JP2780591B2 - Dielectric filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric filter mounted on a communication device such as a portable telephone or a radio telephone.

[0002]

2. Description of the Related Art A conventional dielectric filter will be described below.

FIG. 27 is a perspective view showing a conventional dielectric filter. Numerals 1 and 2 are provided with through holes 1b and 2b in dielectric substrates 1a and 2a made of a dielectric material, and outer conductors 1c and 2c, through holes 1b and 2b are provided on the outer periphery of the dielectric substrates 1a and 2a.
2b, inner conductors 1d and 2d, outer conductors 1c and 2c and inner conductor 1
a dielectric resonator composed of connecting conductors 1e and 2e for connecting d and 2d, and 5 is a dielectric substrate (alumina substrate or the like)
A coupling substrate on which conductors 5a, 5b, 5c and 5d are formed to realize input / output coupling capacitance (between 5a and 5c, 5b and 5d) and inter-stage coupling capacitance (between 5a and 5b). FIG. 28A is a front view of a coupling substrate of the conventional dielectric filter, and FIG. 28B is a rear view of the coupling substrate of the conventional dielectric filter. Reference numerals 6 and 7 denote central conductors for electrically and mechanically connecting the inner conductors 1d and 2d and the coupling substrate 5. Reference numerals 8 and 9 denote input / output terminals, which are conductors 5c and 5 of the coupling board 5.
d is electrically and mechanically connected by soldering or the like.

[0004]

However, in the above-described conventional configuration, the coupling substrate 5, the center conductors 6, 7, the input / output terminals 8, 9 and the like are required, and the size of the dielectric filter can be reduced. However, there are problems that the number of parts is large, man-hours are required, and mass productivity is poor.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a dielectric filter which can reduce the number of parts in addition to miniaturization and is excellent in mass productivity.

[0006]

To achieve this object, according to the first aspect of the present invention, a corner having a step in a through hole is provided.
An inner conductor, an outer conductor, and a connecting conductor are provided on the inner side surface and the outer side surface of the pillar-shaped dielectric substrate, and on one end surface, and an open end is provided on the other end surface. The inter-stage coupling electrode and the joining electrode that are not in contact with the outer conductor by providing the notches continuously on the outer surface of
A pair of dielectric resonators was provided, and the inter-stage coupling electrodes of the pair of dielectric resonators were electrically connected. According to a second aspect of the present invention, in the first aspect, the interstage coupling
Electrodes and connecting electrodes are on the same outer surface of the dielectric substrate
Not provided. In the invention according to claim 3 , the dielectric material
The base is a square pole, and one side of the dielectric base and its opposite
Notches and other notches on each side
Connection electrode and connection in the section and other notch respectively
Electrodes and pass the other cutouts to the two outer surfaces.
Was provided. In the invention according to claim 4, in claim 1 to 3
In this case, a dielectric substrate having a roughened surface was used . Claim 5
In the invention according to claim 4, the surface of the dielectric substrate according to claim 4 is provided.
The roughness was 5 to 9 μm . In the invention according to claim 6, the contract
In claim 4, an etching treatment is performed on the surface of the dielectric substrate.
And facilities. In the invention according to claim 7, in claim 2 or 3 , a step is provided in the through hole of the dielectric substrate . According to an eighth aspect of the present invention, in the first to third aspects, the conductive material on the circuit board is provided.
The membrane and the bonding electrode were directly bonded . According to a ninth aspect of the present invention, in any one of the first to third aspects, the semiconductor device is provided on the dielectric substrate.
Each conductor and electrode had a multilayer structure . In the invention according to claim 10, the first dielectric member having a pair of inter-step coupling electrodes is formed.
A shaker and a pair according to any one of claims 1 to 3.
, And the first dielectric resonator is interposed therebetween.
A second dielectric resonator disposed useless, the first dielectric co
A second dielectric material is applied to each of the pair of interstage coupling electrodes of the vibrator.
The interstage coupling electrodes of the vibrator were electrically connected .

[0007]

According to the first aspect of the present invention, the coupling board and the center conductor can be omitted, and the interstage coupling electrode is not surrounded on all sides by the outer conductor. And the length of the dielectric filter can be reduced , and in one notch
Can be provided with an inter-stage coupling electrode and a connection electrode . According to the invention of claim 2, a plurality of dielectric resonators
In a dielectric filter with
It can be arranged on a joint surface such as a circuit board of a body filter . According to the third aspect of the present invention, a plurality of dielectrics
In the dielectric filter to which the vibration
It can be arranged on the side of the dielectric filter. Further
In addition, the electrode for inter-stage coupling and the electrode for connection should be formed separately
Before forming the electrodes in close proximity
The formation of each electrode is facilitated, the productivity is improved, and
Easy work when joining dielectric resonators to each other
And the connection electrodes and the predetermined on the circuit board etc.
The outer conductor and the connecting electrode when electrically connecting the electrode
Can be prevented from joining . According to the invention of claim 4,
A relatively small bonding area between the interstage coupling electrode and the dielectric substrate
Bonding strength can be increased . According to the invention of claim 5,
By setting the surface roughness of the dielectric substrate to 5 μm or more,
To improve the bonding strength between the dielectric substrate and each conductive film.
And 9 μm or less,
Deterioration of the film characteristics of the conductive film can be prevented . According to the invention as set forth in claim 6, there is a change in adhesion to the surface of the dielectric substrate.
The substance can be removed . According to the invention according to claim 7, the length of the dielectric resonator can be shortened.
In particular, the capacitance between the connection electrode and the inner conductor can be increased . The invention according to claim 8 reduces the number of parts.
Can be done . The invention according to claim 9, each
The versatility of conductors and electrodes can be expanded . Claim 1
By the invention according to 0, the amount of attenuation can be increased .

[0008]

(Embodiment 1) FIGS. 1 and 2 are a perspective view and an exploded perspective view, respectively, showing a dielectric filter according to a first embodiment of the present invention. 1 and 2, 11, 12
Are dielectric resonators. Hereinafter, the structure of the dielectric resonator will be described using the dielectric resonator 11. B
_{aO-TiO 2 -Nd 2 O 3} , BaO-TiO 2, ZrO 2
A through hole 11 is formed in a dielectric substrate 11a made of a dielectric material such as —SnO ₂ —TiO ₂ , BaO—Sm ₂ O ₃ —TiO _2.
b is provided. At this time, the outer shape of the dielectric substrate 11a is square, and the through-hole 11b is formed in a cylindrical shape in cross section.
An outer conductor 11c is provided on an outer surface of the dielectric substrate 11a, and an inner conductor 11c is provided on an inner surface forming the through hole 11b.
d is provided. The outer conductor 11c and the inner conductor 11d are connected by a connecting conductor 11e provided on one end surface. A cutout portion 11k is provided on the open end 11j side of each of the outer surfaces 11i and 11h of the four outer surfaces of the dielectric substrate 11a so that the dielectric substrate 11a is exposed. Notch 1 provided on outer side surface 11i
Within 1k, there is provided an inter-stage coupling electrode 11f formed so as not to be in contact with other conductors.
An electrode 11g for input / output coupling, which is similarly formed so as not to be in contact with other conductors, is provided in the notch 11k provided in the above.

The dielectric resonator 12 has substantially the same configuration as the dielectric resonator 11. That is, the dielectric substrate 12a,
Through hole 12b, outer conductor 12c, inner conductor 12d, connecting conductor 12e, interstage coupling electrode 12f, input / output coupling electrode 12g, outer surface 12h, outer surface 12i, open end 12j,
The cutout 12k is formed. The portions of the dielectric resonator 11 and the dielectric resonator 12 corresponding to the alphabets (for example, the dielectric base 11a and the dielectric base 12a) have substantially the same configuration. It was described as almost the same configuration,
As can be seen from FIG. 2, the dielectric resonator 11 and the dielectric resonator 12 have a mirror-symmetrical relationship with each other. Therefore, the position where the electrodes 11f and 11g are formed
Attention should be paid to the formation positions of f and 12g.

When the dielectric resonator 11 and the dielectric resonator 12 are joined to each other with cream solder or the like while the electrodes 11f and 12f are opposed to each other, the electrodes 11g and 12g face the same plane. Has become. This is because these dielectric resonators have a mirror-symmetric relationship with each other as described above.

The outer conductors 11c and 12c and the inner conductor 11
d, 12d, connecting conductors 11e, 12e, electrodes 11f, 1
2f, each of the electrodes 11g and 12g (hereinafter, these films are collectively referred to as conductor films) are each formed of a thin film made of a conductive material such as copper or silver, and formed to have a thickness of about 5 μm. Is done. In this embodiment, the conductor film is composed of one layer, but may be composed of two or more layers. Further, the film thickness is 5
The thickness is about μm, but the film thickness must be appropriately determined according to the conditions of use of the dielectric filter and the like.

Further, in the first embodiment, the electrodes 11g, 12g
Although the shapes of g and the electrodes 11f and 12f are rectangular, they may be circular, elliptical, polygonal, or any other shape.

FIG. 3 is a circuit diagram showing an equivalent circuit of the dielectric filter according to the first embodiment of the present invention. In FIG. 3, reference numeral 13 denotes an equivalent circuit of the dielectric resonator 11;
Reference numeral 4 denotes an equivalent circuit of the dielectric resonator 12. C1 indicates the capacitance between the electrode 11g and the inner conductor 11d, and C3
Indicates the capacitance between the electrode 12g and the inner conductor 12d. C
Reference numeral 2 denotes a combined capacitance of the capacitance between the electrode 11f and the electrode 11d and the capacitance between the electrode 12f and the inner conductor 12d. As can be seen, the dielectric filter of this embodiment has a very simple structure and can be miniaturized. Specifically, the central conductor and the dielectric substrate are not required in this embodiment, and the configuration is simplified, and as a result, the size can be reduced by about 50%.

FIG. 4 is a perspective view showing a state in which the dielectric filter according to the first embodiment of the present invention is mounted on a substrate. In FIG. 4, reference numeral 15 denotes a printed circuit board made of an insulating material such as glass or epoxy resin, reference numerals 16 and 17 denote input / output lines formed on the printed circuit board 15, and reference numeral 18 denotes a printed circuit board similarly formed on the printed circuit board 15. It is a ground line. The input / output line 16 has an electrode 11g of the dielectric resonator 11
Are joined by solder 19, and the electrode 12 g of the dielectric resonator 12 is joined to the input / output line 17 by solder 20. Further, the outer conductors 11c and 12c of the dielectric resonators 11 and 12 are joined to the ground line 18 by solder 21. The input / output lines 16, 17 and the ground line 18 are A
A conductive paste such as a g paste is applied on the printed circuit board 15 in a predetermined shape, and is formed by baking.

FIG. 5 is a graph showing the attenuation characteristics of the first embodiment and the conventional example. In FIG. 5, A shows the characteristic curve of this embodiment, and B shows the characteristic curve of the conventional example. FIG.
As can be seen from the graph, the characteristic curve A of the present embodiment has poles A1 and A2 in the low band and the high band, respectively. This is because, as shown by the equivalent circuit shown in FIG. 3, some electromagnetic field coupling M occurs between the stages in addition to the capacitive coupling. On the other hand, in the conventional example, no pole is formed on the characteristic curve.

A method of manufacturing the dielectric filter having the above-described configuration will be described below.

First, the raw materials (BaO, TiO ₂ , Nd ₂ O ₃
) Are mixed in predetermined amounts, and this mixture is mixed using a mill or the like. Next, the mixture is granulated by adjusting the particle size and adding a binder using a spray dryer or the like. Next, the granulated product is formed into a predetermined shape by using a dry press, and the formed product is sintered in a firing furnace at a temperature of 1300 ° C. to 1400 ° C. to form a cylindrical dielectric substrate 11 as shown in FIG.
Prepare a. Next, a conductor film is formed on the dielectric substrate 11a. First, in the case of forming a conductive film, there are various forming methods.

First, as a first method, a case where copper is used as a material forming a conductive film will be described. Dielectric substrate 11
The surface of a is roughened by a barrel polisher or a blasting device, and thereafter, the dielectric substrate 11a is subjected to an etching treatment to adjust the surface roughness of the dielectric substrate 11a to about 5 μm to 9 μm. At this time, for example, HF-
HNO ₂ type is used. Next, after the entire surface of the dielectric substrate 11a is subjected to a sensitizing treatment using stannous chloride or the like, palladium as a catalytic metal is attached to the entire surface.
Next, as shown in FIG. 7, a resist film 23 is formed on a part of the dielectric substrate 11a. That is, the resist film 23 is formed in a portion of the dielectric substrate 11a where the conductor film should not adhere (a portion to be the cutout 11k and the open end 11j in the future). The resist film 23 is formed by applying a resist ink on the dielectric substrate 11a using a printing technique or the like, and drying and curing the applied resist ink. Next, a thin first copper film is formed on the dielectric substrate 11a thus processed by using the electroless copper plating method. At this time, the first copper film is selectively formed only on the portion where the resist film 23 is not formed. Next, a second copper film is laminated on the first copper film by electrolytic copper plating to form a conductor film. At this time, the conductor film is formed to have a thickness of about 5 μm. Finally, the resist film 23 is dissolved with a solvent or the like, and the dielectric resonator 11 (or 1) shown in FIGS.
2) is prepared. In this manufacturing method, the resist film 23 is used.
Is formed by applying a resist ink to a predetermined position on the dielectric substrate 11a by a printing technique and then drying and curing the resist ink, but there is also a method using a photosensitive resist as the resist. That is, a catalytic metal such as palladium is applied to the dielectric substrate 1.
After adhering to 1a, a photosensitive resist is applied to the entire surface of the dielectric substrate 11a, and is exposed to cure only a predetermined portion of the photosensitive resist. Then, a portion where the photosensitive resist has not been cured may be washed away with a developer to form a resist film 23 as shown in FIG.

Next, another method for forming a conductive film will be described. First, a conductor film 24 is formed on the entire surface of the dielectric substrate 11a as shown in FIG. At this time, as the conductor film 24, copper may be formed in a two-layer structure as described above. Alternatively, the conductor film 24 may be formed on the entire surface of the dielectric substrate 11a by printing an Ag paste on the entire surface of the dielectric substrate 11a and performing a heat treatment at a temperature of 800 ° C. to 900 ° C. after drying. . Next, as shown in FIG. 9, a resist film 25 is formed on the conductor film 24 in a predetermined shape. The method of forming the resist film 25 is the same as the above-described example. A resist film 25 is formed on portions to be left as conductors and electrodes, and unnecessary portions of the conductive film 24 are removed from the dielectric substrate 11a by using an etching technique such as chemical etching or dry etching. The resonator 11 (or 12) is formed.

As a further method, a conductor film 24 is formed on the entire surface of the dielectric substrate 11a as shown in FIG. The dielectric resonator 11 (or 12) shown in FIG.

The dielectric resonators 11 configured as described above,
The electrodes 11f and 12f are joined so that the electrodes 11f and 12f face each other, and the outer conductor 11c and the outer conductor 12c are joined by cream solder or the like, and the electrodes 11f and 12f are respectively joined by a joining material such as cream solder.

Next, an application example of (Embodiment 1) will be described. 10 and 11 are a perspective view and an exploded perspective view, respectively, showing a dielectric filter according to an application example of the first embodiment of the present invention.

In FIGS. 10 and 11, reference numerals 26 and 27 denote dielectric resonators, respectively. The dielectric resonators 26 and 27 have substantially the same structures as those shown in FIGS. ing. First, the dielectric resonator 26 will be described. Reference numeral 26a denotes a dielectric substrate made of a dielectric material, and the dielectric substrate 26a has a rectangular outer shape. Further, a through hole is provided in the dielectric substrate 26a, and the through hole is a rectangular hole 26b formed on the open end side.
And a cylindrical hole 26c connected to the hole 26b. In the dielectric resonator shown in FIGS. 1 and 2, the through-hole has the same diameter from the open end to the connection end, but in another embodiment, a step is provided in the through-hole. The thing becomes the feature. With this configuration, the hole 26b
Since the inner conductor 26d formed therein can be formed large,
The input / output coupling capacitance between the input / output coupling electrode 26e and the inner conductor 26d can be increased, and the interstage coupling capacitance between the interstage coupling electrode 26f and the inner conductor 26d can be increased. A broadband dielectric filter can be manufactured. Similarly, the dielectric resonator 27 is
A through hole is formed by connecting a square hole 27b and a cylindrical hole 27c to a. By providing an inner conductor 27d in this through hole, the input / output coupling capacity between the electrode 27e and the inner conductor 27d is increased. As well as the electrode 27f
And a large inter-stage coupling capacitance between the inner conductor 27d and the inner conductor 27d.

The rest of the configuration is the same as that shown in FIGS. (Embodiment 2) FIGS. 12 and 13 show a second embodiment of the present invention, respectively.
It is the perspective view and the exploded perspective view which show the dielectric filter in the Example of FIG. 12 and 13, reference numerals 28 and 29 denote dielectric resonators, respectively. Hereinafter, the structure of the dielectric resonator will be described using the dielectric resonator. BaO
—TiO ₂ —Nd ₂ O ₃ , BaO—TiO ₂ , ZrO ₂ —S
A through hole 28b is provided in a dielectric substrate 28a made of a dielectric material such as nO ₂ —TiO ₂ or BaO—Sm ₂ O ₃ —TiO ₂ . At this time, the outer shape of the dielectric substrate 28a is rectangular, and the through-hole 28b is formed in a cylindrical shape in cross section. An outer conductor 28c is provided on an outer surface of the dielectric base 28a, and an inner conductor 28d is provided on an inner surface forming the through hole 28b. The outer conductor 28c and the inner conductor 28d are connected by a connecting conductor 28e provided on one end surface. A cutout 28k is provided on the open end 28j of the outer surface 28h of the four outer surfaces of the dielectric substrate 28a so that the dielectric substrate 28a is exposed. Further, in the cutout portion 28k, an interstage coupling electrode 28f formed so as not to contact another conductor, and an input / output coupling electrode formed so as not to contact another conductor similarly to the electrode 28f. 28 g are provided. This is a difference from the first embodiment. That is, in (Example 1), the electrode for inter-stage coupling and the electrode for input / output coupling are respectively formed on different surfaces of the outer surface of the dielectric resonator, but in (Example 2), A cutout 28k was provided on each of the outer surfaces 28h, and electrodes 28f and 28g were formed in the cutout 28k, respectively.

The dielectric resonator 29 has substantially the same configuration as the dielectric resonator 28. That is, the dielectric substrate 29a,
It comprises a through hole 29b, an outer conductor 29c, an inner conductor 29d, a connecting conductor 29e, an electrode 29f for interstage coupling, an electrode 29g for input / output coupling, an outer surface 29h, an open end 29j, and a cutout 29k. Dielectric resonator 28 and dielectric resonator 29
The portions corresponding to the alphabets (for example, the dielectric substrate 28a and the dielectric substrate 29a) have substantially the same configuration. The reason why the dielectric resonators are described as having substantially the same configuration is that the dielectric resonator 28 and the dielectric resonator 29 have a mirror-symmetric relationship with each other, as can be seen from FIG. Therefore, care must be taken in the formation positions of the electrodes 28f and 28g and the formation positions of the electrodes 29f and 29g.

The dielectric resonator 28 and the dielectric resonator 29 are arranged such that the outer surfaces 28h and 29h do not face the outer surface of the other dielectric resonator, respectively, and the outer surfaces 28h and 29h.
Are joined by solder or the like so as to face the same direction. The electrode 28f and the electrode 29f are electrically connected to each other at the terminal 30. At this time, the terminal 30 is made of silver or copper,
The terminal 3 is made of a conductive material such as aluminum.
0 and the electrodes 28f and 29f are joined to each other by a conductive joining material such as solder. A terminal 31 is connected to the electrode 28g, and a terminal 32 is connected to the electrode 29g using a conductive bonding material such as solder. At this time, the terminals 31, 32 are each made of a conductive material such as copper or aluminum.

The outer conductors 28c, 29c and the inner conductor 28
d, 29d, connecting conductors 28e, 29e, electrodes 28f, 2
9f and the electrodes 28g and 29g (hereinafter, these films are collectively referred to as conductive films) are each formed of a thin film made of a conductive material such as copper or silver, and formed to have a thickness of about 5 μm. Is done. In this embodiment, the conductor film is composed of one layer, but may be composed of two or more layers. Further, the film thickness is 5
The thickness is about μm, but the film thickness must be appropriately determined depending on the conditions of use of the filter and the like.

In the second embodiment, the electrodes 28g, 29
Although the shapes of g and the electrodes 28f and 29f are square, they may be circular, elliptical, polygonal, or any other shape.

As described above, the dielectric filter of this embodiment has a very simple structure and can be miniaturized. Specifically, the central conductor and the dielectric substrate are not required in this embodiment, and the configuration is simplified, and as a result, the size can be reduced by about 50%.

FIG. 14 is a perspective view showing a state in which the dielectric filter according to the second embodiment of the present invention is mounted on a substrate. In FIG. 14, reference numeral 33 denotes a printed circuit board made of an insulating material such as glass or epoxy resin, reference numerals 34 and 35 denote input / output lines formed on the printed circuit board 33, respectively.
Is a ground line similarly formed on the printed circuit board 33. The terminal 31 of the dielectric resonator 28 is bonded to the input / output line 34 with a conductive bonding material such as solder.
5, the terminal 32 of the dielectric resonator 29 is joined with a conductive joining material such as solder. Further, the outer conductors 28c and 29c of the dielectric resonators 28 and 29 are joined to the ground line 36 with a conductive joining material such as solder. The input / output lines 34 and 35 and the ground line 36 are coated with a conductive paste such as Ag paste on the printed circuit board 33 in a predetermined shape.
Each is formed by baking. In this embodiment, since the terminal 30 is used for joining the electrode 28f and the electrode 29f, the electrical connection between the input / output lines 34 and 35 and the dielectric filter is made via the terminals 31 and 32. The electrical connection between the electrode 28f and the electrode 29f is performed by a bonding electrode provided on the printed circuit board 33, so that the terminal 30 can be omitted, and the terminals 31, 32 can be omitted accordingly. That is, to be more specific, a bonding electrode (not shown) is formed between the input / output lines 34 and 35 using a conductive material, and the dielectric resonator 2 bonded to each other is formed.
8 and 29 (in a state where the terminal 30 and the terminals 31 and 32 are not joined), the electrodes 28f and 29f are both in contact with the joining electrodes, and the input / output terminals 28g and 29g are connected to the input / output line 3
4 and 35 respectively, and further, the outer conductors 28c,
29c is brought into contact with the ground conductor 36. Then, they are joined to each other by a conductive joining material such as cream solder.
Therefore, by providing the terminal 30, the electrodes 28g, 2
Since there is no gap between the 9g and the printed circuit board 33, there is no need to receive the terminals 31 and 32 separately.

Further, a method of manufacturing the dielectric filter having the above-described structure can be manufactured by the same manufacturing method as that of the first embodiment, and thus the description thereof is omitted.

Next, an application example of (Embodiment 2) will be described. FIGS. 15 and 16 are a perspective view and an exploded perspective view showing a dielectric filter in an application example of the second embodiment of the present invention.

FIGS. 15 and 16 differ from the dielectric filters shown in FIGS. 12 and 13 in the shape of the through holes.
The through holes have the same diameter from the open end to the opposite side from the open end in the dielectric filter shown in FIGS. 12 and 13. In this embodiment, however, the through holes have different shapes and have a stepped portion in the middle. ing. That is, a through hole is formed in the dielectric filter 28 by a hole 28m having a square cross section and a hole 28n having a circular cross section connected to the hole 28m in the dielectric substrate 28a.
An inner conductor 28q is formed on the inner surface forming the through hole. Similarly, a through hole is formed in the dielectric filter 29 by a hole 29m having a rectangular cross section and a hole 29n connected to the hole 29m, and an inner conductor 29q is formed on the inner side surface forming the through hole. I have. In this way, the step is provided in the through hole, and the holes 28m and 29m on the open end side are each formed in a square shape and have a diameter larger than the holes 28n and 29n, so that the gap between the electrode 28g and the inner conductor 28q and the electrode 29g and the inner Since the input / output coupling capacitance between the conductors 29q can be increased, and the interstage coupling capacitance between the electrode 28f and the inner conductor 28q and between the electrode 29f and the inner conductor 29q can be increased, a wideband filter is formed. Can do things.

The other structure is the same as that shown in FIGS. (Embodiment 3) FIGS. 17 and 18 show a third embodiment of the present invention.
It is the perspective view and the exploded perspective view which show the dielectric filter in the Example of FIG. 17 and 18, reference numerals 37 and 38 denote dielectric resonators, respectively. Hereinafter, the structure of the dielectric resonator will be described using the dielectric resonator 37. Ba
_{O-TiO 2 -Nd 2 O 3} , BaO-TiO 2, ZrO 2 -
A through hole 37b is formed in a dielectric substrate 37a made of a dielectric material such as SnO ₂ —TiO ₂ or BaO—Sm ₂ O ₃ —TiO _2.
Is provided. At this time, the outer shape of the dielectric substrate 37a is rectangular, and the through-hole 37b is formed in a cylindrical cross section. An outer conductor 37c is provided on the outer surface of the dielectric substrate 37a, and an inner conductor 37d is provided on the inner surface forming the through hole 37b.
Is provided. The outer conductor 37c and the inner conductor 37d are connected by a connecting conductor 37e provided on one end surface. Notches 37p and 37k are formed on the open ends 37j of the outer surfaces 37i and 37h of the four outer surfaces of the dielectric substrate 37a so that the dielectric substrate 37a is exposed.
Are provided respectively. Further, an electrode 37f for inter-stage coupling formed so as not to contact other conductors is provided in a notch 37k provided in the outer surface 37h, and a notch 37p provided in the outer surface 37i is provided. Is provided with an input / output coupling electrode (not shown) similarly formed so as not to contact other conductors. Notch 37
p extends to the adjacent outer surface (the surface facing the printed circuit board to be mounted). Also, an L-shaped terminal 39 may be connected to the input / output coupling electrode. That is, according to the state of the printed circuit board on which the dielectric filter is mounted,
A terminal 39 or the like is joined to the input / output coupling electrode, and the terminal 39 and a conductive film (input / output line or the like) on the printed board are joined to each other by soldering or the like, or a terminal is provided on the input / output coupling electrode. Instead, the conductor film on the printed circuit board and the electrode for input / output coupling are directly joined by solder or the like. In the latter case, the notch 37p extends to the surface facing the printed circuit board to be mounted, so that the solder or the like that electrically connects the conductive film and the electrode for input / output coupling does not contact the outer conductor 37c. It has become.

The dielectric resonator 38 has substantially the same configuration as the dielectric resonator 37. That is, the dielectric substrate 38a,
The through-hole 38b, the outer conductor 38c, the inner conductor 38d, the connecting conductor 38e, the interstage coupling electrode 38f, and the input / output coupling electrode 38g (the input / output coupling electrode of the dielectric resonator 37 is the same as this electrode). ), An outer surface 38h, an outer surface 38i, an open end 38j, and notches 38k and 38p.
The portions of the dielectric resonator 37 and the dielectric resonator 38 corresponding to the alphabets (for example, the dielectric base 37a and the dielectric base 38a) have substantially the same configuration. The reason why the dielectric resonators 37 and 38 are described as having substantially the same configuration is that the dielectric resonator 37 and the dielectric resonator 38 are mirror-symmetrical to each other, as can be seen from FIG. Therefore, care must be taken in the formation positions of the electrodes 37f and 37g and the formation positions of the electrodes 38f and 38g. The electrode 38 g has a dielectric resonator 37.
Similarly to the above, the terminal 39 may be joined in the state of the printed circuit board to be mounted.

When the dielectric resonator 37 and the dielectric resonator 38 are joined to each other with cream solder or the like in such a manner that the electrodes 37f and 38f face each other, the electrodes 37g and 38g face the sides of the resonator, respectively. It has become. This is because these dielectric resonators have a mirror-symmetric relationship with each other as described above.

The outer conductors 37c, 38c and the inner conductor 37
d, 38d, connecting conductors 37e, 38e, electrodes 37f, 3
8f and the electrodes 37g and 38g (hereinafter, these films are collectively referred to as conductor films) are each formed of a thin film made of a conductive material such as copper or silver, and formed to have a thickness of about 5 μm. Is done. In this embodiment, the conductor film is composed of one layer, but may be composed of two or more layers. Further, the film thickness is 5
The thickness is about μm, but the film thickness must be appropriately determined depending on the conditions of use of the filter and the like.

In the third embodiment, the electrodes 37g, 38
Although the shapes of g and the electrodes 37f and 38f are square, they may be circular, elliptical, polygonal, or any other shape.

As described above, the dielectric filter of this embodiment has a very simple structure and can be miniaturized. Specifically, the central conductor and the dielectric substrate are not required in this embodiment, and the configuration is simplified, and as a result, the size can be reduced by about 50%.

FIGS. 19 and 20 are perspective views showing a state in which the dielectric filter according to the third embodiment of the present invention is mounted on a substrate. In FIG. 19, reference numeral 40 denotes a printed circuit board made of an insulating material such as glass epoxy resin;
Reference numeral 42 denotes an input / output line formed on the printed board 40, and reference numerals 43 and 44 denote ground lines formed on the printed board 40 so as to sandwich the input / output lines 41 and 42, respectively. A terminal 39 joined to an input / output coupling electrode 37g of the dielectric resonator 37 is joined to the input / output line 41 with a conductive joining material such as solder, and a dielectric resonator 38 is attached to the input / output line 42. Terminal 3 connected to the electrode 38g of
9 is joined with a conductive joining material such as solder. Further, dielectric resonators 37 and 38 are provided on the ground lines 43 and 44, respectively.
The respective outer conductors 37c, 38c are joined by a conductive joining material such as solder. The input / output lines 41 and 42 and the ground lines 43 and 44 are formed by applying a conductive paste such as an Ag paste on the printed circuit board 40 in a predetermined shape and baking the paste.

Further, as shown in FIG. 20, as a method of mounting a dielectric filter on a printed circuit board 40 without using the terminal 39, an electrode 3 for input / output coupling of a dielectric resonator 37 is used.
7 g and the electrode 38 g of the dielectric resonator 38 may be directly bonded to the input / output lines 41 and 42 by a conductive bonding material 45 such as solder. At this time, the conductive bonding material 45 is prevented from contacting the outer conductor 38g (the outer conductor 37g in the dielectric resonator 37).

The method of manufacturing the dielectric filter having the above-described structure is omitted here because it can be manufactured by the same manufacturing method as in the first embodiment.

Further, the out-of-band attenuation at each frequency of (Example 1) and (Example 3) was compared. Figure 2 shows the result.
It is shown in FIG. In FIG. 21, A is a line indicating the attenuation characteristic of (Example 3), and B is a line indicating the attenuation characteristic of (Example 1). As can be seen from FIG. 21, in the third embodiment, the out-of-band attenuation can be improved.

Incidentally, as in (Example 1) and (Example 2),
Also in this embodiment, the input / output coupling capacitance can be increased by forming the through holes provided in the dielectric substrates 37a and 38a to have a stepped shape as shown in FIG.
In addition, since the interstage coupling capacitance can be increased, a wideband filter can be configured.

Other structures are the same as those shown in FIGS. (Embodiment 4) FIGS. 22 and 23 show a fourth embodiment of the present invention.
It is the perspective view and the exploded perspective view which show the dielectric filter in the Example of FIG. 22 and 23, reference numerals 46 and 47 denote dielectric resonators having the same shape. Hereinafter, the structure of the dielectric resonator will be described using the dielectric resonator 46. _{BaO-TiO 2 -Nd 2 O 3} , BaO-TiO 2, Z
rO ₂ —SnO ₂ —TiO ₂ , BaO—Sm ₂ O ₃ —TiO ₂
A through hole 46b is provided in a dielectric substrate 46a made of a dielectric material such as. At this time, the outer shape of the dielectric substrate 46a is square, and the through-hole 46b is formed in a cylindrical cross section. An outer conductor 46c is provided on an outer surface of the dielectric base 46a, and an inner conductor 46d is provided on an inner surface forming the through hole 46b. Outer conductor 46c and inner conductor 46d
Are connected by a connecting conductor 46e provided on one end surface. Notches 46 are formed on the open ends 46j of the outer surfaces 46i and 46h of the four outer surfaces of the dielectric substrate 46a so that the dielectric substrate 46a is exposed.
p and 46k are provided respectively. Further outer surface 4
An electrode 46f for inter-step coupling formed so as not to contact other conductors is provided in a notch 46k provided in 6h, and a notch 46p provided in an outer surface 46i is similarly provided. Is provided with an input / output coupling electrode (not shown) formed so as not to contact other conductors. The notch 46p extends to the adjacent outer surface (the surface facing the printed circuit board to be mounted). Also, an L-shaped terminal may be connected to the input / output coupling electrode. That is, according to the state of the printed board on which the dielectric filter is mounted, a terminal or the like is bonded to the input / output coupling electrode, and the terminal and the conductor film (input / output line or the like) on the printed board are connected to each other by soldering or the like. The conductor film on the printed circuit board and the electrode for input / output coupling are directly joined by soldering or the like, without connecting the input / output coupling electrodes to the terminals. In the latter case, the notch 46p extends to the surface facing the printed circuit board to be mounted, so that the solder or the like that electrically connects the conductive film and the input / output coupling electrode does not contact the outer conductor 46c. It has become.

The dielectric resonator 47 has the same configuration as the dielectric resonator 46. That is, the dielectric substrate 47a, the through hole 47b, the outer conductor 47c, the inner conductor 47d, and the connecting conductor 47
e, an electrode for inter-stage coupling (same as the electrode 46f for inter-stage coupling of the dielectric resonator 46), and an electrode 47g for input / output coupling (the electrode for input / output coupling of the dielectric resonator 46 is also connected to this electrode). Similar configuration), outer surface 47h, outer surface 47i, open end 47
j, notches 47k and 47p. The dielectric resonator 46 and the dielectric resonator 47 correspond to portions corresponding to alphabets (for example, the dielectric base 46a and the dielectric base 47).
a) has the same configuration. Further, similarly to the dielectric resonator 46, a terminal may be joined to the electrode 47g depending on the state of the printed circuit board to be mounted.

When the dielectric resonator 46 and the dielectric resonator 47 are joined to each other with cream solder or the like while the electrodes 46f and 47f are opposed to each other, the dielectric resonator 46
The electrode for input / output coupling and the electrode 47g face the side surface of the resonator, and the open ends of the dielectric resonator 46 and the dielectric resonator 47 face the opposite directions. .

The outer conductors 46c, 47c, the inner conductor 46
d, 47d, connecting conductors 46e, 47e, electrode 46f (the same is applied to the interstage coupling electrode of the dielectric resonator 47), and the electrode 47
g (the same is also applied to the input / output coupling electrodes of the dielectric resonator 46) (hereinafter, these films are collectively referred to as conductor films). Each of them is formed of a thin film made of a conductive material such as copper or silver. The film is formed to have a thickness of about 5 μm. In this embodiment, the conductor film is composed of one layer, but may be composed of two or more layers. Further, the film thickness was set to about 5 μm, but the film thickness must be appropriately determined depending on the conditions of use of the filter and the like.

Further, in (Embodiment 3), the electrode 47g (the same electrode for input / output coupling of the dielectric resonator 46) and the electrode 4g are used.
Although the shape of 6f (same for the electrode for inter-stage coupling of the dielectric resonator 47) is square, it may be any shape such as a circle, an ellipse, or a polygon.

As described above, the dielectric filter of this embodiment has a very simple structure and can be miniaturized. Specifically, the central conductor and the dielectric substrate are not required in this embodiment, and the configuration is simplified, and as a result, the size can be reduced by about 50%.

Incidentally, similarly to (Example 1) and (Example 2),
Also in the present embodiment, by forming the through hole provided in the dielectric substrate into a shape having a step as shown in FIG.
Since the input / output coupling capacitance can be increased and the interstage coupling capacitance can be increased, a wideband filter can be configured.

The other constructions are the same as those shown in FIGS. (Example 1) to (Example 4)
Although the dielectric filter described above has been described using a configuration using two dielectric resonators, the same effect as described above can be obtained even when two or more dielectric resonators are used as shown in FIGS. 24, 25 and 26, for example. Can be obtained.

FIG. 24 is a perspective view showing a state when the dielectric filter of (Example 1) is constituted by using three dielectric resonators. In FIG. 24, reference numerals 11 and 12 have the same configuration as the dielectric resonator shown in (Example 1). Reference numeral 48 denotes a dielectric resonator provided between the dielectric resonator 11 and the dielectric resonator 12. The dielectric resonator 48 is provided with interstage coupling electrodes 48a and 48b on different outer surfaces. And no electrode for input / output coupling is provided. An electrode 11f for inter-stage coupling of the dielectric resonator 11 is joined to the electrode 48a, and an electrode 12f for inter-stage coupling of the dielectric resonator 12 is joined to the electrode 48b. As described above, in a dielectric filter in which three or more dielectric resonators are arranged, a dielectric resonator (hereinafter, abbreviated as an end resonator) provided with an electrode for interstage coupling and an electrode for input / output coupling is provided at both ends. A plurality of dielectric resonators (hereinafter abbreviated as interstage resonators) provided with interstage coupling electrodes between the end resonators are arranged, and the interstage coupling electrodes are joined to each other. In addition, the plurality of interstage resonators are joined, and the end resonator and the interstage resonator are joined with electrodes for interstage coupling. With such a configuration, the dielectric filter shown in (Embodiment 1) can use three or more dielectric resonators. FIG. 25 is a perspective view showing a state when the dielectric filter of (Example 2) is configured using three dielectric resonators. 25 in FIG.
8, 29 have the same configuration as the dielectric resonator shown in (Embodiment 2). Reference numeral 49 denotes a dielectric resonator provided between the dielectric resonator 28 and the dielectric resonator 29. The dielectric resonator 49 is provided with electrodes 49a and 49b for interstage coupling on the same outer surface. And no electrode for input / output coupling is provided. The electrode 49a is connected to an electrode 28f for interstage coupling of the dielectric resonator 28 via a terminal 50, and the electrode 4a
An electrode 29f for interstage coupling of the dielectric resonator 29 is joined to 9b via a terminal 50. As described above, in a dielectric filter in which three or more dielectric resonators are arranged, a dielectric resonator (hereinafter, abbreviated as an end resonator) provided with an electrode for interstage coupling and an electrode for input / output coupling is provided at both ends. A plurality of dielectric resonators (hereinafter abbreviated as interstage resonators) provided with interstage coupling electrodes between the end resonators are provided, and the interstage coupling electrodes are connected by terminals. A plurality of interstage resonators are joined to each other, and an interstage coupling electrode is joined between the end resonator and the interstage resonator by a terminal. With such a configuration, the dielectric filter shown in (Embodiment 2) can use three or more dielectric resonators.

FIG. 26 is a perspective view showing a state in which the dielectric filter of (Embodiment 3) is configured by using three dielectric resonators. 26, reference numerals 37 and 38 have the same configuration as the dielectric resonator shown in (Embodiment 3). Reference numeral 51 denotes a dielectric resonator provided between the dielectric resonator 37 and the dielectric resonator 38. The dielectric resonator 51 is provided with interstage coupling electrodes 51a and 51b on different outer surfaces. And no electrode for input / output coupling is provided. An electrode 37f for inter-stage coupling of the dielectric resonator 37 is joined to the electrode 51a, and an electrode 38f for inter-stage coupling of the dielectric resonator 38 is joined to the electrode 51b. As described above, in a dielectric filter in which three or more dielectric resonators are arranged, a dielectric resonator (hereinafter, abbreviated as an end resonator) provided with an electrode for interstage coupling and an electrode for input / output coupling is provided at both ends. A plurality of dielectric resonators (hereinafter abbreviated as interstage resonators) provided with interstage coupling electrodes between the end resonators are arranged, and the interstage coupling electrodes are joined to each other. In addition, the plurality of interstage resonators are joined, and the end resonator and the interstage resonator are joined with electrodes for interstage coupling. With such a configuration, the dielectric filter shown in (Embodiment 3) can use three or more dielectric resonators.

Similarly, in (Example 4), when three or more dielectric resonators are used, a plurality of interstage resonators are joined as described above, and an end resonator is formed at both ends. Can do things.

[0056]

According to the first aspect of the present invention, an inner conductor, an outer conductor, and a connecting conductor are provided on the inner side surface, the outer side surface, and one end surface of a prismatic dielectric substrate having a stepped through hole, respectively. An open end is provided on the other end surface, and a notch is provided continuously on the first and second outer surfaces of the dielectric substrate, whereby the inter-stage coupling electrode and the contact which are not in contact with the outer conductor are provided.
A pair of dielectric resonators having a coupling electrode, by electrically connecting the respective interstage coupling electrode of the pair of derivative <br/> collector resonators, and coupling the substrate and the center conductor Since the length of the dielectric filter can be shortened and the length of the dielectric filter can be shortened, the number of parts and the number of assembling steps can be reduced, and the size and productivity of the apparatus can be reduced. In addition, since the inter-stage coupling electrode is not surrounded on all sides by the outer conductor, the capacitance between the outer conductor and the outer conductor and the inter-stage coupling electrode that hinder broadband filter characteristics can be reduced. Can be reduced.
In addition, an electrode for interstage coupling and an electrode for connection are provided in one notch.
The notch can be easily formed.
In addition, man-hours are reduced and productivity is improved. According to a second aspect of the present invention, in the first aspect, a connection is made with the interstage coupling electrode.
Electrodes on the same outer surface of the dielectric substrate
The connection electrode is connected to the dielectric filter
Can be placed on the joint surface with the circuit board, etc.
The mounting area can be made very small, and the mounted board
And devices can be miniaturized . In the invention according to claim 3, the dielectric substrate is formed in a quadrangular prism shape, and
Notches and other cuts on one side and the opposite side
Notches are provided, and between the notches and other notches,
Provide the coupling electrode and connection electrode and other notches
Is provided over two outer surfaces so that the connection electrode
Can be placed on the side of the dielectric filter
Therefore, the degree of freedom in mounting is increased. In addition, for interstage coupling
Since the electrode and the connecting electrode can be formed separately,
Forming each electrode rather than forming each electrode in close proximity
Is easier, productivity is improved, and dielectric resonators are
The work can also be easily performed when joining them together.
Also, the other notch provided with the connection electrode is provided on one side and the other side.
The outer conductor provided on the other side between
On the connection electrode and the circuit board, etc.
When electrically connecting to the specified electrode, solder
The connection between the outer conductor and the connection electrode can be prevented.
Performance can be prevented, and workability is significantly improved.
The performance is improved . In the invention according to claim 4, claims 1 to 3 are provided.
The use of a dielectric substrate with a roughened surface
Therefore, the interstage coupling electrode with a relatively small bonding area and the dielectric
Since the bonding strength of the body substrate can be increased,
Sufficient joint strength is obtained even when the formation area is very small
And the size of the filter can be reduced . According to a fifth aspect of the present invention, in the fourth aspect, the surface of the dielectric substrate is provided.
By setting the surface roughness to 5 to 9 μm, the dielectric substrate
By setting the surface roughness to 5 μm or more, the dielectric substrate
And the bonding strength of each conductive film can be improved
By setting the thickness to 9 μm or less, the film characteristics of each conductive film
Can prevent the deterioration of the connection area of the electrode for interstage coupling.
Sufficient bonding strength and prevent deterioration of film properties even when smaller
The size of the filter can be reduced . In the invention according to claim 6, according to claim 4, the surface of the dielectric substrate is etched.
The surface treatment of the electric body substrate
Since it is possible to remove the adhering alterations,
The deterioration of the Q value of the filter can be prevented . In the invention according to claim 7, according to claim 2 or 3 , the step is formed in the through-hole of the dielectric substrate.
The difference allows the length of the dielectric resonator to be shortened.
The size of the filter can be reduced.
I can . In the invention according to claim 8, in claim 1 to 3 , the conductive film on the circuit board and the bonding electrode are directly bonded.
The electrical connection between the connection electrode and the circuit board.
Terminals are unnecessary, and the number of parts can be reduced.
It is very advantageous in terms of productivity and cost . According to the ninth aspect, in the first to third aspects, the dielectric substrate
Each conductor and electrode provided on the body have a multilayer structure
Can expand the versatility of each conductor and electrode.
And the film design becomes easier . In the invention according to claim 10,
A first dielectric resonator having a pair of interstage coupling electrodes;
A pair of second pairs according to any one of claims 1 to 3.
E Bei dielectric resonators, so as to sandwich the first dielectric resonator
A second dielectric resonator is arranged, and one of the first dielectric resonators is arranged.
A second dielectric resonator stage is provided for each pair of interstage coupling electrodes.
The amount of attenuation can be reduced by electrically connecting the coupling electrodes
Filter with excellent characteristics.
Can be provided .

[Brief description of the drawings]

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

FIG. 2 is an exploded perspective view showing a dielectric filter according to the first embodiment of the present invention.

FIG. 3 is a circuit diagram showing an equivalent circuit of the dielectric filter according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing a state in which the dielectric filter according to the first embodiment of the present invention is mounted on a substrate.

FIG. 5 is a characteristic diagram showing attenuation characteristics of the first embodiment and a conventional example.

FIG. 6 is a perspective view showing a method of manufacturing the dielectric resonator according to the first embodiment of the present invention.

FIG. 7 is a perspective view showing a method for manufacturing the dielectric resonator according to the first embodiment of the present invention.

FIG. 8 is a perspective view showing a method for manufacturing the dielectric resonator according to the first embodiment of the present invention.

FIG. 9 is a perspective view showing a method for manufacturing the dielectric resonator according to the first embodiment of the present invention.

FIG. 10 is a perspective view showing a dielectric filter in an application example of the first embodiment of the present invention.

FIG. 11 is an exploded perspective view showing a dielectric filter in an application example of the first embodiment of the present invention.

FIG. 12 is a perspective view showing a dielectric filter according to a second embodiment of the present invention.

FIG. 13 is an exploded perspective view showing a dielectric filter according to a second embodiment of the present invention.

FIG. 14 is a perspective view showing a state in which a dielectric filter according to a second embodiment of the present invention is mounted on a substrate.

FIG. 15 is a perspective view showing a dielectric filter in an application example of the second embodiment of the present invention.

FIG. 16 is an exploded perspective view showing a dielectric filter according to an application example of the second embodiment of the present invention.

FIG. 17 is a perspective view showing a dielectric filter according to a third embodiment of the present invention.

FIG. 18 is an exploded perspective view showing a dielectric filter according to a third embodiment of the present invention.

FIG. 19 is a perspective view showing a state in which a dielectric filter according to a third embodiment of the present invention is mounted on a substrate.

FIG. 20 is a perspective view showing a state in which a dielectric filter according to a third embodiment of the present invention is mounted on a substrate.

FIG. 21 is a characteristic diagram comparing the out-of-band attenuation at each frequency of the dielectric filters of (Example 1) and (Example 3).

FIG. 22 is a perspective view showing a dielectric filter according to a fourth embodiment of the present invention.

FIG. 23 is an exploded perspective view showing a dielectric filter according to a fourth embodiment of the present invention.

FIG. 24 is a perspective view showing a state when the dielectric filter of (Example 1) is configured using three dielectric resonators.

FIG. 25 is a perspective view showing a state when the dielectric filter of (Example 2) is configured by using three dielectric resonators.

FIG. 26 is a perspective view showing a state when the dielectric filter of (Example 3) is configured by using three dielectric resonators.

FIG. 27 is a perspective view showing a conventional dielectric filter.

28A is a front view of a coupling substrate of a conventional dielectric filter, and FIG. 28B is a rear view of a coupling substrate of a conventional dielectric filter.

[Explanation of symbols]

 11, 12 Dielectric resonator 11a, 12a Dielectric substrate 11b, 12b Through-hole 11c, 12c Outer conductor 11d, 12d Inner conductor 11e, 12e Connecting conductor 11f, 12f Electrode 11g, 12g Electrode 11k, 12k Notch

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01P 5/08 H01P 5/08 H 7/04 7/04 (56) References JP-A-6-112704 (JP, A) JP-A-4-200102 (JP, A) JP-A-4-150101 (JP, A) JP-A-3-108901 (JP, A) JP-A-6-13802 (JP, A) JP-A-3-273701 ( JP, A) Hikaru 3-86605 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01P 1/20-1/219 H01P 7/00-7/10 H01P 5 / 08

Claims (10)

(57) [Claims] 1. A prismatic shape having a cylindrical shape and a step in a through hole.
A dielectric substrate, an outer conductor provided on an outer surface of the dielectric substrate, an inner conductor provided on an inner surface of the dielectric substrate, and an outer conductor provided on one end surface of the dielectric substrate. A connection conductor connecting the conductor and the inner conductor, an open end provided on the other end surface of the dielectric base,
A first outer surface and a second outer surface adjacent to the first outer surface
The inter-stage coupling electrode and the connection electrode provided in a non-contact manner with the outer conductor by notches provided continuously on the respective surfaces.
And a pole, the cut portion is the a pair of dielectric resonators has been reached to the open end, electrically connected is a coupling electrode to each other between the pair of dielectric resonators each <br/> the stage Dielectric filter characterized by having been made . 2. An electrode in which the inter-stage coupling electrode and the bonding electrode are the same outside.
2. The dielectric filter according to claim 1, wherein the dielectric filter does not exist on the surface . 3. A dielectric substrate having a cylindrical and prismatic shape,
An outer conductor provided on an outer surface of a dielectric substrate;
An inner conductor provided on an inner side surface of the base;
Provided on one end face and connects the outer conductor and the inner conductor
And a connection conductor provided on the other end face of the dielectric substrate.
And a first open end on the first outer surface of the dielectric substrate.
The outer conductor is provided in a non-contact manner by providing
The inter-stage coupling electrode and the side opposite to the first outer surface.
By providing a second notch on the second outer surface of
Having a connection electrode provided in a non-contact manner with the outer conductor,
The first notch and the second notch are continuous.
When the first notch reaches the open end.
Both are between the open end and the interstage coupling electrode.
There is no conductor and the second cutout is outside the first
A third outer side adjacent to the side surface and the second outer side surface, respectively
A pair of dielectric resonators reaching the outer conductor on the side
The inter-stage coupling electrodes of the pair of dielectric resonators are connected to each other.
Dielectrics filter you characterized in that were electrically connected. 4. The dielectric filter according to claim 1, wherein the surface of the dielectric substrate is roughened . 5. The surface roughness of a dielectric substrate is set to 5 μm to 9 μm.
Dielectric filter according to claim 4, wherein the thing. 6. The dielectric filter according to claim 4 , wherein an etching process is performed on the dielectric substrate. 7. A through hole is provided in a dielectric substrate, and said through hole is formed in said through hole.
4. The method according to claim 2 , wherein a step is provided .
The dielectric filter as described in the above. 8. A device provided on a circuit board such as a printed board.
The dielectric filter according to any one of claims 1 to 3 , wherein the conductive film and the bonding electrode are directly bonded . 9. An outer conductor, an inner conductor, a short-circuit conductor, a connection electrode,
Dielectric filter as claimed in any one claims 1 to 3, wherein the respective coupling electrode interstage it has a multilayer structure. 10. A dielectric substrate, and an outer surface of the dielectric substrate
And an outer conductor provided on the inner surface of the dielectric substrate.
Provided on one end face of the dielectric substrate.
A connection conductor connecting the outer conductor and the inner conductor;
The outer conductor is not connected to the outer conductor by providing a cutout.
A first dielectric having a pair of interstage coupling electrodes provided in contact with each other
A body resonator and a second dielectric material according to any one of claims 1 to 3.
A pair of body resonators, and sandwich the first dielectric resonator.
The pair of second dielectric resonators is arranged as
Pair of interstage coupling electrodes provided in a dielectric resonator of the same
Between the respective stages of the pair of second dielectric resonators.
A dielectric filter comprising a coupling electrode joined thereto.