JP3443084B2 - Symmetrical ceramic resonator and band-pass filter using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a symmetric ceramic resonator and a bandpass filter using the same, and more particularly to a new symmetric ceramic resonator having a small loss coefficient that can be easily coupled and adjusted in any direction. Utilizing a ceramic resonator, a small ceramic resonator for passing / blocking a specified frequency of the GHZ band used in various mobile communication and wireless communication base stations or repeater systems with high attenuation characteristics, And a band pass filter using the same.

[0002]

2. Description of the Related Art A resonator is an inductor in terms of an equivalent electronic circuit.
As a circuit element that resonates at a specific frequency by the combination of (L) and capacity (C), such resonators, that is, microwave ceramic resonators are coupled in multiple stages to adjust the coupling coefficient between the resonators in various ways. , Band pass filter (BPF) with various pass / stop bandwidths, band reject filter (Band Rejecti)
on Filter) and Duplexer can be manufactured.

However, the characteristics and size of the above-mentioned microwave element are determined by the characteristics and sizes of the respective resonators constituting the microwave element, and the overall element characteristics are also determined by the signal transmission method between the resonators. The damping characteristics are affected.

The conventional ceramic resonator 1 is shown in FIGS.
As shown in FIG. 3, through holes 3 are formed in the length direction of a rectangular parallelepiped made of a high dielectric constant ceramic, and a conductive film 5b is formed on the inner / outer surfaces of the body 5. The (shaded portion) 5a has a structure in which the plating is completely removed.

Such a ceramic resonator 1 has one side surface 5
When the conductive film 5b of a is completely removed and the energy radiated to the outside is large, and a bandpass filter (BPF) is constructed using this, as shown in FIG. 3 and FIG. Coupling between the plurality of resonators 1a-1c is first connected to the transmission lines of the printed circuit board 7 through the copper wire cores 11 from the resonators 1a-1c, and the board 7 may be separately provided with a plurality of chip-type capacities. Inductor element (Capacitor
or Inductor) 9 etc. were used for the connection.

Therefore, in the conventional ceramic BPF, the loss factor of the resonator is increased by coupling the resonators externally, and the transmission loss of the BPF is also increased.

Coupling of the resonators 1a-1c
Has to be adjusted by using a tool such as a grinder to peel off the conductive film 5b on the resonator surface little by little, so it becomes difficult to adjust the coupling amount.
It is almost impossible to regenerate the conductive film that was once removed, and there is a problem that the loss increases, and the productivity of BPF is low.

Further, the conventional BPF has a structure in which the conductive film on one side of each resonator is completely removed, and the inner conductive film and the outer conductive film are gradually removed for tuning the resonance frequency. However, since the resonance frequency must be tuned, there are problems such as troublesome frequency tuning work and an increase in the loss factor of the resonator. Therefore, highly skilled workers are required for such work, and it is difficult to freely adjust the frequency tuning range because the reversibility of frequency tuning is not guaranteed.As a result, the tuning range is narrow. There is a problem that becomes.

Further, the conventional metal cavity type bandpass filter, in which a dielectric is floated in a metal cavity to form a resonator, is much larger than a ceramic filter, and the cavity and dielectric There is a limit to reducing the size of the body structure.

On the other hand, the band-pass filter and the band-elimination filter of the transmitting and receiving apparatus require very small insertion loss characteristics and abrupt attenuation characteristics within the stop band.

Therefore, in order to solve such a problem, a new type resonator having a small resonator itself and an excellent loss coefficient characteristic and a band pass filter manufactured by using the resonator are required. ing.

[0012]

SUMMARY OF THE INVENTION Therefore, the present invention has been devised in consideration of the above problems of the prior art. The first object is to provide multistage coupling of resonators and coupling of input / output terminals. It is an object of the present invention to provide a small-sized ceramic resonator having a symmetrical structure which can be easily coupled in any direction.

A second object of the present invention is that the tuning screw is coupled to the through hole of the resonator, the tuning of the resonant frequency is easy, and the minimum conductor film required for tuning the resonant frequency and coupling between the resonators. The purpose of the present invention is to provide a small ceramic resonator having a small loss factor in order to remove only the resonator from the resonator.

A third object of the present invention is to have a structure in which a tuning screw is inserted between the resonators when the resonators are coupled in multiple stages, and the size is small and the transmission loss is small while the coupling capacitance is large. It is an object of the present invention to provide a small-sized ceramic resonator and a band-pass filter which can be adjusted remarkably easily, can be reversibly reproduced, and can reduce the defective rate of products.

A fourth object of the present invention is to easily tune the resonance frequency and to have a wide frequency tuning range, and to remove from the resonator only the minimum conductor film necessary for tuning the resonance frequency and coupling between the resonators. In addition, GHZ required for various mobile communication and wireless communication base stations or repeater systems using multiple small resonators with small loss factors.
It is to provide a small ceramic bandpass filter for passing / stopping specified frequencies in the band.

A fifth object of the present invention is to combine a series of symmetric ceramic resonators having a small loss factor with easy coupling and adjustment between the resonators in any direction, in series / parallel, and to attenuate at a desired frequency within a stop band. It is an object of the present invention to provide a compact ceramic bandpass filter that can pass / block specified frequencies in the GHZ band with high attenuation characteristics by realizing the above.

A sixth object of the present invention is to provide a small ceramic resonance which can be realized as an inexpensive and small element by adding a simple bypass means without increasing the number of stages in order to improve the attenuation characteristic in the stop band. The object is to provide a bandpass filter of the type.

[0018]

In order to achieve the above-mentioned object, the present invention comprises a ceramic material having a high dielectric constant,
A hexahedron-shaped ceramic body having a vertical through hole at its center and at least two vertical cutouts on four side surfaces, and high conductivity on the inner and outer front surfaces of the ceramic body. A conductive coating film coated with a conductive conductive material and having a first coating removal portion formed at the inlet of the inner peripheral portion of the through hole of the ceramic body, and the distal end is movably coupled to the through hole of the ceramic body. A ceramic resonator comprising a resonance frequency tuning means for adjusting the resonance frequency by electromagnetic coupling with the resonator in the first film removing section.

The cut groove forms a cylindrical space into which a tuning screw for adjusting the coupling capacitance between the resonators is inserted at the connecting portion with the adjacent resonators in the multi-stage connection, and the cut grooves are formed in the adjacent cut grooves. Further includes a second film removal portion where the conductive film is selectively and partially removed, and the incision groove is any one of a semi-circular type, a rectangular trench, a notch type and a parabolic shape. It is formed by one.

The cutting groove may further include a third film removing portion in which the conductive film is selectively and partially removed to connect the input / output terminals, and the third film removing portion may be reversed. It is formed by one of a "U" shape and an infinite loop shape.

According to another feature of the present invention, the present invention is a hexahedron shape having an input terminal for receiving a microwave input signal, a through hole formed in the center, and a cutout groove on at least two of the four side surfaces. A high-conductivity conductor is formed on the inside / outside of the ceramic body, and the first conductive film removing portion and the second conductive portion are formed in the incision grooves facing each other between the resonator and the inner peripheral inlet of the through hole. A plurality of first ceramic resonators forming a film removal portion and connected in series so as to output only a signal in a frequency band set from the input signals; and each of the first ceramic resonators is installed in a through hole of the ceramic body. A plurality of resonance frequency tuning means for adjusting the resonance frequency by electromagnetic coupling with the resonator in the first film removing section, and a plurality of resonance frequency tuning means installed in the adjacent facing cut grooves and adjacent to the second film removing section. Was done A plurality of coupling capacitance adjusting means for adjusting the coupling capacitance between the resonators by electromagnetic coupling with the resonator, and an output terminal connected to the final stage resonator and outputting an output signal that has been band-passed. A band pass filter using a ceramic resonator is provided.

Of the plurality of first ceramic resonators, the first-stage and last-stage resonators further include a third film removing portion in which the conductive film is selectively removed because the input and output terminals are connected to the cut groove. The third film removing portion has one of an inverted "U" shape and an infinite loop shape.

In addition, a metal case and a cover in the shape of a rectangular cylinder for accommodating the plurality of ceramic resonators inside and grounding the ceramic resonators are further included, and the plurality of resonance frequency tuning means and the coupling capacitance adjusting means are each made of metal. It is rotatably supported by the cover of the case.

Further, the present invention provides at least one second ceramic resonator connected in parallel to at least one of the plurality of ceramic resonators connected in series to form an attenuation point in a stop band. Further includes.

Further, according to the present invention, at least one or more ceramic resonators are bypassed from the preceding ceramic resonators by the plurality of first ceramic resonators so that the latter ceramic resonators partially bypass the resonance signal. It may be desirable to further include bypass means for forming an attenuation point in the band.

As described above, the resonator according to the present invention has a bilaterally symmetrical structure, and cutouts useful for inserting and adjusting the coupling capacitance are formed on the four outer surfaces of the resonator to form coupling and insertion between the resonators. / It is easy to connect the output terminals regardless of the direction, the resonance frequency can be easily tuned by adjusting the tuning screw, and the conductor film to be removed from the outside of the resonator can be optimized to a minimum to create a small resonator with a small loss coefficient. Can be realized.

Further, according to the present invention, an attenuation point is realized at a desired frequency in the stop band by the series / parallel coupling of the resonators in the limited space, so that the specified frequency in the GHZ band has a high attenuation characteristic. It can be passed / blocked by a simple bypass means without increasing the number of stages, so that it can be realized as an inexpensive and small element.

The above-described object of the present invention and other features and advantages will be apparent from the following description of the preferred embodiments of the present invention to be referred to next.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention described above will be described in more detail with reference to the accompanying drawings. FIGS. 5 to 7 attached are an exploded view, an assembled view and a fully assembled view with a cover removed, showing a basic band pass filter used in the present invention.
FIG. 1 is a plan view showing a ceramic resonator type bandpass filter having excellent attenuation characteristics according to a first embodiment of the present invention.

First, referring to FIG. 21, the first aspect of the present invention will be described.
Ceramic resonator type bandpass filter (BPF) according to an embodiment
Are six serially connected first to sixth ceramic resonators 20a-20f, and first and sixth ceramic resonators 20a, 20a,
20f each connected in parallel to upper and lower damping points UNP, LNP
It is composed of two seventh and eighth ceramic resonators 20g and 20h for forming the.

The first to sixth ceramic resonators 20a to 20f connected in series have a structure for providing a bandpass characteristic in a BPF, and are connected in parallel to the seventh and eighth ceramic resonators 20g, 20g. 20h plays a role of forming an attenuation point by coupling the energy of the frequency corresponding to each resonance frequency and by-passing with the ground.

The ceramic resonator 20a-2 described above is provided to assist in understanding the BPF of the present invention described below.
The structure for each of the 0h, the interconnection structure between them, and the basic type ceramic bandpass filter using them will be sequentially described.

The single ceramic resonator 20 used in the present invention is made of a ceramic material having a high dielectric constant, as shown in FIGS. 8 to 12, and has a shape of a regular hexahedron or a rectangular parallelepiped. 4 through holes 22
On the inner and outer surfaces of the ceramic body 21 having vertical cutouts 23a-23d formed on its side surface, a conductor having excellent conductivity, for example, a conductive film 24 of silver, copper, aluminum or the like.
Has a plated structure.

The length of the through hole 22 of the resonator 20 is set to λ / 4 of the resonance frequency, and the size of the resonator can be reduced by using a high dielectric constant ceramic material. .

The cut-out grooves 23a-23d are formed in a semi-circular shape, and when a multi-stage connection is made, a cylindrical space is formed in a connecting portion with an adjacent resonator, as will be described later. It is desirable that the adjustment tuning screw 32 can be easily inserted in a limited space. However, the incision grooves 23a-23d are not limited to this, and may have another shape, for example, a spherical trench.
A trench, a notch type, a parabolic shape, etc. are also possible.

Further, the ceramic resonator 20 of the present invention is
Inside one side of the through hole 22 for adjusting the resonance frequency,
As shown in Figs. 5 and 12, the tuning screw (2
6, 26a-26c), the conductive film 24 is formed due to the electromagnetic coupling between the metal rod 40 which is the tip portion of the wire 26 and the resonator and the resonator.
The first film removing portion 25 in which is partially removed only in the upper part
The metal rod 40 of the tuning screw 26 is inserted into the through hole 22. The ceramic resonator described above forms an LC parallel resonant circuit in an equivalent circuit.

Therefore, the ceramic resonator 2 of the present invention
With 0, the resonance frequency of the resonator can be easily adjusted by rotating the tuning screw 26 from the outside and inserting the metal rod 40 into the through hole 22.

In this case, in the present invention, the loss due to energy radiation can be minimized because the first film removing portion 25 for adjusting the resonance frequency in each resonator is removed from the conductive film 24 to the minimum.

On the other hand, FIGS. 5 to 7 show a basic type BPF (50) used in the present invention, which is formed by connecting three ceramic resonators 20a-20c in series.

In the basic form BPF 50, a cylindrical space 31 formed by the cut grooves 23b and 23d adjacent to each other.
Is the coupling capacitance between the resonators 20a and 20b and 20b and 20c.
ingCapacitance), that is, a tuning screw 32 for adjusting the coupling capacity, into which a metal rod at the tip end is inserted in order to adjust the coupling coefficient, is movably coupled to the metal plate (cover) 27. The tuning screw 32 for adjusting the coupling capacity is used to determine the pass band width of the BPF 50.

5 to 7, the member number 33 is a fixing nut for fixing the resonance frequency adjusting tuning screws 26a-26c or the coupling capacity adjusting tuning screw 32 at a set position, and 34 is a ceramic resonator. A metal case for accommodating and supporting 20a-20c, 35 is an input terminal, 36 is an output terminal, and 37 is a cover fixing screw.

Cutting grooves 23a-23d of the resonator 20 described above
As shown in FIG. 13, the conductive film 24 is removed from any one, two, or three incision grooves of the resonator for electromagnetic coupling with the adjacent resonators when the resonators are connected in series / parallel. 2 The film removal portion 28 is formed.

Referring again to FIGS. 5 to 7, the second film removing portion 28 described above has cutout grooves 23b and 23d facing each other between two resonators 20a and 20b connected adjacent to each other.
Are formed at the same position.

Further, in the second film removing portion 28, as shown in the example of FIG. 16, the tuning screw 32a for adjusting the coupling capacity is the tuning screws 26a-26c for adjusting the resonance frequency.
Resonator 2 when coupled from the opposite direction, ie from below
It is formed below the incision grooves 23b and 23d of 0a-20c.

In this case, the tuning screw 32a for adjusting the coupling capacity is rotatably fixed to the case or the support plate 34a so that the tip of the tuning screw 32a moves up and down in the cylindrical space 31 inside the cutting grooves 23b and 23d.

Therefore, the resonators 20a and 20b and 20b and 20c adjacent to each other through the second film removing portion 28 are electromagnetically coupled to each other so that electromagnetic energy is propagated between the resonators, that is, capacitive coupling is performed. It If the tuning screws 32 and 32a are rotated from the outside in this state, the amount of energy propagated is adjusted by the extent to which the tip of the tuning screw descends and is inserted into the cylindrical space 31, and the coupling capacity is adjusted. The value is variable.

As a result, in the present invention, the structure for adjusting the coupling capacitance between the resonators is formed inside the resonator and can be accommodated in the minimum space, and the coupling capacitance is generated by the rotation of the tuning screws 32 and 32a. Can be adjusted easily and reversibly.

Further, in the case of the example shown in FIG. 5, the first film removing portion 25 formed in the through hole 22 is formed at a portion to which the resonance frequency adjusting tuning screws 26a-26c are coupled. Of course, it is also possible to form the tuning screws 26a-26c in the opposite through hole 22 to which the tuning screws 26a-26c are coupled, as in the example of FIG.

The above-mentioned examples shown in FIGS. 5 to 7 show BPFs 50 connected in series in three stages, but each resonator 20a-20c has a symmetrical structure with respect to four directions. For this reason, a bandpass filter (BPF) connection having a modified structure in any direction as in the first embodiment shown in FIG. 21 is possible.

On the other hand, FIGS. 14 and 15 show a ceramic resonator of the present invention, that is, an external connection structure for coupling input / output terminals to a BPF, respectively, a ground structure and an open structure.
The (open) structure is shown.

First, the connection between the ceramic resonators 20a, 20c and the input / output terminals 35, 36 is reversed "U" in the vertical direction in the cut groove 23d or 23b as shown in FIG.
Third film removing portion 29 in which the conductive film 24 is removed in a V shape
Is used. When the input / output terminals 35 and 36 are connected to the upper stage of the third film removing portion 29, the third film removing portion 29 is an equivalent circuit, and the final stage is grounded. Inductor coupling (L-Coupling) structure And protects the device in the subsequent stage when a DC and low frequency lightning strike is received through the antenna.

The connection between the ceramic resonators 20a, 20c and the input / output terminals 35, 36 is provided with a conductive film 24 in an infinite loop shape in the vertical direction in the cutout groove 23d or 23b as shown in FIG. Removed fourth film removal unit 30
Can be used. When the input / output terminals 35, 36 are connected to the Irish portion inside the fourth film removing section 30 and viewed as an equivalent circuit, the capacity between the input / output terminals 35, 36 and the internal circuit of the filter 50 is opposite. City coupling
(C-Coupling) structure is formed. Therefore, the user can selectively employ the coupling structure as needed.

On the other hand, the tuning screw 3 described above
As shown in FIG. 17, the support plate 34a supporting 2a is integrally formed with three support poles 41 for positioning and supporting the resonators 20a-20c on the upper side. The plate 34a is provided with a support nut 42 for screwing the tuning screw 32a from below.
Is formed with a concave groove 34b.

Tuning screws 26, 26a-26c, 32, 32 for adjusting resonance frequency and coupling capacitance of the present invention
18, the tuning screw 26, 26a-26c, 32, 32a is provided with a support nut 42 so that the tuning screw 26, 26a-26c, 32, 32a is rotatably supported by the case 34 or the support plate 34a as shown in FIG. It is desirable that the case 34 or the support plate 34a is fixedly installed in the groove 34b of the support plate 34a.

Further, according to the present invention, unlike the modification shown in FIGS. 19 and 20, the resonators 20a-20c and the tuning screw block 44 are sequentially assembled on the substrate 43 directly without using a metal case. It is also possible to do so.

In this case, the tips of the input / output terminals 35a and 36a are supported by the substrate 43, and the tips thereof are respectively resonators 20a and 20a.
It is connected to the third film removing section 29 or the fourth film removing section 30 of 0c.

Further, in the above example, the resonators 20a-20c and the tuning screw block 44 were assembled vertically to the substrate 43, but the tuning screw block 44 should be mounted sideways on the substrate 43 so as to be located on the side surface. Is also possible.

Further, in addition to the method of fixing the input / output terminals 35a and 36a to the substrate 43 and connecting them to the resonators 20a and 20b, the third or fourth film removing portion 2 of the resonators 20a and 20c.
It is also possible to assemble directly by attaching directly to 9,30.

As described above, in the band pass filter (BPF) according to the first embodiment of the present invention, the resonance frequency is tuned and the coupling capacitance between the resonators is adjusted by the plurality of ceramic resonators 20a-20h connected in series. A filter that is easy and has a desired bandpass characteristic can be easily constructed.

Further, in this case, the loss coefficient and size of each resonator are small, and a low loss filter is realized in a compact size because a condenser and the like necessary for coupling the resonators are not separately provided. You can

Further, according to the present invention, as shown in FIG. 21, a plurality of ceramic resonators 20a-20f connected in series are connected in parallel to the ceramic resonators 20g, 20h as shown in FIG. The upper and lower attenuation points UNP and LNP can be formed at the desired stopband frequency.

In this case, a tuning screw for adjusting the resonance frequency is coupled to the through holes 22a-22h of the resonators 20a-20h connected in series / parallel to adjust the coupling capacitance between the resonators. Seven tuning screws for adjusting the coupling capacity are connected to the cylindrical spaces 31a-31h.

In addition, the number of ceramic resonators connected in parallel with the ceramic resonators connected in series and the parallel connection position in the above-mentioned embodiment can be changed by the bandpass characteristic of the BPF, and a limited number of resonators are used. In this case, the series / parallel connection pattern of the resonator may be variously modified because the resonator has a symmetrical structure in four directions.

FIG. 23 shows a ceramic resonator type bandpass filter 50a capable of forming an attenuation point by using the bypass coaxial cable according to the second embodiment of the present invention, which is used in the stopband without increasing the number of resonator stages. 3 shows a structure capable of forming an attenuation point.

As shown, the BPF 50a according to the second embodiment of the present invention has first to fourth ceramic resonators 20a-20d connected in series, for example, the first and fourth ceramic resonators 20a, 20d. Through holes 61a, 6
1b is formed, a coaxial cable 62 is used between the through hole 61a and the through hole 61b, and both core wires 62a and 62b of the coaxial cable 62 are inserted and coupled.

In this case, the coaxial cable 62 may be installed by being embedded in the accommodation groove formed in the cover when it is built in the case, or may be entirely constructed without the case. Is.

Of course, in this case as well, a tuning screw for adjusting the resonance frequency is coupled to the through holes 22a-22d of the first to fourth ceramic resonators 20a-20d.
A tuning screw for adjusting coupling capacity is coupled to the cylindrical space 31a-31c between the first to fourth ceramic resonators 20a-20d.

In the second embodiment constructed as described above, the resonance frequency adjusting tuning screw and the coupling capacity adjusting tuning screw of each of the resonators 20a-20d are appropriately set so that the pass band having a desired bandwidth can be obtained. To set.

In this case, in the second embodiment, the input signal is the first
After being input to the ceramic resonator 20a and resonating in the primary, the signal resonated in the primary resonates with the second ceramic resonator 20b.
A part of the signal that has been transmitted to the second resonance and simultaneously has the second resonance is electromagnetically induced in the coaxial cable 62. After that, the signal that has undergone the primary resonance is bypassed without passing through the second and third ceramic resonators 20b and 20c, and then the fourth signal is obtained.
It is supplied to the ceramic resonator 20d.

As a result, in the fourth ceramic resonator 20d, the band-pass signal passing through the first to third ceramic resonators 20a-20c and the bypassed signal are mixed, and the frequency of the adjacent channel is greatly attenuated in this process. The action occurs.

Through the above process, the output signal obtained from the fourth ceramic resonator 20d is a signal that is abruptly attenuated in the upper stop band and the lower stop band of the pass band. That is, in the frequency characteristic curve of the BPF according to the second embodiment, the attenuation points UNP and LNP are formed in the upper / lower stopbands, respectively, and bandpass filtering is obtained in which the attenuation is performed rapidly.

In the above description of the embodiments, the resonator of the present invention is applied to a band pass filter as an example, but other than this, a unit ceramic such as a band stop filter or a duplexer is used. Any microwave component that can be formed by combining resonators can be applied.

Further, in the above embodiment, an example in which the cutting groove is formed in the same direction as the through hole and the tuning screw for adjusting the coupling capacity is also combined in the vertical direction is shown. Of course, the screw can also be formed horizontally by the coupling direction with the adjacent resonator.

Further, the incision groove may be formed by combining pairs of incision grooves facing each other in the horizontal direction and the vertical direction, if necessary.

The band-pass filter of the present invention can be combined with two or more of them to form another microwave element such as a channel combiner or a duplexer.

[0076]

As described above, in the resonator of the present invention, the resonance frequency can be easily tuned by simply adjusting the tuning screw as compared with the conventional ceramic resonator, and the conductor film to be removed outside the resonator can be minimized. It is possible to realize a resonator with a small loss coefficient by optimizing as much as possible, and a cut groove useful for inserting and adjusting a coupling capacitance is formed on the four outer surfaces of the resonator as a left-right symmetric structure. Connection between the input and output terminals can be easily performed regardless of the direction. As a result, the resonator of the present invention can be significantly reduced in size by about 1/7 compared with the conventional metal cavity resonator type product and the dielectric resonator type product.

Further, the band pass filter of the present invention can tune the resonance frequency simply and quickly when compared with the conventional ceramic filter, and has a coupling capacitance tuning screw built in between the resonators. Therefore, it is possible to make the product compact.

Further, the loss of each resonator is small and the overall transmission loss of the filter is small, so that the input / output terminals can be easily connected in any direction, and the interconnection of the resonators can be made easily. Various types of filters can be constructed in various directions.

Further, in the present invention, an attenuation point is realized at a desired frequency in the stop band by the series / parallel coupling of the resonators in the limited space, so that the specified frequency in the several hundred MHz to several GHz band can be obtained. It can be passed / blocked with high attenuation characteristics, and can be realized as an inexpensive and small element by adding a simple bypass means without increasing the number of stages.

Although the present invention has been described in detail with reference to the embodiments, the present invention is not limited to the embodiments and deviates from the spirit and the spirit of the present invention as long as it has ordinary knowledge in the technical field to which the present invention belongs. Without modification, the present invention could be modified or changed.

[Brief description of drawings]

FIG. 1 is a sectional view of a conventional rectangular parallelepiped ceramic resonator.

FIG. 2 is a perspective view of a conventional rectangular parallelepiped ceramic resonator.

3 is a front view showing a bandpass filter using the ceramic resonator shown in FIG. 1. FIG.

4 is a side view showing a bandpass filter using the ceramic resonator shown in FIG. 1. FIG.

FIG. 5 is an exploded view showing a basic type bandpass filter used in the present invention.

FIG. 6 is an assembly view with a cover removed.

FIG. 7 is a complete assembly view with the cover removed.

FIG. 8 is a perspective view of the small ceramic resonator shown in FIG.

9 is a front view of the miniature ceramic resonator shown in FIG. 5. FIG.

10 is a side view of the small ceramic resonator shown in FIG.

11 is a cross-sectional view taken along the line IV-IV of FIG.

FIG. 12 is an exploded view showing a structure in which a tuning screw is coupled to a ceramic resonator.

FIG. 13 is a view showing a structure of an outer surface when a ceramic resonator is connected in multiple stages.

FIG. 14 is a front view of a ground structure as an external structure when the input / output terminals are coupled to the ceramic resonator.

FIG. 15 is a front view of an open structure as an external structure when the input / output terminals are coupled to the ceramic resonator.

FIG. 16 is an exploded view of a modified basic bandpass filter used in the present invention.

17 is a cross-sectional view of a support plate used to support the resonator in FIG.

FIG. 18 is an exploded view of the tuning screw support assembly used in the present invention.

FIG. 19 is an exploded view of another modified basic bandpass filter used in the present invention.

FIG. 20 is an assembly diagram showing another modified basic bandpass filter used in the present invention.

FIG. 21 is a plan view showing a ceramic resonator type bandpass filter having excellent attenuation characteristics according to the first embodiment of the present invention.

FIG. 22 is a graph schematically showing bandpass frequency characteristics of the first example.

FIG. 23 is a plan view showing a ceramic resonator type bandpass filter capable of forming an attenuation point using a bypass coaxial cable according to a second embodiment of the present invention.

[Explanation of symbols]

20, 20a-20h Ceramic resonator 21 Ceramic body 22, 22a-22h Through hole 23a-23d Cut groove 24 Conductive film 25 First film removing portion 26, 26a-26c, 32, 32a, 67a-67c Tuning screw 27 Cover 28 Second film removing unit 29 Third film removing unit 30 Fourth film removing unit 31, 31a-31h Cylindrical space 33 Fixing nuts 34, 34b Metal case 34a Support plate 34b Grooves 35, 35a Input terminals 36, 36a Output terminal 37 fixing Screw 40 Metal rod 41 Support pole 42 Support nut 43 Substrate 44 Tuning screw block 50, 50a Band pass filter 61a, 61b Through hole 62 Coaxial cable 62a, 62b Core wire

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Dar Ahn Korea, Choon Chunnam-do, Chunan-si, Susan Yong-Dong 1923, Yong Am Don Abak San Apartment 107-303 (72) Inventor Chur・ San Yong Republic of Korea, Kyun Ked, Suwon Si, Pardal Kuk, Yong Tong Dong 969-1 Samsung Apartment 922-1402 (72) Inventor Jae Ho Lee South Korea, Kun Ked, Suwon Si, Paldal-Ku, Won Chun-Dong 256-5 Sung-Dong Apartment A-201 (72) Inventor John Chur Park South Korea, Kyun Ked, Su Won-shi, Pal D'Ark, Methan 1-Dong, Dugong 1 Dunge APA Statement 31-104 (72) Inventor Jae Bok Lee Korea, Choeng Chunnam-do, Chunan-si, Susan Yong-dong 1367, Wolbong Chun-Sol Apartment 102-1003 (72) Inventor Jun Suk・ Park Republic of Korea, Choeng Chunnam-do, Chunan-si, Sinbang-dong 903, Samilwonan Apartment 102-1306 (72) Inventor Hong Seung-jo, Republic of Korea, Kunkied, Suwon-si, Paldar-ku , Manpo-don 447-5, Johnson Jutek 5-20 (56) Reference JP-A-7-245506 (JP, A) JP-A-11-214905 (JP, A) Jitsukaihei 4-4403 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01P 1/20-1/219 H01P ^7/ 00-7/10

Claims (15)

(57) [Claims] 1. A ceramic material having a high dielectric constant,
A hexahedron-shaped ceramic body having a vertical through hole at its center and at least two vertical cut grooves on four side surfaces, and high conductivity on inner and outer surfaces of the ceramic body. Is coated with an electrically conductive material, and the first inner surface of the through hole of the ceramic body
A resonance for adjusting the resonance frequency by electromagnetically coupling the resonator to the resonator in the first film removal unit, the tip being movably coupled to the through hole of the ceramic body, and the conductive film having the film removal unit formed therein. A frequency tuning means, and the incision groove is a connecting portion with an adjacent resonator at the time of multistage connection.
In addition, there is a tuning switch for adjusting the coupling capacitance between the resonators.
Form a cylindrical space into which the clew is inserted and
The second skin in which the conductive film is selectively partially removed in the open groove
A ceramic resonator, wherein a film removal portion is formed . 2. The conductive film is selectively and partially removed to connect the input / output terminals to the cut groove.
The ceramic resonator according to claim 1, further comprising a film removal portion. 3. The ceramic resonator according to claim 2 , wherein the third film removing portion has one of an inverted “U” shape and an infinite loop shape. 4. A hexahedral ceramic body having an input terminal for receiving a microwave input signal and a through hole formed in the center thereof and having cutout grooves on at least two side surfaces of the four side surfaces. Forming a film of a conductor, and forming a first conductive film removing portion and a second conductive film removing portion in facing cut grooves between the resonator and the inner peripheral portion inlet of the through hole,
A plurality of first ceramic resonators connected in series so as to output only a signal in a frequency band set from the input signals; and the first ceramic resonators installed in through holes of the ceramic body, respectively.
A plurality of resonance frequency tuning means for adjusting the resonance frequency by electromagnetic coupling with the resonator in the film removing section, and a resonance installed in the adjacent cut grooves adjacent to each other and adjacent to the second film removing section. And a plurality of coupling capacitance adjusting means for adjusting the coupling capacitance between the resonators by electromagnetic coupling with the resonator, and an output terminal connected to the final stage resonator and outputting the band-passed output signal. A band-pass filter using a ceramic resonator. 5. A coupling capacitance adjusting means each said plurality of resonant frequencies tuning means comprises a metal body, according to claim tip, characterized in that it is constituted by a tuning screw which is inserted movably in the internal bore 4 A bandpass filter using the ceramic resonator according to claim 1. 6. The band using the ceramic resonator according to claim 4 , wherein each of the plurality of resonance frequency tuning means is installed on the opposite side of the through hole in which the first film removing portion is formed. Pass filter. 7. The first-stage and last-stage resonators of the plurality of first ceramic resonators each have a third film removing portion in which a conductive film is selectively removed because input and output terminals are connected to the cut grooves. The band pass filter using a ceramic resonator as set forth in claim 4 , further comprising: the third film removing portion is one of an inverted "U" shape and an infinite loop shape. 8. A rectangular cylindrical metal case for accommodating the plurality of ceramic resonators and grounding the ceramic resonators and a cover, wherein the plurality of resonance frequency tuning means and the coupling capacitance adjusting means are respectively metal cases. The band pass filter using a ceramic resonator according to claim 4 , wherein the band pass filter is rotatably supported by the cover. 9. A quadrangular cylindrical metal case for accommodating and grounding the plurality of first ceramic resonators and a cover are further included, and the plurality of resonance frequency tuning means are respectively provided on the covers of the metal cases. The bandpass filter using a ceramic resonator according to claim 4 , wherein the bandpass filter is rotatably supported, and each of the plurality of coupling capacitance adjusting means is rotatably supported on a lower end surface of the case. 10. The apparatus further comprises a substrate for supporting the plurality of first ceramic resonators on the upper portion and grounding the first ceramic resonators, wherein the input terminal and the output terminal are directly connected to the cut grooves of the first-stage and last-stage resonators. A band pass filter using the ceramic resonator according to claim 4 . 11. The apparatus further includes at least one second ceramic resonator connected in parallel to at least one of the plurality of ceramic resonators connected in series to form an attenuation point in a stop band. A band pass filter using the ceramic resonator according to any one of claims 4 to 10 . 12. The second ceramic resonator is connected in parallel to a first-stage ceramic resonator, which receives an input signal, and a final-stage ceramic resonator, which generates an output signal, among a plurality of first ceramic resonators. A bandpass filter using the ceramic resonator according to claim 11 . 13. A plurality of first ceramic resonators bypass at least one or more ceramic resonators from a preceding ceramic resonator to bypass a part of a resonance signal to a subsequent ceramic resonator and attenuate the signal in a stop band. the band-pass filter utilizing a ceramic resonator according to any of claims 4 to 10, characterized in that it further includes a bypass means for forming a point. 14. The method of claim 13 wherein the bypass means, characterized in that the core wire at both ends in the through holes of the upstream and downstream ceramic resonator is constituted by a coaxial cable coupled
A bandpass filter using the ceramic resonator according to claim 1. 15. A metal case for accommodating the plurality of ceramic resonators and grounding the ceramic resonators, the case being integrally formed on a bottom surface of the metal case to set the plurality of first ceramic resonators. claim 13, characterized in that it comprises a plurality of support poles for locating set to the position
A bandpass filter using the ceramic resonator according to claim 1.