JPS63174401A - Dielectric filter device - Google Patents

Abstract

PURPOSE:To obtain a device possible to be used as a shared apparatus suitably and with superior mechanical strength and resulting low cost, by constituting plural filter parts in a single dielectric block. CONSTITUTION:A dielectric filter device 30 is constituted in such a way that a first filter part 41 consisting of a resonator constituted at through holes 32 and 33 on both sides of a coupling hole 37 is provided, and a second filter part 42 consisting of the resonator constituted at through holes 34 and 35 on both sides of a coupling hole 38 is provided in a single dielectric block 31. Also, a filter coupling hole 43 is formed between filter parts 41 and 42, and in the filter coupling hole 43, a connection terminal 44 capacitive coupled with adjacent inner conductors 33a and 34a is inserted with pressure. And the filter parts 41 and 42 are coupled with each other to the connection terminal 44. Therefore, it is not necessary to increase the number of the dielectric blocks even when it is utilized as the shared apparatus in which a large number of filters are combined.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dielectric filter device used as a duplexer such as a duplexer, for example.

[Prior Art] FIG. 2 is a block diagram showing an example of a duplexer that forms the background of the present invention. The duplexer 1 includes a first bandpass filter 2a with a center frequency f, and a second bandpass filter 2b with a center frequency f2. The input sides of both bandpass filters 2a, 2b are connected to a common terminal 4 via a connection point 3, respectively. On the other hand, each bandpass filter 2a.

The output sides of 2b are connected to output terminals 5a and 5b, respectively. If the frequency component of the high-frequency signal input from the common terminal 4 includes a signal with a frequency f, the signal is guided to one output terminal 5a via the first bandpass filter 2a. Similarly, if a signal with frequency f2 is included, this signal is led out to the other output terminal 5b via the second bandpass filter 2b.

FIG. 3 is a perspective view showing a conventional dielectric filter device used as the duplexer 1 described above. In this dielectric filter device @10, a separate dielectric block 11.
12, the first and second band pass filters 2a and 2b are constructed. That is, a plurality of through holes 11a to 11c and 12a to 12C are formed in parallel to each other in each dielectric block 11.12. Each through hole 11a to 110 and 12a to 12C
An inner conductor (not shown) is formed on the inner peripheral surface of each dielectric block 11.12, and an outer conductor that cooperates with the inner conductor to form a resonant unit is formed on the outer peripheral surface of each dielectric block 11.12. has been done. In each dielectric block 11.12, inner conductors formed on the inner peripheral surface of each through hole 118 to 110.12a to 12c are coupled to each other by a coupling hole 13.14 to form a filter. There is.

By the way, in the dielectric filter device 10, the structure corresponding to the connection point 3 in FIG. 2 is, as shown in FIG. .16 and a connecting piece 17 that connects the input/output pins 15 and 16. Input/output pin 1
5.16 each has a synthetic resin cylinder 20.21 fixed around a central conductor made of a metal material, and the central conductor is connected to a connecting piece 17 on the outside of a dielectric block 11.12.
The connection point 3 in FIG. 2 is configured by the connection.

Problems to be Solved by the Invention In the dielectric filter device 10 described above, the filter sections disposed on both sides of the connection point 3 in FIG. 2, that is, the filter sections disposed on both sides of the branch section, are separated. dielectric block 1
It is configured using 1.12. Therefore, both bandpass filters 2a.

2b (FIG. 2), a dielectric block 11, 12 must be provided for each filter, and an inner conductor and an outer conductor must be formed in each dielectric block. Therefore, the manufacturing process is complicated and the number of parts increases in proportion to the number of filters combined, making it difficult to reduce manufacturing costs. Furthermore, since a plurality of dielectric blocks 11 and 12 are combined, there is a problem in that even if they are integrated using a holding case 22 or the like, the mechanical strength is not very high.

Therefore, an object of the present invention is to provide a dielectric filter device that can be suitably used as a duplexer as described above, has excellent mechanical strength, and can be manufactured at low cost.

[Means for Solving the Problems] The dielectric filter device of the present invention utilizes a single dielectric block in which three or more through holes are formed in parallel to each other. An inner conductor is formed on the inner peripheral surface of each of the through holes, and an outer conductor is formed on the outer peripheral surface of the dielectric block. This outer conductor constitutes a resonant unit in cooperation with each inner conductor. Further, a filter section is constituted by a number of resonance units, and a plurality of filter sections are constituted within the dielectric block as a whole.

A filter coupling hole is formed between adjacent inner conductors between at least one set of adjacent filter sections among the plurality of filter sections, and further, a filter coupling hole is formed between adjacent inner conductors of at least one set of adjacent filter sections, and a A connecting terminal is provided which is capacitively coupled to the mating inner conductor.

[Operations and Effects of the Invention] In the present invention, a plurality of filter sections are configured within a single dielectric block. Therefore, there is no need to prepare a separate dielectric block for each filter section, and there is no need to separately form the inner conductor and outer conductor for each filter section. Therefore, even when used in a duplexer that combines a large number of filters, there is no need to increase the number of dielectric blocks, so it can be manufactured at low cost.

Furthermore, since a single dielectric block is used, a dielectric filter device with excellent mechanical strength can be obtained without preparing a special holding case or the like.

[Explanation of Examples] FIG. 1 is a sectional view of an embodiment of the present invention.

The dielectric filter device @30 of this embodiment is constructed using a single dielectric block 31.

A plurality of n through holes 32 to 35 are formed in the dielectric block 31 in parallel to each other. By applying a conductive material to the inner peripheral surface of each of the 14 through holes 32 to 35, inner conductors 328 to 35 are formed.
35a is formed.

On the other hand, an outer conductor 36 is formed on the outer peripheral surface of the dielectric block 31. This outer conductor 36 and inner conductor 32a.~3
5a constitutes a resonator, that is, a λ/4 type TEM coaxial resonator.

Further, a coupling hole 37 is formed between the through hole 32 and the through hole 33, and a coupling hole 38 is formed between the through hole 34 and the through hole 35, respectively. Each coupling hole 37, 38 is provided for coupling the resonators formed on both sides thereof. Therefore, in the dielectric filter device 30 of this embodiment, the first filter section 41 made of a resonator is configured in the through holes 32 and 33 on both sides of the coupling hole 37;
Second filter sections 42 made of resonators are provided in portions of the through holes 34 and 35 on both sides of the coupling hole 38. In this way, a plurality of filter sections 41 and 42 are configured within a single dielectric block 31.

By the way, between the two adjacent filter sections 41 and 42,
That is, the inner conductors 33a, 3 adjacent between both filter tabs
4a, a filter coupling hole 43 is formed in the dielectric block 31. In this filter coupling hole 43,
Adjacent inner conductors 33a.

A capacitively coupled connection terminal 44 is press-fitted into 34a. The connection terminal 44 has a center conductor 448 made of a metal material, and an insulating tube 44b made of synthetic resin fixed around the center conductor 44a.

In this embodiment, the center conductor 44a and the inner conductors 33a, 3
4a are capacitively coupled via a dielectric block portion around the filter coupling hole 43.

Therefore, in the embodiment shown in FIG. 1, the filter section 41 and the filter section 42 are connected to each other by the connection terminal 44, and thereby the connection point 3 shown in the block diagram shown in FIG. has been done. In addition, the center conductor 4 of the connection terminal 44
The portion of the dielectric block 4a extending outside the dielectric block 31 constitutes the common terminal 4 (FIG. 2).

On the other hand, on the other resonator side of each filter section 41, 42,
Input/output pins 46 and 47 are press-fitted into the through holes 32 and 35. The structure of the input/output pins 46.4.7 is similar to the connection terminal 44 described above. In addition, center conductors 46a and 47a
The distance drawn out to the outside of the dielectric block 31 is made equal to the center conductor 44a of the connecting terminal 44, and therefore the dielectric filter device is a three-terminal type dielectric filter device having terminals of equal length as a whole. . Note that this center conductor -
- 46a and 47a constitute the terminals 5a and 5b in FIG.

As is clear from the above description of the configuration, a plurality of filter sections 41 and 42 are configured within the single dielectric block 31. Furthermore, each of the filter sections 41 and 42 has a connecting terminal 4.
They are mutually connected by 4. Therefore, it can be seen that there is no need to prepare a separate dielectric block for each filter as in the conventional filter device 10 shown in FIG. In addition, the through holes 32 in each filter part 41, 42
35, the inner conductors 32a to 35a and the outer conductor 36 can be formed simultaneously.

In the dielectric filter device 30 of the embodiment shown in FIG. 1, as schematically shown in FIG. 3) In the case of a hollow structure, the first stage resonator of the first filter section 41 and the second stage resonator Even if the first-stage resonator of the filter section 42 and the first-stage resonator are excited in opposite phases and try to couple each other, as shown in FIG. 6, the center conductor 448 exists near the position where the magnetic wall Δ is formed. Therefore, the center conductor 44
Since the electric lines of force enter a, each resonator is hardly coupled.

Conversely, when adjacent resonators are excited in the same phase,
As shown in FIG. 7, between the resonators, that is, the inner conductor 33a
, 348, and the rain gear pendulums are no longer coupled to each other.

Therefore, it can be seen that the first and second filter sections 41 and 42 do not affect each other.

Therefore, it can be seen that even if a duplexer having the above-mentioned configuration is configured, the characteristics will not deteriorate due to this. Furthermore, the conventional duplexer design method can be applied as is.

Note that as means for making the center frequencies of the first filter section 41 and the second filter section 42 different, an electrode may be provided on the voltage open end surface side of the filter section with the lower center frequency, or a dielectric material may be used. When forming the block 31, the sizes of the portions constituting each filter section 41, 42 may be made different. Furthermore, the inner diameters of the through holes 32, 33 and 34.
You can also make it 35 and Tatsumi.

Furthermore, the strength of the coupling between the first and second filter sections 4.1.42 and the external circuit (ie, the size of the capacitance formed between the connection terminal 44) is determined by the filter into which the connection terminal 44 is inserted. This can be controlled by adjusting the position of the binding hole 43.

However, when controlling the coupling strength with the external circuit by shifting the position of the filter coupling hole 43, it is necessary to mold the dielectric block using a special mold according to the characteristics and fire it. Therefore, it is necessary to prepare a large number of molds according to various characteristics.

Therefore, preferably, as shown in FIG. 8, the filter part coupling hole 43 is located at the center between both the filter parts 41 and 42, and the filter part coupling hole 43 is located at the center between the two filter parts 41 and 42, so that the filter part coupling hole 43 is located on the side of the filter part where stronger coupling is required (in FIG. Insert the input/output pin 51 into the adjacent through hole 34 on the
may be electrically connected to the center conductor 44a of the connection terminal 44 by the connection member 52. In addition, as the connection member 52, as shown in the figure, a rigid metal pin is used as the rain center conductor 44a.

51a by welding or soldering, or a flexible lead wire may be connected to the rain center conductor 44a, 51.
It may be connected between a.

Furthermore, it has through holes through which the portions of the center conductor 448 and the center conductor 51a drawn out from the dielectric block 31 are inserted, and the through holes are electrically connected to each other by a conductive pattern. By electrically connecting the center conductor/1.4a and the center conductor 51a using a substrate, the coupling strength between the second filter section 42 and the external circuit can be increased to that between the first filter section 41 and the external circuit. The bonding strength may be higher than the bonding strength.

In the dielectric filter device 30 of the embodiment shown in FIG.
may be connected by FIG. 9 is a sectional view showing an example of such a modification. Here, connection terminal 4
A one-stage second filter section 62 is configured on one side of the filter 4.

In the second filter section 62, the coupling hole 63 has an input/output pin 6.
4 is press-fitted. The structure of the input/output pin 64 is similar to the aforementioned input/output pin 47 (see FIG. 1). Also,
The rest of the structure is the same as the dielectric filter device 30 of FIG. 1, so the same reference numerals are given and the explanation thereof will be omitted.

FIG. 10 is a sectional view showing still another embodiment of the invention. In this embodiment, a through hole 72 is formed in the center of the dielectric block 71, and an inner conductor 72a formed on the inner circumferential surface of the through hole 72 and an outer conductor 72a formed on the outer circumferential surface of the dielectric block 71. The conductor 73 constitutes a resonator, and a one-stage bandpass filter is provided using the resonator. On both sides of this through hole 72, filter part coupling holes 74.75 are formed in parallel with each other, and each filter part coupling hole 74.75 is formed in parallel with each other. , 75 has connection terminal 76°77
is press-fitted. The filter portions 74 and 75 and the connecting terminals 76 and 77 are configured similarly to the filter portion coupling hole 43 and the connecting terminal 44 of the embodiment shown in FIG. 1, respectively. Moreover, on the outside of the filter part coupling hole 74.75,
Filter sections 78 and 79 similar to the first and second filter sections 41 and 42 of the embodiment of FIG. 1 are constructed respectively.

Ita of each filter section 78, 79 is the same as the filter section 41, 42 of the embodiment shown in FIG.

In the embodiment shown in FIG. 10, filter sections 78 and 79 are connected to both sides of a one-stage bandpass filter arranged in the center via connection terminals 76 and 77. Therefore, two branch portions are formed by the center conductor 768.77a of the connection terminal 76.77. In each of the embodiments shown in FIGS. 1 to 9, a rectangular parallelepiped dielectric block was used, but as shown in FIG. The dielectric filter device of the present invention can also be configured using the dielectric block 81 of . Further, as shown in FIG. 12, a dielectric block 91 having a step-like shape when viewed from the voltage open end surface side may be used. In this case, the inner conductor on the inner surface of the first stage through hole 94 of the first filter part 92 and the first stage through hole 96 of the second filter part 93
The inner conductor on the inner surface of the dielectric block 91 is capacitively coupled with the connecting terminal 97 at the bent portion of the dielectric block 91 .

As is clear from the examples of FIGS. 11 and 12 described above, when constructing the dielectric filter device of the present invention,
The shape of the dielectric block is not particularly limited.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention. FIG. 2 is a block diagram of a duplexer that forms the background of this invention. 3 and 4 are a perspective view and a partially cutaway front view for explaining an example of a conventional dielectric filter device. 5 is a cross-sectional view of a connecting portion between both filter parts in the embodiment shown in FIG. 1, and FIG. 6 is a schematic diagram for explaining the magnetic wall formed between both filter parts in the embodiment shown in FIG. 1. FIG. 7 is a schematic cross-sectional view for explaining an electric wall formed between both filter parts. FIG. 8 is a sectional view showing a second embodiment of the invention, FIG. 9 is a sectional view showing a third embodiment of the invention, and FIG. 10 is a sectional view showing a fourth embodiment of the invention. It is a sectional view showing an example. FIG. 11 and FIG. 12 are bottom views showing examples in which the shape of the dielectric block is changed, and are views seen from the voltage open end surface side. In the figure, 30 is a dielectric filter device, 31 is a dielectric block, 32 to 35 are through holes, 32a to 35a are inner conductors, 36 is an outer conductor, 4, 1 and 42 are filter parts, and 43 are filter part coupling holes. , 44 indicate connection terminals. =17- Figure 3 +1/1 Figure 4

Claims (3)

[Claims] (1) A single dielectric block in which three or more through holes are formed in parallel to each other, an inner conductor formed on the inner peripheral surface of each of the through holes, and an inner conductor formed on the outer peripheral surface of the dielectric block. and an outer conductor that cooperates with each of the inner conductors to form a resonant unit, a plurality of filter sections are constituted by each of the resonant units, and adjacent among the plurality of filter sections A coupling hole for coupling the adjacent filter parts is formed between adjacent inner conductors of a pair of filter parts, and the coupling hole is inserted into the filter part coupling hole, and the inner conductors of the adjacent filter parts A dielectric filter device further comprising a connection terminal capacitively coupled to the inner conductor. (2) further comprising a conductor member capacitively coupled to the inner conductor of the first-stage resonance unit of one of the adjacent filter sections;
The dielectric filter device according to claim 1, wherein the conductor member is electrically connected to the connection terminal. (3) The dielectric material according to claim 2, wherein the conductor member includes a metal pin and an insulating cylinder fixed around the metal pin, and is press-fitted and fixed into the through hole. filter device.