JPH047904A - Dielectric coaxial resonator and dielectric filter using the resonator - Google Patents

Abstract

PURPOSE:To obtain a desired resonance frequency and to make the filter small by forming a large conductor layer area at other end face of a resonator main body. CONSTITUTION:A silver-metallized conductor layer 17 is formed to one end face 13 of a square dielectric coaxial resonator 11 opposite to an open end face 12, an outer circumferential face 14 and an inner circumferential face 16 of a throughhole 15. Moreover, a conductor layer 18 in continuity with the conductor layer 17 of the inner circumferential face 16 is formed to the open end face 12. Then in order to increase the capacitive component of the dielectric coaxial resonator 11, an insulation plate 19 is placed on the open end face 12 and conductor layers 20 formed on the insulator 19 by high temperature baking are connected electrically.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a dielectric coaxial resonator used in communication equipment such as automobile telephones, personal radios, cordless telephones, etc., and a dielectric filter using the same.

Prior Art A conventional dielectric coaxial resonator was constructed as shown in FIG. In the dielectric coaxial resonator 1, an outer conductor layer 4 and an inner conductor layer 5 are formed by silver metallization on one end surface other than the open end surface 2, the outer peripheral surface, and the entire inner peripheral surface of the through hole 3.

Further, a conductor layer 6 is formed on the open end surface 2 and is electrically connected to the conductor layer 5 on the inner circumference.

Next, a dielectric filter using a conventional dielectric coaxial resonator 1 will be explained with reference to FIG.

A metal center fitting 7 is provided in the through hole 3 of the dielectric coaxial resonator 1.
is inserted and electrically connected to the electrode of the capacitor substrate 18.

Furthermore, electrodes for coupling the dielectric coaxial resonator 1 are formed on the back and front surfaces of the capacitor substrate 8.
An output terminal 9 is connected to these electrodes by solder.

Further, the metal case 10 has a ground terminal 11 and is electrically connected to the outer circumferential conductor 4 of the dielectric coaxial resonator 1 by soldering or the like.

Problems to be Solved by the Invention It is well known that in order to obtain a low resonant frequency in the conventional dielectric coaxial resonator 1, it is formed using a material with a large dielectric constant. In the end, it is difficult to obtain a low resonant frequency using this method. The reality is that we have no choice but to make the shape larger to accommodate this.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a dielectric coaxial resonator which is small in size and has a desired resonant frequency without any reduction in Q.

Means for Solving the Problems and In order to achieve this object, the present invention provides a through hole in the center, and forms a conductive layer on this through hole, one end surface, and the outer peripheral surface] / 4-person dielectric coaxial resonance A conductive layer connected to either the through hole or the conductive layer formed on the outer peripheral surface is formed on the other end face of the container body, an insulating layer is provided on the other end face, and the above-mentioned conductive layer is provided on the upper surface of the insulating layer. This structure includes a conductive layer connected to the conductive layer on the other end surface.

According to this technical means, at the other end face:
Since a large conductive layer area is formed, the desired resonant frequency can be obtained without making the length of the dielectric coaxial resonator unnecessarily long, and the size can be reduced accordingly. There will be no decrease in Q.

Example An embodiment of the present invention will be described with reference to FIG.

A conductor layer 17 made of silver metallization is formed on one end surface 13 of the prismatic dielectric coaxial resonator 11 opposite to the open end surface 12, the outer peripheral surface I4, and the inner peripheral surface 16 of the through hole 15. In addition, the open end surface 12 has a conductor layer 1 on the inner peripheral surface ]6.
A conductor layer 18 is formed which is electrically connected to the conductor layer 7 . Next, in order to increase the capacitance component of the dielectric coaxial resonator 11,
A plate-like insulator 19 is placed on the open end surface 12, and the conductor layer 20 formed on the insulating IF 119 by high-temperature firing is electrically connected to the conductor layer 20. Note that the through hole 15 is
! ! , is blocked by sewing material 19.

Next, FIGS. 2 and 3 show an example in which a dielectric filter is constructed using the dielectric coaxial resonator 11 described above.
This will be explained using figures.

In FIG. 4, two dielectric coaxial resonators 11 are connected on a printed circuit board 21 using a coupling capacitor 22 on the printed circuit board 21. In FIG. This constitutes a dielectric filter. At this time, since the insulator 19 is a white portion, it is bonded to the recessed portion 23 provided on the printed circuit board 21, increasing the degree of adhesion and providing excellent strength.

Next, FIG. 3 will be explained.

FIG. 5 shows a dielectric coaxial resonator 11 of the present invention connected to an alumina substrate 24 without using the conventional center metal fitting 7. In FIG.

That is, 25 is a recessed portion in the alumina substrate 24 for electrically connecting the dielectric coaxial resonator 11. Note that 26 is an electrode with which the conductor layer 20 comes into contact, and 27 is a person and an output terminal.

28 is a comb pattern for resonator coupling.

Effects of the Invention As described above, according to the present invention, an insulating layer is arranged on the open end side of a dielectric coaxial resonator, and a conductive layer provided on the upper surface of this insulating layer is connected to the conductive layer at the open end. As a result, the resonant frequency can be lowered, and it is also small and does not have a drop in Q.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a dielectric coaxial resonator according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a dielectric filter according to one embodiment of the invention, and FIG. 3 is an exploded perspective view of a dielectric filter according to another embodiment of the invention. 4 and 5 are a perspective view and a partially cutaway front view of a conventional dielectric coaxial resonator and a dielectric filter. 11... Dielectric coaxial resonator, 15...
Through hole, 1617, 18.20... Conductor layer, 1
9... Insulator. Name of agent: Patent attorney Shigetaka Awano

Claims (2)

[Claims] (1) A through hole is provided in the dielectric coaxial resonator, and a dielectric layer is formed on the through hole, one end surface, and the outer peripheral surface. a dielectric layer connected to one of the dielectric layers formed on the surface, an insulating layer provided on the other end surface, and a conductive layer connected to the dielectric layer on the other end surface on the upper surface of the insulating layer; A dielectric coaxial resonator with (2) A dielectric filter in which a plurality of dielectric coaxial resonators according to claim (1) are capacitively coupled by a capacitor.