JP2885119B2 - Dielectric filter and antenna duplexer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention
Dielectric filter used in mobile communication devices such as mobile phones
And an antenna duplexer .

[0002]

2. Description of the Related Art FIG. 10 shows a configuration of a conventional dielectric filter using a dielectric block. In the following figures, the dot-filled portions indicate portions where the base of the dielectric block is visible (conductor-less portions).

In this dielectric filter, as shown in FIG. 10, for example, two resonator holes 2 are formed through a pair of opposing end faces of a dielectric block 1. 2, an inner conductor 3, 3 is formed on the inner surface, an outer conductor 4 is formed on the outer surface of the dielectric block 1, and a pair of input / output electrodes 7, 7 are formed at predetermined positions of the outer conductor 4. I have.
Each inner conductor 3 is connected to one of the opening surfaces 1 of each resonator hole 2.
a (hereinafter referred to as an open end face), the inner conductor 3
(Hereinafter, referred to as an inner conductor non-formed portion) is provided, separated (opened) from the outer conductor 4, and the other opening surface 1b
(Hereinafter referred to as a short-circuit side end face), it is conductive (short-circuited) with the outer conductor 4. This dielectric filter is composed of two stages of resonators formed for each of the resonator holes 2, 2, and the resonators are so-called comb-line coupled by the stray capacitance generated in the portion where the inner conductor is not formed. .

In such a configuration, the input / output electrodes 7
8 and the inner conductor 3 corresponding thereto, respectively.
As shown in the figure, an external coupling capacitance Ce is generated, and external coupling is obtained by the external coupling capacitance Ce.

[0005]

By the way, in a filter for obtaining external coupling by the external coupling capacitance Ce as in the above-mentioned conventional example, when the band is wide and strong external coupling is required, the area of the input / output electrode is large. Or increase the distance between the input and output electrodes and the inner conductor by decentering the resonator hole,
Obtain proper outer coupling.

However, in order to obtain a desired external coupling, it is necessary to form input / output electrodes having different shapes and dimensions each time, and there is a problem that standardization of the input / output electrodes is difficult.

Further, there has been a problem that the Qo (no-load Q) of the resonator is reduced by increasing the area of the input / output electrodes or decentering the resonator hole. In addition, increasing the input / output electrode area has a problem that the effective permittivity decreases and the length of the resonator increases.

Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional dielectric filter, without changing the shape and dimensions of the input / output electrodes and without lowering the Qo of the resonator. Another object of the present invention is to provide a dielectric filter and an antenna duplexer which can easily obtain proper external coupling.

[0009]

To achieve the above object, according to the first aspect of the present invention, there is provided a resonance block in which an inner conductor is formed on an inner surface by penetrating between a pair of opposed end surfaces of a dielectric block.
The vessel holes provided in the dielectric filter obtained by forming an outer conductor on the outer surface of the dielectric block including the both end surfaces, said co
The inner conductor of the vibrator hole has an inner conductor non-formed portion near one end face.
Provided, a neighboring resonator holes corresponding to input and output stages of said resonator holes, in parallel with the resonator hole is provided with excitation hole inner conductors are formed on the inner surface, one end face, Also
Is connected to the inner conductor of the excitation hole over the end face and side face.
To form input / output electrodes separated from the outer conductor, and
Externally connected by electromagnetic field coupling with the resonator hole corresponding to the input / output stage
It is characterized by obtaining a bond .

[0010] The invention according to claim 2 is the invention according to claim 1 .
In the dielectric filter, the excitation of the dielectric block is performed.
A part of the formation area of the vibration hole is deleted, and the dielectric block is removed.
The end face is formed in a step shape .

According to a third aspect of the present invention, there is provided a dielectric block.
An inner conductor is formed on the inner surface by penetrating between a pair of opposing end surfaces
Of the resonator hole and the reception filter
A dielectric block including a resonator hole,
Antenna duplexer with an outer conductor formed on the outer surface of the
The inner conductor of the resonator hole has an inner conductor near one end face.
A body non-forming portion is provided, and the cavity
Next to the resonator hole corresponding to the power stage and parallel to the resonator hole
On the inner surface, an excitation hole with an inner conductor formed is provided.
Of the excitation hole, or across the end surface and the side surface.
Forming input / output electrodes that conduct with the inner conductor and separate from the outer conductor,
Electromagnetic field connection between the excitation hole and the resonator hole corresponding to the input / output stage
It is characterized in that an external bond is obtained in some cases.

The invention according to claim 4 is the invention according to claim 3.
In the antenna duplexer, the excitation of the dielectric block is performed.
A part of the formation area of the vibration hole is deleted, and the dielectric block is removed.
The end face is formed in a step shape .

[0013]

[0014]

According to the first or third aspect of the present invention, external coupling of the filter can be obtained by electromagnetic field coupling between the excitation hole and the adjacent resonator hole, and the diameter and the formation position of the excitation hole are changed. In this way, the degree of external coupling can be adjusted and set , and conduction with the inner conductor of the excitation hole can be achieved.
An input / output electrode enables connection to an external circuit (mounting board).
This input / output electrode is not for obtaining external coupling.
In addition, the shape and dimensions can be set arbitrarily. That is, Qo
Shape and dimensions that do not degrade the characteristics such as
You. Also, the input / output electrodes are formed so as to straddle the end face and side face.
End face or side face on which input / output electrodes are formed
Any of the surfaces can be a mounting surface. That is,
Place the dielectric filter or duplexer horizontally and vertically
Can be implemented in either direction.

According to the second or fourth aspect of the present invention, a part of the dielectric block is deleted to thereby enhance the excitation.
Because the length of the vibration hole is adjusted, the diameter of the vibration hole and the formation position
In addition, the degree of external coupling varies depending on the length of the excitation hole.
External coupling adjustment and setting flexibility
Thus, a more appropriate external connection can be obtained.

[0016]

[0017]

[0018]

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing embodiments thereof. In the figure, the same reference numerals are given to parts having the same or corresponding functions and the same functions as those of the conventional example. The following drawings are external perspective views of the dielectric filter as viewed from the open end face side.

FIG. 1 shows the structure of a dielectric filter according to a first embodiment of the present invention.

As shown in FIG. 1, the dielectric filter of this embodiment has a substantially rectangular parallelepiped dielectric block 1 which penetrates a pair of opposing end surfaces and has inner conductors 3 formed on the inner surfaces thereof. Resonator holes 2, 2 and a pair of excitation holes 5,
The outer conductor 4 is formed on substantially the entire outer surface of the dielectric block 1. The excitation holes 5, 5 are the resonator holes 2,
2 and extends over the open-side end surface 1a and one side surface 1c (the upper surface in the figure).
A pair of input / output electrodes 7, 7 are formed to conduct with the inner conductor 3 and separate from the outer conductor 4. That is, the inner conductors 3, 3 of the excitation holes 5, 5 are separated from the outer conductor 4 at the open end face 1a,
The short-circuit side end face 1b is electrically connected to the outer conductor 4.

Further, the inner conductors 3, 3 of the respective resonator holes 2, 2
In the open end face 1a, an inner conductor non-formed portion is provided near the open end face 1a, separated (opened) from the outer conductor 4, and the short-circuit end face 1b
Are electrically connected (short-circuited) with the outer conductor 4, and the resonators formed for each of the resonator holes 2 and 2 are so-called comb-line coupled by the stray capacitance generated in the portion where the inner conductor is not formed.

In this configuration, the excitation hole 5 and the resonator hole 2 adjacent to the excitation hole 5 are electromagnetically coupled, and external coupling between the input and output portions of the dielectric filter is obtained by the electromagnetic field coupling. The input / output electrodes 7, 7 are formed merely for connection to an external circuit.

By changing the inner diameter and the formation position of the excitation hole 5 and changing the distance between the inner conductor 3 of the excitation hole 5 and the inner conductor 3 of the resonator hole 2 adjacent thereto, the degree of external coupling is improved. Can be adjusted and set. In other words, stronger external coupling can be obtained by increasing the inner diameter of the excitation hole 5 or by bringing the excitation hole 5 closer to the resonator hole 2 and reducing the distance between the inner conductors.

In this configuration, since the external coupling is not determined by the shape and dimensions of the input / output electrode 7, the shape and dimensions can be arbitrarily set even when external couplings having different strengths are obtained. 7 can be standardized.
By this standardization, mounting and mounting costs can be reduced, for example, by standardizing the pattern of the mounting board.

Also, since the area of the input / output electrodes can be reduced, the Qo does not decrease due to the large input / output electrodes, and the resonator length does not increase due to the decrease in the effective permittivity. Further, since it is not necessary to largely decenter the resonator hole 2, a decrease in Qo due to the eccentricity of the resonator hole 2 can be suppressed. Therefore, Qo is high and insertion loss is small,
A small-sized dielectric filter having a desired external coupling can be obtained.

The input / output electrodes 7, 7 are connected to the open end face 1.
a and one side surface 1c, and can be mounted on a mounting board with either the open side end surface 1a or the one side surface 1c as a mounting surface. That is, the dielectric filter of this embodiment can be mounted on the mounting board in any of the horizontal and vertical directions.

Next, the structure of a dielectric filter according to a second embodiment of the present invention is shown in FIG.

The dielectric filter according to this embodiment has the structure shown in FIG.
As shown in the figure, the opening side end surface 1a of the dielectric block 1 is formed with a stepped portion on the side of the open side end surface 1a where the excitation holes 5, 5 are formed and the stepped portion 11 is provided. Each input / output electrode 7 is formed so as to straddle the step portion 11 and one side surface 1c which are one opening surface of the excitation hole 5,
It is electrically connected to the inner conductor 3 of the excitation hole 5 and is separated from the outer conductor 4. Other configurations are the same as those shown in FIG. 1 and the description thereof is omitted.

In this configuration, the degree of external coupling due to electromagnetic field coupling between the excitation hole 5 and the resonator hole 2 adjacent to the excitation hole 5 can be adjusted and set by changing the length of the excitation hole 5. In other words, the degree of external coupling can be changed by the diameter and the position of the excitation hole 5 and the length of the excitation hole 5, so that the degree of freedom of adjustment and setting of the external coupling increases, and a more appropriate external coupling can be achieved. Obtainable.

In this embodiment, the step is provided on the open end face 1a side. However, the present invention is not limited to this, and a step may be provided on the short end face 1b.
A step may be provided in 1b.

Next, the structure of a dielectric filter according to a third embodiment of the present invention is shown in FIG.

The dielectric filter according to this embodiment has the structure shown in FIG.
As shown in FIG. 5, a pair of input / output electrodes 7 and 7 which are connected to the inner conductor 3 of the excitation holes 5 and 5 and are separated from the outer conductor 4 across the short-circuit side end face 1b and one side face 1c (the upper face in the figure) Are formed. That is, the inner conductors 3, 3 of the excitation holes 5, 5 are electrically connected to the outer conductor 4 on the open end face 1a, and are separated from the outer conductor 4 on the short-circuited end face 1b. Other configurations are the same as those shown in FIG. 1 and the description thereof is omitted. That is, in the dielectric filter of this embodiment, the input / output electrodes 7 are formed on the short-circuit side end face 1b side, contrary to the one shown in FIG. 1 of the first embodiment.

In this configuration, the influence of the magnetic field is greater on the short-circuit side end face 1b side than on the open-side end face 1a side.
Stronger external coupling (electromagnetic coupling) can be obtained as compared with the first embodiment. Also in this embodiment, the degree of external coupling is adjusted and set by changing the diameter and the formation position of the excitation hole 5 without changing the shape and size of the input / output electrode 7 and the position of the resonator hole 2. Therefore, standardization of the input / output electrode 7 becomes easy, and Qo does not decrease.

In this embodiment, as shown in FIG. 2 of the second embodiment, a step 11 is formed on the end face of the excitation hole 5 forming region.
May be provided to change the length of the excitation hole 5.

In each of the above embodiments, the description has been given of the dielectric filter including two resonators each having two resonator holes. However, the dielectric filter including one or three or more resonators is described. May be.

Next, the structure of an antenna duplexer according to a fourth embodiment of the present invention is shown in FIG.

FIG. 4 shows an antenna duplexer according to this embodiment.
As shown in FIG. 5, five resonator holes 2a, 2b, 2c, 2d, and 2e are formed through a pair of end faces of the dielectric block 1, and the outside of the resonator holes 2a and 2e and the resonator hole are formed. 2
Excitation holes 5a, 5b, 5c are formed between b, 2c,
An inner conductor 3 is formed on the inner surface of each of the resonator holes 2a to 2e and each of the excitation holes 5a, 5b, 5c. An outer conductor 4 is formed on substantially the entire outer surface of the dielectric block 1.
Each excitation hole 5 extends over the open end face 1a and one side face 1c.
Three input / output electrodes 7a, 7b, 7c are formed which are electrically connected to the inner conductors 3a, 5b, 5c and separated from the outer conductor 4.

The inner conductor 3 of each of the excitation holes 5a, 5b, 5c is electrically connected to the outer conductor 4 on the short-circuit side end face 1b. The inner conductor 3 in each of the resonator holes 2a to 2e is separated from the outer conductor 4 by an inner conductor non-formed portion on the open end face 1a side, and is electrically connected to the outer conductor 4 on the short-circuit end face 1b.

With this configuration, a transmission filter (or a reception filter) is formed by the two resonators corresponding to the resonator holes 2a and 2b, and a reception filter is formed by the three resonators corresponding to the resonator holes 2c, 2d and 2e. (Or a transmission filter).

The excitation holes 5a, 5c and the resonator holes 2a, 2e,
The excitation hole 5b and the adjacent resonator holes 2b and 2c are electromagnetically coupled, and external coupling is obtained by the electromagnetic coupling. Each of the input / output electrodes 7a, 7b, 7c is formed simply for connection to an external circuit, and the input / output electrodes 7b between the resonator holes 2b, 2c are used for input / output of a transmission filter and a reception filter. This is a common antenna electrode.

Also in this embodiment, since external coupling is obtained by electromagnetic coupling between the excitation hole 5 and the resonator hole 2 adjacent thereto, the shape and size of the input / output electrode 7 and the size of the resonator hole 2 The degree of external coupling can be adjusted and set by changing the diameter and the formation position of the excitation hole 5 without changing the position. Therefore, standardization of the input / output electrodes 7 is facilitated, Qo is not reduced, and the characteristics can be improved.

It should be noted that also in this embodiment, FIG.
As shown in FIG. 2, the input / output electrode 7 may be formed on the short-circuit side end face 1b. Also, as shown in FIG. 2 of the second embodiment, a step portion 11 is provided on the end face of the excitation hole 5 forming region. The length of the excitation hole 5 may be changed.

In each of the above embodiments, the input / output electrode 7 is formed over the end face and one side face of the dielectric block 1. However, the present invention is not limited to this, and the input / output electrode 7 is formed only on one end face as shown in FIG. Alternatively, it may be formed so as to straddle the end face and the upper and lower side faces as shown in FIG. 6, or may be formed so as to straddle the end face and both side faces orthogonal to each other as shown in FIG. In the dielectric filter shown in FIG.
One of the two surfaces can be mounted on a mounting board as a mounting surface.

Further, in each of the above embodiments, the excitation hole 5 is formed substantially on the center line in the thickness direction of the dielectric block 1, but as shown in FIG. The position of each excitation hole 5 in the vertical direction of the dielectric block 1 is not particularly limited.

Next, the structure of a dielectric filter according to a fifth embodiment of the present invention is shown in FIG.

FIG. 8 shows a dielectric filter according to this embodiment.
As shown in FIG. 1, the open end face 1 on which the input / output electrode 7 is formed
Input / output terminals 20, 20 that are electrically connected to the inner conductor 3 of the excitation holes 5, 5 are drawn out from the side a. I / O terminal 2
Reference numeral 0 denotes a rod-shaped metal, which is inserted into the excitation hole 5 and soldered and attached to the inner conductor 3 or the input / output electrode 7 of the excitation hole 5. Other configurations are the same as those shown in FIG. 1 and the description thereof is omitted. That is, the dielectric filter of this embodiment is obtained by connecting the input / output terminal 20 to the one shown in FIG. 1 of the first embodiment.

The input / output terminal 20 as in this embodiment
When connecting to an external circuit by using, the input / output electrode 7 does not necessarily need to be formed. When the input / output electrode 7 is not formed, the outer conductor 4 at the end face on the insertion side of the input / output terminal 20 or a part of the inner conductor 3 of the excitation hole 5 near the end face is deleted, so that the input / output terminal 20 and the outer conductor 4 Separated.

In this configuration, it is possible to support mounting on a mounting board of a terminal insertion type, and the input / output terminals 20
By bending the dielectric filter horizontally,
Can be mounted in any orientation of vertical and input / output terminal 2
By changing the length of 0, the connection position of the mounting board can be set arbitrarily.

Further, the size of the input / output electrode 7 can be reduced, or the characteristics such as Qo can be further improved without the need to form the input / output electrode 7.

In each of the above-described embodiments other than FIG. 1, the input / output terminal 20 may be inserted into the excitation hole 5 and connected from the end face on the side where the input / output electrode 7 is formed. Further, the shape of the input / output terminal 20, the method of connecting the excitation hole 5 to the inner conductor 3, and the like are not particularly limited, and a metal plate is formed into a curl shape.
It is also possible to use an input / output terminal which is connected to the inner conductor 3 of the excitation hole 5 by pressing.

Next, the structure of a dielectric filter according to a sixth embodiment of the present invention is shown in FIG.

FIG. 9 shows a dielectric filter according to this embodiment.
As shown in FIG. 5, a metal case 30 is covered so as to cover the open end face 1a into which the input / output terminal 20 is inserted, and the metal case 30 is configured to be soldered to the outer conductor 4.
The metal case 30 is formed by punching a predetermined portion so as not to come into contact with a portion where the input / output terminal 20 is led out and the input / output electrode 7. Other configurations are the same as those shown in FIG. 8, and description thereof will be omitted. That is, the dielectric filter of this embodiment is the same as that of the fifth embodiment shown in FIG.
A metal case 30 is attached to the one shown by.
Note that a substrate may be inserted between the open side end surface 1a and the metal case 30.

When this dielectric filter is mounted on a mounting board, the input / output terminals 20, 20 and the protruding portions 30a, 30a, 30a, 30a of the metal case 30 are inserted into the mounting board and mounted.

In this configuration, since the open side end surface 1a is covered with the metal case 30, leakage of an electromagnetic field (electromagnetic field leakage) from the opening of the resonator hole 2 can be reduced.

The mounting of the metal case 30 is performed in the first to fourth
It can be applied to the dielectric filter of the embodiment.

In each of the above embodiments, the shape of the excitation hole 5 is circular in cross section. However, the shape of the excitation hole 5 may be any shape, and may be an ellipse, a rectangle, a triangle, or the like. Good. Also, the shape of the resonator hole 2 is not limited to a circular cross section, and it goes without saying that another shape such as a substantially elliptical shape may be used.

[0058]

[0059]

As described above, according to the dielectric filter and the antenna duplexer of the present invention, the dielectric filter and the antenna duplexer are provided with an excitation hole at the input / output portion, and the excitation hole and the adjacent excitation hole are provided. External coupling can be obtained by electromagnetic coupling with matching resonator holes. By appropriately setting the diameter (inner dimension), forming position, and length of the excitation hole,
By adjusting and setting the degree of outer coupling, an optimal outer coupling can be obtained. Further, since it is not necessary to decenter the resonator hole for adjusting the external coupling, it is possible to suppress a decrease in Qo.

The input / output electrodes are not for obtaining external coupling, and their shapes, dimensions, etc. can be set arbitrarily. That is, the shape and dimensions can be made so as not to deteriorate the characteristics such as Qo, and the input / output electrodes can be standardized, so that the mounting cost and the like can be reduced.

Further, the input / output electrodes can be made smaller than the conventional one, the Qo does not decrease, and the resonator length can be shortened.

[0062]

[0063]

Therefore, according to the present invention, a small dielectric filter and an antenna commonly used which can be easily mounted, have a high Qo, and have an optimum external coupling, which correspond to various mounting forms.
You can get a bowl .

[Brief description of the drawings]

FIG. 1 is an external perspective view of a dielectric filter according to a first embodiment of the present invention.

FIG. 2 is an external perspective view of a dielectric filter according to a second embodiment of the present invention.

FIG. 3 is an external perspective view of a dielectric filter according to a third embodiment of the present invention.

FIG. 4 is an external perspective view of an antenna duplexer according to a fourth embodiment of the present invention.

FIG. 5 is an external perspective view of another dielectric filter according to the present invention.

FIG. 6 is an external perspective view of another dielectric filter according to the present invention.

FIG. 7 is an external perspective view of another dielectric filter according to the present invention.

FIG. 8 is an external perspective view of a dielectric filter according to a fifth embodiment of the present invention.

FIG. 9 is an external perspective view of a dielectric filter according to a sixth embodiment of the present invention.

FIG. 10 is an external perspective view of a conventional dielectric filter.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 dielectric block 2, 2 a to 2 e resonator hole 3 inner conductor 4 outer conductor 5, 5 a to 5 c excitation hole 7, 7 a to 7 c input / output electrode 11 stepped portion 20 input / output terminal 30 metal case

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-163403 (JP, A) JP-A-60-254801 (JP, A) JP-A-62-15901 (JP, A) JP-A-62-163 235801 (JP, A) JP-A-6-140805 (JP, A) JP-A-62-43904 (JP, A) JP-A-6-13201 (JP, U) JP-A-2-143803 (JP, U) Japanese Utility Model 6-38303 (JP, U) Japanese Utility Model 1-105203 (JP, U) Japanese Utility Model 6-41201 (JP, U) Japanese Utility Model Utility Model 60-119103 (JP, U) Japanese Utility Model 5-23603 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01P 1/205 H01P 1/213 H01P 5/08

Claims (4)

(57) [Claims] 1. A resonator hole having an inner conductor formed on an inner surface thereof, penetrating between a pair of opposed end surfaces of a dielectric block,
In a dielectric filter in which an outer conductor is formed on an outer surface of a dielectric block including both end faces, an inner conductor non-formed portion is provided near one end face of the inner conductor of the resonator hole. An excitation hole in which an inner conductor is formed on the inner surface is provided next to the resonator hole corresponding to the input / output stage of the device hole, in parallel with the resonator hole, and straddles one end surface, or the end surface and the side surface. Forming an input / output electrode which is electrically connected to the inner conductor of the excitation hole and separated from the outer conductor, and obtains external coupling by electromagnetic coupling between the excitation hole and a resonator hole corresponding to the input / output stage. Dielectric filter. 2. The dielectric filter according to claim 1, wherein a part of a region of said dielectric block in which said excitation hole is formed is deleted, and an end face of said dielectric block is formed in a stepped shape. 3. A resonator hole forming a transmission filter having an inner conductor formed on an inner surface thereof and a resonator hole forming a reception filter penetrating between a pair of opposing end surfaces of the dielectric block, wherein said both end surfaces are provided. An antenna duplexer having an outer conductor formed on the outer surface of a dielectric block including: an inner conductor non-formed portion is provided near one end surface of the inner conductor of the resonator hole, Next to the resonator hole corresponding to the input / output stage, an excitation hole having an inner conductor formed on the inner surface thereof is provided in parallel with the resonator hole, and one end face, or the end face and the side face, An antenna duplexer, wherein input / output electrodes are formed which are electrically connected to an inner conductor of an excitation hole and separated from an outer conductor, and external coupling is obtained by electromagnetic coupling between the excitation hole and a resonator hole corresponding to the input / output stage. . 4. The antenna duplexer according to claim 3, wherein a part of a region of said dielectric block in which said excitation hole is formed is deleted, and an end face of said dielectric block is formed in a stepped shape.