face is further recessed between the through hole and the groove through which the inner conductor extends, the recessed portion has a temperature that cancels a change in capacitance due to a temperature change in the resonator. The degree compensation capacitor and the capacitor for input / output capacitance when a filter is composed of multiple resonators can be easily arranged without changing the structure of the dielectric block.

[0020]

EXAMPLES Hereinafter, the dielectric resonator of the present invention will be described in detail with reference to the drawings. FIG. 1 is an external perspective view of a dielectric resonator of the present invention, and FIG. 2 is a sectional view of the dielectric resonator. In FIG. 2, capacitors arranged in the dielectric resonator are also shown.

In the figure, a dielectric resonator 10 includes a dielectric block 1, a through hole 2, a groove 3 formed on a peripheral surface of the through hole 2 for shortening an axial length, a through hole 2 and a groove 3. The inner conductor 4 is formed on the inner surface of the dielectric block 1, and the outer conductor 5 is formed on the entire peripheral surface of the dielectric block 1 excluding the open end surface a.

The dielectric block 1 is made of a substantially rectangular parallelepiped or columnar dielectric ceramic, and a cylindrical through hole 2 is formed so as to open at an open end face a and a short-circuited end face b of the dielectric block 1 facing each other. ing. Further, on the open end face a side of the dielectric block 1, a groove 3 having a predetermined depth is formed around the through hole 2. Further, the plane portion x between the groove 3 and the outer periphery of the dielectric block 1 projects by Δd from the region between the through hole 2 and the groove 3 (hereinafter referred to as the plane portion y). That is, the flat surface portion y between the through hole 2 and the groove 3 is recessed inward from the open end surface a.

The inner conductor 4 is made of a metal conductor film such as Ag or Cu, and is formed on the inner surface of the through hole 2, the flat surface portion y between the through hole 2 and the groove 3 and the inner surface of the groove 3. .

The outer conductor 5 is made of a metal conductor film such as Ag or Cu, and excludes the flat surface portion x between the groove 3 on the open end face a side of the dielectric block 1 and the outer periphery of the dielectric block 1. It is formed on the short-circuit end face b where the four side faces and the through hole 2 are open. As a result, the inner conductor 4 and the outer conductor 5 are connected at the short-circuited end face b of the dielectric block 1.

A connection terminal (not shown) connected to the inner conductor 4 is joined to such a dielectric resonator 10 and is joined to a predetermined printed wiring board (not shown).

When a plurality of the above-described dielectric resonators 10 are joined to form a dielectric filter, the dielectric resonator 10 through which signals are input / output, the flat portion y described above, and the input / output capacitor The spacer 6 can be arranged between the inner conductor 4 and the connection terminal. At this time, since the flat portion y is recessed more than the flat portion x on the side of the open end face a 1, it can be easily assembled through the solder. Further, instead of the input capacitor 6, the temperature compensation type capacitor 6 may be arranged in order to cancel the change of the electrostatic capacitance due to the temperature change of the dielectric resonator 10.

As described above, in the dielectric resonator 10 of the present invention, the groove 3 having a predetermined depth is formed on the side of the open end face a where the through hole 2 opens, and the inside of the groove 3 extends from the through hole 2 to the inner surface of the groove 3. Since the conductor 4 is formed, the actual distance of the inner conductor 4 increases and the resonance frequency decreases, so that the length of the dielectric resonator 10 (the penetrating direction of the through hole) can be shortened and the size of the small size can be reduced. The dielectric resonator 10 can be achieved.

Further, the input / output capacitor 6 can be easily arranged in the flat portion y which is recessed by one step on the open end face a side of the dielectric block 1.

The dielectric resonator 10 described above is manufactured by the manufacturing method shown in FIGS.

First, as shown in FIG. 3, the dielectric block 1 is formed. At this time, a rectangular parallelepiped or columnar dielectric block having the through holes 2 and the grooves 3 is molded and sintered by powder pressing of the dielectric material, injection molding of the dielectric material, or the like.

Here, what is important is that the flat portion y between the through hole 2 and the groove 3 on the open end face a of the sintered dielectric block 1, the groove 3 and the outer periphery of the dielectric block 1 are formed. The difference Δd 'with the flat portion x ′ between the two is slightly larger than the difference Δd ′ of the finished dielectric block 1.

Next, as shown in FIG. 4, a conductor film 7 of Ag or Cu is formed on the entire surface of the above-mentioned dielectric block 1 by a plating method, a paste immersion method, or a baking method. The conductor film 7 has a thickness of about 10 μm.

Next, as shown in FIG. 5, the surface to be the open end surface a of the dielectric block 1 is polished. In this polishing process, the dielectric resonator 10 is polished by a predetermined grinding amount ΔT (Δd′−Δd) corresponding to the resonance frequency of the dielectric resonator 10. As a result, the conductor film 7 is removed between the groove 3 and the outer periphery of the dielectric block 1 to form the flat portion x where the dielectric block 1 is exposed, and the inner conductor 4 is formed on the open end face a side. And the outer conductor 5 are separated.

In the dielectric resonator 10 manufactured as described above, even if the polishing step is performed in FIG. 4, the flat portion y between the through hole 2 and the groove 3 has the flat portion y of the groove 3 and the dielectric block 1. Since the inner conductor 4 adhered to the flat portion y is not removed because it is recessed as compared with the flat portion x with the outer periphery, the through hole 2 is not formed in the post process as in the conventional case. Since it is not necessary to form the conductor film 66 for connecting the inner conductor of FIG. 6 and the inner conductor of the inner surface of the groove 3, the manufacturing method is extremely simple.

As described above, in the dielectric resonator 10 of the present invention, structurally, the groove 3 is formed around the opening on the open end face a side of the through hole 2, and the groove is formed from the inner surface of the through hole 2. Since the inner conductor 4 is formed over the inner surface of the dielectric resonator 10, the resonance frequency of the resonator is lowered, and the dielectric resonator 10 has a shorter axial length (height of the dielectric block 1) with respect to a predetermined resonance frequency. Is achieved.

Further, the flat portion x between the groove 3 and the outer periphery of the dielectric block 1 is projected more than the flat portion y between the through hole 2 and the groove 3, and the capacitor is placed in the depressed flat portion y. It is easy to arrange such things.

Furthermore, in the manufacturing method, since the flat portion x 1 between the groove 3 and the outer periphery of the dielectric block 1 projects more than the flat portion y between the through hole 2 and the groove 3, the dielectric block 1 can be easily manufactured by forming the conductor film 7 on the entire peripheral surface of No. 1 and grinding the open end surface a side.

In the above-described embodiment, the groove 3 is formed in an annular shape around the opening of the through hole 2 and the dielectric block 1 is a rectangular parallelepiped. However, the groove 3 is formed around the opening of the through hole 2. It may be provided in a rectangular shape, or the dielectric block may be cylindrical.

Further, in the embodiment, one through hole is formed in a single dielectric block to form one resonator. However, assuming a dielectric filter in which a plurality of resonators are connected in series. Alternatively, a plurality of resonators may be formed by forming a plurality of through holes and grooves around the through holes in the horizontally long dielectric block.

[0040]

[Effect of device]

 As described above, in the present invention, the open end face between the groove provided for shortening the axial length of the dielectric resonator and the outer circumference of the dielectric block is projected more than between the opening of the through hole and the groove. As a result, a conductor film is applied to the entire circumference of the dielectric block, and it is manufactured only by the grinding process on the open end face side. Therefore, the manufacturing method is easy, and the miniaturized dielectric resonator with a short axial length is used. Becomes

Further, when the input / output capacitor and the temperature compensation type capacitor are attached to the inner conductor of the dielectric resonator, they can be easily arranged without using a special positioning jig.

[Brief description of drawings]

FIG. 1 is a perspective view of a dielectric resonator of the present invention.

FIG. 2 is a sectional view of a dielectric resonator.

FIG. 3 is a cross-sectional view illustrating a method of manufacturing the dielectric resonator of the present invention.

FIG. 4 is a cross-sectional view for explaining a method of manufacturing a dielectric resonator according to the present invention.

FIG. 5 is a cross-sectional view for explaining a method of manufacturing a dielectric resonator according to the present invention.

FIG. 6 is a schematic sectional view of a conventional dielectric resonator.

[Explanation of symbols]

 10 ... Dielectric resonator 1 ... Dielectric block 2 ... Through hole 3 ... Groove 4 ... Inner conductor 5 ... Outer conductor 6 ... Capacitor x・ ・ ・ Flat part y ・ ・ ・ Flat part

Claims (2)

[Scope of utility model registration request] 1. A prismatic dielectric block having through holes having openings at both end surfaces, a groove provided around one end surface of the dielectric block around the opening of the through hole, and an inner wall of the through hole. A dielectric resonator comprising an inner conductor formed over an inner surface of a groove and an outer conductor formed on an outer peripheral surface excluding one end surface of the dielectric block, wherein an opening of a through hole is formed at one end surface of the dielectric block. A dielectric resonator characterized in that a region surrounded by a periphery and a groove is recessed inward. 2. The dielectric resonator according to claim 1, wherein a capacitor is arranged in a region sandwiched between the opening of the through hole and the groove on one end surface of the dielectric block.