JP2000091811A - Filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain miniaturization, cost reduction, and high performance of a filter device. SOLUTION: Dielectric resonators 1, 2, and 3 are arranged in parallel, and capacitors C1, C2, and C3 and air-cored coils L1 and L2 are arranged on the same circuit board 4. The capacitors C1, C2, and C3 are directly soldered with terminal conductors 10 of the dielectric resonators 1, 2, and 3. The capacitors C1, C2, and C3 and the coils L1 and L2 are arranged on metallic boards 5a, 5b, and 5c. The coils L1 and L2 are arranged so as to be interposed among the capacitors C1, C2, and C3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter device for use in transmission, reception, transmission and reception of a communication device such as a portable telephone.

[0002]

2. Description of the Related Art A filter device such as a dielectric filter, a duplexer or a diplexer is constituted by a plurality of dielectric resonators and a plurality of capacitors, or a plurality of dielectric resonators, a plurality of capacitors and a plurality of inductance elements.

[0003]

However, in the conventional filter device, a special connecting member is used to connect the dielectric resonator and the capacitor, so that the size and cost of the filter device are reduced. In addition to being hindered, the connection circuit became longer, the loss and stray inductance increased, and the high-frequency characteristics deteriorated. In addition, it was troublesome to mount an air core coil as an inductor.

Accordingly, a first object of the present invention is to provide a filter device capable of easily and satisfactorily connecting a dielectric resonator and a capacitor. Also,
A second object of the present invention is to provide a filter device capable of easily connecting not only a capacitor but also a coil.

[0005]

The present invention for achieving the first object is a circuit board, a dielectric resonator disposed in parallel with a main surface of the circuit board, and a circuit board on the circuit board. And a capacitor connected to the dielectric resonator, wherein the dielectric resonator includes a dielectric substrate, an inner conductor, an outer conductor, and a terminal conductor, and the dielectric substrate is A first end face opposed to the second end face, a side face between the first end face and the second end face, and a through-hole extending from the first end face to the second end face; The outer conductor is disposed on the side surface,
The terminal conductor is disposed on the first end face and connected to the inner conductor, and the capacitor includes a dielectric substrate and a pair of capacitor electrodes formed on one main surface and the other main surface of the dielectric substrate. Wherein one of the capacitor electrodes of the capacitor pair is directly connected to the terminal conductor of the dielectric resonator. According to another aspect of the present invention, there is provided a circuit board, a plurality of dielectric resonators arranged in parallel with each other on the circuit board, and a plurality of dielectric resonators arranged on the circuit board. A filter device comprising: a plurality of capacitors respectively connected to a body resonator; and at least one coil disposed on the circuit board and connected between the plurality of capacitors, wherein the plurality of dielectric resonators Each include a dielectric substrate, an inner conductor, an outer conductor, and a terminal conductor, wherein the dielectric substrate has first and second end faces facing each other, a side face between the first and second end faces, And a through hole extending from the end surface of the first conductor to the second end surface, the inner conductor is disposed in the through hole, the outer conductor is disposed on the side surface, and the terminal conductor is disposed on the first end surface. And connected to the inner conductor Each of the plurality of capacitors includes a dielectric substrate and a pair of capacitor electrodes formed on one main surface and the other main surface of the dielectric substrate, and the dielectric substrate of each of the plurality of capacitors is The main surface is arranged so as to face the main surface of the circuit board,
The capacitor electrode farthest from the circuit board among the capacitor electrodes of each pair of the plurality of capacitors is connected to the terminal conductor of the dielectric resonator, and the plurality of capacitors are connected to the plurality of dielectric resonators. Similarly, the plurality of capacitors are connected to the respective connection conductor layers on the circuit board directly or via respective metal plates, and the plurality of capacitors are connected to the respective connection conductor layers or the metal corresponding to the plurality of capacitors. Each of the plates is connected to the capacitor electrode closer to the circuit board among the capacitor electrodes of the capacitor pair, and the connecting conductor layer or the metal plate projects from the dielectric substrate of the capacitor in plan view. A portion, wherein the protruding portion is provided so as to protrude between the plurality of capacitors, and the end of the coil protrudes from the plurality of capacitors. Those related to the filter device which is arranged at a portion that. The dielectric substrate of the capacitor can be arranged perpendicular to the main surface of the circuit board. Further, as described in claim 4, a plurality of resonators can be formed using the same dielectric substrate. Further, a concave portion can be formed in the connection portion of the capacitor electrode as described in claim 5. Claim 6
As shown in the above, a member for closing the through hole of the resonator can be provided.

[0006]

According to the present invention, since the capacitor electrode conductor layer is directly connected to the dielectric resonator, the connection between the two can be easily achieved, and the cost can be reduced. it can. Further, the loss and the parasitic inductance of the connection portion can be reduced, and the characteristics can be improved. According to the second aspect of the present invention, the coil is arranged between two dielectric substrates adjacent to each other, and the end of the coil is connected to the protruding portion of the connection conductor layer or the metal plate. Mounting can be easily achieved. According to the fifth and sixth aspects of the present invention, it is possible to prevent the conductive bonding material such as solder from entering the through hole of the dielectric resonator and prevent the inner conductor from deteriorating.

[0007]

Embodiments and Examples Next, embodiments and examples of the present invention will be described with reference to FIGS.

[0008]

First Embodiment A filter device according to a first embodiment is shown in FIG.
EMI mode coaxial type first, second and third dielectric resonators 1, 2, 3 and capacitors C1, C2, C3, C
4, C5 and C6, and inductance coils L1 and L2. The coils L1 and L2 are connected in series between the first and second input / output terminals T1 and T2, and the dielectric resonator 1,
2 and 3 are connected between the signal transmission line and ground via capacitors C1, C2 and C3, and capacitors C4 and C5 are connected.
, C6 are connected between the signal transmission line and the ground. As shown in FIG. 2, the filter device having the equivalent circuit shown in FIG. 1 includes a circuit board 4 and spacer metal plates 5a, 5b, 5c.
It is configured with. Note that 5b may be a capacitor substrate.

Each of the dielectric resonators 1 to 3 in FIG. 2 has substantially the same configuration. Therefore, the details of the first dielectric resonator 1 will be described with reference to FIG. 4, and the description of the other dielectric resonators will be omitted. Further, other dielectric resonators are given the same reference numerals as in FIG. The dielectric resonator 1 includes a cylindrical ceramic dielectric substrate 6, an inner conductor 7, an outer conductor 8, a short-circuit conductor 9, and a terminal conductor 10. The dielectric substrate 6 has a through hole 13 extending from the first end face 11 to the second end face 12, and the inner conductor 7 is formed on a wall surface of the through hole 13. The outer conductor 8 is formed on the outer peripheral side surface 14 of the dielectric substrate 6.
The short-circuit conductor 9 is secondly connected to connect the inner conductor 7 and the outer conductor 8.
Is formed on the end face 12 of the hologram. The terminal conductor 10 is provided on the first end face 11 and is connected to the inner conductor 7. The inner conductor 7, the outer conductor 8, the short-circuit conductor 9, and the terminal conductor 10 are formed by applying a conductive paste and firing the paste. Note that electrical isolation between the outer conductor 8 and the terminal conductor 10 is achieved at the small-diameter portion 14 a on the first end face 11 side of the dielectric base 6.
The three dielectric resonators 1, 2, 3 are juxtaposed on the insulating circuit board 4, and the respective outer conductors 8 are fixed to the ground conductor layer 15 of the circuit board 4 with a conductive bonding material 16 such as solder. .

[0010] First, second and third capacitors C1, C
2 and C3 comprise a dielectric substrate 17 and first and second capacitor electrodes 18 and 19, respectively, as shown in FIGS. The first capacitor electrode 18 is provided on most of one main surface of the rectangular dielectric substrate 17, and the second capacitor electrode 19 has a portion facing the first capacitor electrode 18. Of the other main surface. Note that the first capacitor electrode 18 is slightly separated from the three peripheral edges of the rectangular dielectric substrate 17 and approaches the other peripheral edge on the dielectric resonators 1, 2, and 3 side. Having. Also, the second
The capacitor electrode 19 has a pattern slightly away from the peripheral edge of the lower surface of the dielectric substrate 17 on the side of the dielectric resonators 1, 2, and 3.

The capacitors C4, C5 and C6 are formed by using a dielectric circuit board 4. That is, the first, second, and third conductor layers 20, 21, and 22 are formed on one main surface of the circuit board 4 as shown in FIG. , The second and third conductor layers 20, 21, 2
The ground conductor layer 23 is formed so as to oppose the capacitor C2, thereby providing the capacitances of the capacitors C4, C5 and C6. The ground conductor layer 23 is provided on one main surface (upper surface) side of the circuit board 4 and the conductor layer 2 is formed on the same main surface.
0, 21, and 22 may be opposed to each other with a predetermined gap. Ground conductor layer 15 on the front side of circuit board 4
Extends to the back side of the circuit board 4 through the groove 15a, and has a function as the input / output terminals T1 and T2.
Reference numerals 0 and 22 also extend to the back surface side of the circuit board 4 via the grooves 20a and 22a.

First, second, and third rectangular metal plates 5a, 5b, and 5c are fixed on the conductor layers 20, 21, and 22 by solder 24 as a conductive bonding material. The metal plates 5a, 5b and 5c have portions 25 projecting between the capacitors C1, C2 and C3, respectively, as is apparent from FIGS. In addition, the metal plates 5a, 5
b and 5c are arranged so as to be separated from the terminal conductors 10 of the dielectric resonators 1, 2, and 3.

The lower electrodes 19 of the capacitors C1, C2 and C3 are connected to the metal plate 5 by solder 26 as a conductive bonding material.
a, 5b, and 5c. Capacitors C1, C
2, the C3 dielectric substrate 17 is disposed so as to press against the terminal conductors 10 of the dielectric resonators 1, 2, and 3, and the upper electrode 18 is connected to the terminal conductor 10 by solder 27 as a conductive bonding material. ing.

The air-core coils L1, L2 are connected to capacitors C1,
Metal plates 5a, 5b, 5 are disposed between C2 and C3.
c. That is, the length (width) of the coil L1 is determined by the dielectric substrate 17 of the first and second capacitors C1 and C2.
Of the coil L1
Are arranged so as to be sandwiched between them. Coil L1
Are arranged so as to extend in the same direction as the through-holes 13 of the dielectric resonators 1, 2, and 3, and project from the first and second metal plates 5a, 5b. Part 25
It is fixed thereon by solder 26 as a conductive bonding material. The length (width) of the coil L2 is determined so as to substantially match the mutual interval between the dielectric substrates 17 of the second and third capacitors C2 and C3, and the coil L2 is arranged so as to be sandwiched therebetween. ing. A pair of linearly extending terminals of the coil L2 are through holes 1 of the dielectric resonators 1, 2, and 3.
3 and are arranged to extend in the same direction as
Are fixed on the protruding portions 25 of the metal plates 5b and 5c with solder 26 as a conductive bonding material. The capacitor C1
, C2, C3 and the coils L1, L2 are connected to the metal plates 5a, 5a.
b, 5c, a solder layer is formed on the metal plates 5a, 5b, 5c, and the capacitors C1, C2, C
3 and the coils L1 and L2 are simultaneously arranged, and the solder layer is reflowed.

This embodiment has the following effects. (1) Capacitors C1, C2, C3 and coils L1, L
2 can be simultaneously arranged on the metal plates 5a, 5b, and 5c on the same plane and can be simultaneously fixed by solder reflow with a self-alignment action, so that assembly is facilitated and cost can be reduced. (2) One electrode 18 of capacitors C1, C2 and C3
Is directly connected to the terminal conductors 10 of the dielectric resonators 1, 2, and 3 with the solder 27, so that a special member for connection is not required, and the connection can be achieved simply and at low cost.
The stray inductance and loss at the connection are reduced,
The characteristics of the filter can be improved.

[0016]

Second Embodiment Next, a filter device according to a second embodiment will be described with reference to FIGS. However, FIGS.
In FIGS. 12 to 17, which will be described later, parts common to FIGS. 1 to 6 and parts common to each other are denoted by the same reference numerals and description thereof is omitted.

The filter device according to the second embodiment shown in FIGS. 7 to 11 differs from the circuit of FIG. 1 in that the capacitor C4 is omitted.
The first embodiment is that the capacitors C1, C2, C3 are arranged perpendicular to the main surface of the circuit board 4, the capacitors C5, C6 are blocked, and the connection of the coils L1, L2 is changed. In other respects, the configuration is almost the same as that of the first embodiment.

The plate-like first, second and third capacitors C 1, C 2, C 3 are arranged on a circuit board such that one of the electrodes 18 closes the through-hole 13 of the dielectric resonator 1, 2, 3. 4, and is directly connected to the terminal conductor 10 by a conductive bonding material 27 such as solder. The other electrode 19 of the first capacitor C1 is connected to the metal plate 5a by solder 26. The other electrodes 19 of the second and third capacitors C2 and C3 are connected to the conductor layers 42 and 43 on the dielectric substrate 41 of the capacitor block 40 by solder 26.

The capacitor block 40 includes the dielectric substrate 4
One has the above-mentioned conductor layers 42 and 43 on one main surface, and has a ground conductor layer 44 on the other main surface. Therefore, the opposition of the conductor layers 42 and 43 and the ground conductor layer 44 causes
Of the capacitors C5 and C6. The ground conductor layer 44 of the dielectric substrate 41 is connected to the ground conductor layer 15b of the circuit board 4 by solder 45 as a conductive bonding material.

One of the pair of terminals 28 of the air-core coil L1 is fixed to the metal plate 5a with a conductive bonding material (not shown), and the other is fixed to the conductor layer 42 with a conductive bonding material (not shown). ing. The ends 30 of the pair of air-core coils L2 are the conductor layers 42, 4
3 is fixed by a conductive bonding material (not shown). The conductor layer 43 is connected to the conductor layer 22 of the circuit board 4 by solder 45.

The filter device according to the second embodiment has the following effects. (1) Since the capacitors C1, C2, and C3 are arranged perpendicular to the circuit board 4 and the electrode 18 is directly connected to the terminal conductor 10, the connection portion between them is shortened, and the loss and stray inductance here are reduced. And the characteristics can be improved. Further, the size of the dielectric resonators 1, 2, and 3 of the filter device in the extending direction of the through holes 13 can be reduced. (2) Since the connecting members for the dielectric resonators 1, 2, and 3 are not required, the cost can be reduced accordingly. (3) Capacitors C1, C2, and C3 are coils L1, L
2, the effect of the electromagnetic field of the coils L1, L2 on the capacitors C1, C2, C3 can be reduced, and the characteristics can be stabilized. (4) The capacitor C1 is connected to the metal plate 5a and the dielectric resonator 1
And the capacitors C2 and C3 are sandwiched between the capacitor block 40 and the dielectric resonators 2 and 3, so that the capacitors C1, C2 and C3 are easily mounted.
In addition, the mounting accuracy is improved. (5) Capacitor C by capacitor block 40
5 and C6 are integrally formed, and the capacitors C5 and
Since the conductor layers 42 and 43 functioning as one electrode of C6 are used for the connection of the coils L1 and L2 and the connection of the capacitors C2 and C3, not only the miniaturization can be achieved, but also the connection of each part becomes easy.

[0022]

Third Embodiment A filter device according to a third embodiment shown in FIGS. 12 and 13 is a duplexer including a transmission filter 51 and a reception filter 52 as shown in FIG. The transmission filter 51 has the same circuit configuration as that of FIG. 7, and is connected between the transmission input terminal Tt and the antenna terminal Ta. The receiving filter 52 includes two dielectric resonators 53 and 54 and three capacitors C11, C12 and C13, and is connected between the antenna terminal Ta and the reception output terminal Tr.

FIG. 13 shows the geometric configuration of the duplexer of this embodiment. The transmission filter 51 on the left side has substantially the same configuration as that of FIG. Right receiving filter 5
The two dielectric resonators 53 and 54 are juxtaposed to the dielectric resonators 1, 2, and 3 of the transmission filter 51.

The receiving-side capacitor block 55 is configured by providing conductor layers 57 and 58 on one main surface of a dielectric substrate 56 and providing conductor layers 59 and 60 on the other main surface. A capacitor C11 is obtained by opposing the conductor layers 57 and 59, a capacitor C12 is obtained by opposing the conductor layers 57 and 58, and a capacitor C13 is obtained by opposing the conductor layers 58 and 60. The conductor layers 57 and 58 as capacitor electrodes are pressed against the terminal conductors 10 of the dielectric resonators 53 and 54 and are connected by a conductive bonding material 61 made of solder. The lower conductor layer 59 is connected to the antenna terminal Ta,
The conductor layer 60 is connected to the reception output terminal Tr.

The third embodiment has the same effects as the second embodiment, and also has a high-performance filter device for transmission and reception.
This has the effect that it can be made easily and at low cost.

[0026]

Fourth Embodiment A filter device according to a fourth embodiment shown in FIGS. 14 and 15 has through holes 13 in dielectric resonators 1, 2, and 3.
3 and 4 except for the closing member 70 shown in FIG.
The configuration is the same as that of the first embodiment shown in FIG.

The closing member 70 is a metal stud, and is formed so that the protruding portion is inserted into the through hole 13 and the flange portion is fixed to the terminal conductor 10. When the closing member 70 is provided,
Penetration of the conductive bonding material 27 such as solder into the through hole 13 is prevented, and deterioration of the inner conductor (for example, silver solder erosion) can be prevented. Note that the fourth embodiment also has the same effect as the first embodiment.

[0028]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) Electrodes 18 of capacitors C1, C2 and C3 in FIG.
As a modification of the above pattern, a concave portion 80 can be provided at the resonator connecting portion as shown in FIG. That is, a concave portion 80 having a width substantially equal to the diameter of the through holes 13 of the dielectric resonators 1, 2, and 3 is provided, and both sides of the concave portion 80 are connected to the terminal conductor 10 with a conductive bonding material such as solder. Can be fixed. This suppresses the intrusion of the conductive bonding material into the through-hole 13, and the same effect as in the fourth embodiment can be obtained. Note that the same components as the concave portions 80 can be provided in the conductor layers 57 and 88 in FIG. (2) The connection structure of the capacitors C1, C2, and C3 of the first, second, and fourth embodiments can be applied to a filter having no coil, such as the reception filter 52 of FIG. it can. (3) The number of dielectric resonators can be increased or decreased. For example, the present invention can be applied to a case where a trap circuit is formed by combining one dielectric resonator and one capacitor. (4) In each embodiment, instead of providing the first, second, and third dielectric resonators 1, 2, and 3 individually, a plurality of resonance resonators may be provided on one dielectric base 6 as shown in FIG. Through hole 1
3, an inner conductor 7 is provided in each through hole 13, an outer conductor 8 is provided on a side surface of the dielectric substrate 6, and a terminal conductor 10 is provided on one end surface.
, A short-circuit conductor 9 is provided on the other end face, and a dielectric filter (resonator block) having a structure in which a coupling hole 120 is provided between the resonance through holes 13 can be used. The overall configuration of a filter device using such a resonator block has a configuration in which the resonator blocks of FIG. 17 are arranged in the portions of the resonators 1, 2, and 3 of the first to fourth embodiments. (5) The short-circuit conductor 9 can be omitted to form a half-wavelength resonator. (6) The present invention can be applied to a diplexer used for a dual-band transceiver. (7) The conductor layers 20, 21, 22 can be formed sufficiently thick, and the metal plates 5a, 5b, 5c can be omitted. (8) The closing member 70 shown in FIG. 14 and FIG.
The second embodiment of FIG. 10, the third embodiment of FIG. 13, and FIG.
Can also be used for the modified example. (9) In FIGS. 7 and 12, the capacitor C4 of FIG.
Can be provided. (10) In the first embodiment shown in FIGS. 1 to 6, instead of using the dielectric of the substrate 4 for the capacitor C5,
A flat plate capacitor including a dielectric substrate and a pair of capacitor electrodes is prepared, and the flat plate capacitor is connected to a metal plate 5b.
, And the coils L1 and L2 are connected to the upper electrode of the plate-type capacitor, and the lower electrode is connected to the ground. In this case, the conductor layer 21 in FIG. 3 is a ground conductor layer.

[Brief description of the drawings]

FIG. 1 is an equivalent circuit diagram of a filter device according to a first embodiment.

FIG. 2 is a plan view of the filter device according to the first embodiment.

FIG. 3 is a front view of the filter device of FIG. 2;

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is an enlarged perspective view showing the capacitor of FIG. 2;

FIG. 6 is an enlarged perspective view showing the coil of FIG. 2;

FIG. 7 is an equivalent circuit diagram of the filter device according to the second embodiment.

FIG. 8 is a plan view of a filter device according to a second embodiment.

FIG. 9 is a front view of the filter device of FIG.

FIG. 10 is a sectional view taken along line BB of FIG. 9;

FIG. 11 is a plan view of the capacitor block of FIG.

FIG. 12 is an equivalent circuit diagram of a filter device according to a third embodiment.

FIG. 13 is a plan view of a filter device according to a third embodiment.

FIG. 14 is a front view of a filter device according to a fourth embodiment.

FIG. 15 is a sectional view taken along line CC of FIG. 14;

FIG. 16 is a plan view showing a part of a capacitor according to a modification.

FIG. 17 is a perspective view showing a dielectric filter according to a modification.

[Description of Signs] 1, 2, 3 Dielectric resonator 4 Circuit board 5a, 5b, 5c Metal plate C1, C2, C3 Capacitor L1, L2 Air core coil

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoto Kobayashi 6-16-20 Ueno, Taito-ku, Tokyo Inside Taiyo Denki Co., Ltd. (72) Toshio Shimizu 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Denki Co., Ltd. (72) Inventor Makoto Inoue 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Denki Co., Ltd. F-term (reference) within Denki Corporation 5J006 HA03 HA14 HA25 HA34 JA01 KA02 LA13 LA25 LA27 NA04 NB07 NB08 NC01 NC02 NF01

Claims (6)

[Claims] 1. A circuit board, comprising: a dielectric resonator disposed parallel to a main surface of the circuit board; and a capacitor disposed on the circuit board and connected to the dielectric resonator. A filter device, wherein the dielectric resonator includes a dielectric substrate, an inner conductor, an outer conductor, and a terminal conductor, wherein the dielectric substrate has first and second end faces facing each other, and the first and second end faces. And a through hole extending from the first end surface to the second end surface, the inner conductor is arranged in the through hole, the outer conductor is arranged on the side surface, and the terminal conductor Is disposed on the first end face and connected to the inner conductor, the capacitor comprises a dielectric substrate and a pair of capacitor electrodes formed on one main surface and the other main surface of the dielectric substrate, One of the capacitor electrodes of the capacitor pair There filter apparatus characterized by being directly connected to the terminal conductor of the dielectric resonator. 2. A circuit board, a plurality of dielectric resonators arranged on the circuit board in parallel with each other, and a plurality of dielectric resonators arranged on the circuit board and connected to the plurality of dielectric resonators, respectively. A capacitor and at least one capacitor disposed on the circuit board and connected between the plurality of capacitors;
A filter device having two coils, wherein each of the plurality of dielectric resonators includes a dielectric substrate, an inner conductor, an outer conductor, and a terminal conductor, and the first and second dielectric substrates face each other. And a side surface between the first and second end surfaces and a through hole extending from the first end surface to the second end surface, wherein the inner conductor is disposed in the through hole, and the outer conductor is The terminal conductor is disposed on the side surface, the terminal conductor is disposed on the first end surface and connected to the inner conductor, and each of the plurality of capacitors includes a dielectric substrate, one main surface of the dielectric substrate, and the other. And a pair of capacitor electrodes formed on a main surface, wherein the dielectric substrate of each of the plurality of capacitors is disposed such that a main surface thereof is opposed to a main surface of the circuit board. Twin condensate Among the electrodes, a capacitor electrode remote from the circuit board is connected to the terminal conductor of the dielectric resonator, and the plurality of capacitors are juxtaposed to each other similarly to the plurality of dielectric resonators. Are connected directly or via respective metal plates to respective connection conductor layers on the circuit board, and each of the connection conductor layers or metal plates corresponding to the plurality of capacitors is a capacitor of the capacitor pair. The connection conductor layer or the metal plate is connected to a capacitor electrode closer to the circuit board among the electrodes, and the connection conductor layer or the metal plate has a portion projecting from a dielectric substrate of the capacitor as viewed in plan, and the projecting portion Is provided so as to protrude between the plurality of capacitors, and an end of the coil is disposed at the protruding portion. Filter device. 3. A circuit board, a plurality of dielectric resonators arranged on the circuit board in parallel with each other, and a plurality of dielectric resonators arranged on the circuit board and connected to the plurality of dielectric resonators, respectively. A capacitor and at least one capacitor disposed on the circuit board and connected between the plurality of capacitors;
A filter device having two coils, wherein each of the dielectric resonators includes a dielectric substrate, an inner conductor, an outer conductor, and a terminal conductor, and the dielectric substrate has first and second end faces facing each other. And a side surface between the first and second end surfaces and a through hole extending from the first end surface to the second end surface, wherein the inner conductor is disposed in the through hole, and the outer conductor is the side surface Wherein the terminal conductor is disposed on the first end face and connected to the inner conductor, and each of the plurality of capacitors includes a dielectric substrate and one main surface and the other main surface of the dielectric substrate. And a pair of capacitor electrodes formed on each of the plurality of capacitors, wherein the dielectric substrate of each of the plurality of capacitors has a main surface arranged perpendicular to a main surface of the circuit board, and each pair of the plurality of capacitors Of the capacitor electrode Write is the dielectric is directly connected to the terminal conductor of the resonator, the coil filter apparatus characterized by being connected between the other mutual electrode pairs of the plurality of capacitors. 4. A filter device comprising a circuit board, a resonator block including a plurality of resonators, and a capacitor, wherein the resonator block has first and second end faces facing each other and the first and second end faces. A dielectric substrate having a side face between the second end faces and a plurality of through holes formed from the first end face to the second end face, and a plurality of dielectric bases respectively arranged in the plurality of through holes Having an inner conductor, an outer conductor arranged on the side surface, and a plurality of terminal conductors arranged on the first end face and connected to the plurality of inner conductors, respectively. Having a dielectric substrate and a pair of capacitor electrodes disposed on the circuit board, one of the pair of capacitor electrodes being directly connected to the terminal conductor by a conductive bonding material. Filter apparatus. 5. The capacitor according to claim 1, wherein a concave portion made of a non-conductive region is formed at a tip of one capacitor electrode of the capacitor, and the concave portion corresponds to the through hole of the dielectric resonator. The filter device according to any one of claims 1 to 4. 6. The filter device according to claim 1, wherein a through hole of the dielectric resonator is closed by a metal closing member.