JP2009188713A - Dielectric resonator and stacked filter using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a product, regarding a dielectric resonator, and to provide a stacked filter that uses the same. <P>SOLUTION: Regarding a dielectric resonator 2 and a stacked filter 1 using the same, the dielectric resonator 2 comprise: a dielectric layer 3; a ground via hole 4 through the dielectric layer 3; an enclosure electrode 5, with one end open, provided to surround the grounding via hole 4 on the principal surface of the dielectric layer 3; and a connecting electrode 6, connecting one end of this enclosure electrode 5 and the via hole 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a dielectric resonator formed by a strip line and a multilayer filter using the dielectric resonator.

  A conventional stripline type dielectric resonator is provided with a transmission line on the main surface of the dielectric layer and a grounding electrode on the back surface of the dielectric layer facing the transmission line. And a dielectric resonator having a resonance frequency corresponding to the distance between the transmission line, the width of the transmission line, and the dielectric constant of the dielectric layer.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP-A-8-78909

  However, in such a dielectric resonator, the ground electrode and the transmission line provided on different main surfaces must face each other through the dielectric layer, and the lower limit of the area occupied by the ground electrode is determined, When a multilayer filter is configured using this, it is necessary to arrange transmission lines on the ground electrode, which makes it difficult to reduce the size of the dielectric resonator and the multilayer filter using the dielectric resonator. .

  Therefore, the present invention aims to solve such problems and to reduce the size of a dielectric resonator and a multilayer filter using the dielectric resonator.

  Therefore, in order to achieve this object, the present invention is configured so that the configuration of the dielectric resonator is such that the dielectric layer, the grounding via hole penetrating the dielectric layer, and the grounding via hole are surrounded on the main surface of the dielectric layer. It is composed of a surrounding electrode provided at one end opening and a connection electrode that connects one end of the surrounding electrode and a via hole.

  With this configuration, the dielectric resonator and the multilayer filter using the dielectric resonator can be reduced in size.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows the structure of a multilayer filter 1, and its basic structure is a multilayer structure in which a plurality of dielectric layers 3 constituting a dielectric resonator 2 made of ceramics are stacked. 1 includes a grounding via hole 4 penetrating through the dielectric layer 3, an enclosing electrode 5 provided at one end so as to surround the end face of the via hole 4, and a connection electrode connecting the one end of the enclosing electrode 5 and the via hole 4. 6 is provided. Further, an input / output electrode 7 and a ground electrode 8 for external connection are provided on the lower surface of the dielectric layer 3 positioned at the lowermost layer. The ground electrode 8 is connected to the lower end of the via hole 4. It is connected to the lower end of the lead-out via hole 9 connected to the open end of the surrounding electrode 5. Further, the dielectric layer 3 provided with no electrode such as the via hole 4 and the surrounding electrode 5 is provided as a protective layer 10 in the uppermost layer.

  Then, by connecting the ground electrode 8 provided on the lower surface of the multilayer filter 1 to the external ground, the surrounding electrode 5 provided on each dielectric layer 3 functions as a one-end short-circuited strip line, and the entire multilayer filter 1 As described above, a filter circuit is configured in which a plurality of surrounding electrodes 5 constituting each one-end short-circuited strip line are coupled.

  That is, the surrounding electrode 5 provided in each dielectric layer 3 is provided concentrically around the via hole 4 that is grounded by the ground electrode 8, so that the inner peripheral end face of the surrounding electrode 5 is the surface of the multilayer filter 1. The via hole 4 that forms the reference ground potential is confronted in the plane between the layers, and one end of the surrounding electrode 5 is connected to the via hole 4 by the connection electrode 6, and as shown in FIG. The adjacent strip lines 12 are coupled by a capacitor 11 by forming regions in which the surrounding electrodes 5 constituting the strip line 12 are opposed to each other in the stacking direction, thereby forming a filter circuit.

  In the conventional strip line structure, as described above, the transmission line and the ground electrode are arranged so as to face each other on the upper and lower main surfaces with the dielectric layer interposed therebetween. In the multilayer filter 1 shown in the drawing, the via hole 4 constituting the reference ground potential is surrounded by the surrounding electrode 5 at one end opening, so that it is enclosed within one main surface of the dielectric layer 3 provided with the surrounding electrode 5. Since the stripline structure in which the electrode 5 is opposed to the reference ground potential is formed, the dielectric resonator 2 can be made smaller than the conventional stripline structure.

  Further, the surrounding electrode 5 has a round shape less than one round because it needs to confront the via hole 4 located in the center and in the plane between the layers.

  The dielectric resonator according to the present invention and the multilayer filter using the dielectric resonator can reduce the size of the product, and are useful in high-frequency circuit applications mainly used in communication equipment and the like.

1 is an exploded perspective view of a multilayer filter showing an embodiment of the present invention. Equivalent circuit diagram of the same multilayer filter

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multilayer filter 2 Dielectric resonator 3 Dielectric layer 4 Grounding via hole 5 Surrounding electrode 6 Connection electrode

Claims (2)

A dielectric layer; a grounding via hole penetrating the dielectric layer; an enclosing electrode having one end opening provided to surround the grounding via hole on a main surface of the dielectric layer; an end of the enclosing electrode; A dielectric resonator comprising a connection electrode for connecting a via hole. A dielectric layer; a grounding via hole provided in the dielectric layer; a surrounding electrode having one end opening provided to surround the grounding via hole in a main surface of the dielectric layer; and one end of the surrounding electrode; A plurality of dielectric resonators each including a connection electrode connecting the via hole, and the first dielectric resonator and the second dielectric resonator are stacked so that the ground via hole is connected in a straight line. The multilayer filter is characterized in that the respective surrounding electrodes are at least partially opposed to each other through the dielectric layer.

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