KR102378832B1 - Cavity filter and method of manufacturing the same - Google Patents

Abstract

A cavity filter that does not require a frequency tuning process is provided. Such a cavity filter includes a housing, a lower resonator and a cover plate. The housing includes a lower plate and a side wall portion extending upwardly from the lower plate. At least one lower portion of the resonator is disposed inside the housing. The cover plate is coupled to the side wall portion of the housing to cover the housing. The cover plate includes a resonator plate and a tuning plate. The resonator plate includes an upper portion of the resonator that is in contact with the lower portion of the resonator and constitutes the resonator. The tuning plate faces to be insulated from the upper part of the resonator, and includes a metal pattern formed to fine tune the frequency of the resonator.

Description

Cavity filter and manufacturing method thereof

The present invention relates to a filter and a method for manufacturing the same, and more particularly, to a cavity filter and a method for manufacturing the same.

A filter is a passive circuit that passes only a desired frequency among input frequency components and attenuates the rest.

These filters, depending on the band pass characteristics, include a high pass filter (HPF) that passes only high frequencies, a low pass filter (LPF) that passes only low frequencies, a band pass filter (BPF) that passes only frequencies of a specific band, and only frequencies of a specific band. It can be divided into a band-stop filter (BSF) that blocks it.

In addition, depending on the implementation form, such a filter is a lump filter formed by combining LC elements, a strip filter using a patterned transmission line, a ceramic filter using a high dielectric ceramic, a cavity filter using a waveguide, and SAW using an acoustic wave. It can be divided into

Among them, a cavity filter is widely used in a filter requiring high power, such as a wireless communication base station. In a conventional cavity filter such as Republic of Korea Patent Registration No. 10-2040689, "cavity filter," a tuning bolt is widely used for frequency tuning. 1 is a side cross-sectional view of a conventional cavity filter in which tuning is performed using a tuning bolt.

Referring to FIG. 1 , in the conventional cavity filter 200 , the resonance element 220 is disposed inside a housing 210 , and a cover 230 is coupled to the housing 210 on the upper portion to define an internal space. On the other hand, the frequency is selected by the connection of these internal spaces.

At this time, the screw threaded tuning bolt 240 is fastened to the cover 230 , and as the tuning bolt 240 is rotated, the spacing between the tuning bolt 240 and the resonance element 240 is changed. Thus, the capacitance between the tuning bolt 240 and the resonance element 2400 is changed to tune the resonance frequency of the cavity filter 200 .

However, in the case of such a conventional cavity filter, as a tuning process of the resonance frequency is required, it is difficult to manufacture.

Republic of Korea Patent No. 10-2040689

Accordingly, an object of the present invention is to provide a cavity filter that does not require a frequency tuning process.

In addition, another problem to be solved by the present invention is to provide a method for manufacturing such a cavity filter.

A cavity filter according to an exemplary embodiment of the present invention for solving these problems includes a housing, a lower part of the resonator, and a cover plate. The housing includes a lower plate and a sidewall portion extending upwardly from the lower plate. At least one lower portion of the resonator is disposed inside the housing. The cover plate is coupled to the side wall portion of the housing to cover the housing. The cover plate includes a resonator plate and a tuning plate. The resonator plate includes an upper portion of the resonator that is in contact with the lower portion of the resonator and constitutes the resonator. The tuning plate faces to be insulated from the upper part of the resonator, and includes a metal pattern formed to fine tune the frequency of the resonator.

For example, the resonator plate may further include a resonator substrate, and the upper portion of the resonator may be attached to a lower surface of the resonator substrate.

For example, the resonator plate may further include a filling tape, and the filling tape may be attached to a lower surface of the resonator substrate to surround the upper part of the resonator.

Meanwhile, the tuning plate may include a substrate and a lower pattern. The lower pattern may be formed on a lower surface of the substrate to constitute the metal pattern.

In addition, the tuning plate may further include an upper pattern. The upper pattern may be formed on the upper surface of the substrate to correspond to the lower pattern to constitute the metal pattern.

For example, the upper pattern and the lower pattern may be connected via vias.

In addition, the tuning plate may further include an upper filling tape or an upper shielding part. The upper filling tape or the upper shielding part may be attached to the upper surface of the substrate to surround the outer side of the upper pattern.

In addition, the tuning plate may further include a lower filling tape or a lower shielding unit. The lower filling tape or the lower shielding part may be attached to a lower surface of the substrate to surround the outer side of the lower pattern.

In a cavity filter manufacturing method according to an exemplary embodiment of the present invention, a resonator plate including an upper portion of a resonator constituting a resonator in contact with a lower portion of the resonator, and facing so as to be insulated from the upper portion of the resonator, fine-tuning the frequency of the resonator Preparing a cover plate including a tuning plate including a metal pattern formed so that preparing a housing; coupling the cover plate and the housing so that the upper surface of the lower part of the resonator and the upper surface of the resonator plate are in contact; determining whether fine tuning is required; and when fine tuning is required, It includes the step of performing fine tuning.

For example, the fine tuning may be performed by pressing the metal pattern of the tuning plate.

Meanwhile, the tuning plate includes a substrate, a lower pattern formed on the lower surface of the substrate and constituting the metal pattern, and an upper pattern formed on the upper surface of the substrate to correspond to the lower pattern and constituting the metal pattern. can do.

For example, the fine tuning may be performed by removing a portion of the upper pattern.

As described above, in the cavity filter according to the present invention, a cover plate having a precisely controlled capacitance with the resonant element is attached, thereby eliminating the need for an additional tuning process using a conventional tuning bolt. That is, in the cavity filter according to the present invention, a tuning process is not required because the overlapping area between the resonant element and the lower surface tuning pattern is precisely controlled for repetitive production of samples.

However, when fine tuning is required due to a process error, the resonance frequency can be tuned by pressing the metal pattern.

On the other hand, when the lower pattern constituting the metal pattern and the upper pattern constituting the metal pattern are electrically connected by a via, and the upper pattern constituting the metal pattern is formed, a portion of the upper pattern is removed without separating the cover plate from the housing By doing so, the resonant frequency can be tuned.

In addition, since the lower shielding part and the upper shielding part shield the lower pattern and the upper pattern, respectively, interference with the neighboring lower and upper patterns may be minimized.

1 is a side cross-sectional view of a conventional cavity filter in which tuning is performed using a tuning bolt.
2 is a side cross-sectional view of a cavity filter according to an exemplary embodiment of the present invention.
3 is a side cross-sectional view of a cavity filter according to an exemplary embodiment of the present invention.
FIG. 4 is a perspective view showing the inside of the housing to which the lower part of the resonator shown in FIG. 2 or 3 is fastened;
FIG. 5 is an exploded perspective view of the cover plate of FIG. 2 , wherein the resonator plate and the tuning plate of FIG. 2 are disassembled.
6 is a flowchart illustrating a cavity filter manufacturing method according to an exemplary embodiment of the present invention.
FIG. 7 is a partial cross-sectional view illustrating an embodiment of performing the fine tuning shown in FIG. 6 .

Since the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements. In the accompanying drawings, the dimensions of the structures may be exaggerated than in reality for clarity of the present invention.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification is present, and includes one or more other features or It should be understood that the existence or addition of numbers, steps, operations, components, parts, or combinations thereof does not preclude the possibility of addition. In addition, A and B are 'connected' or 'coupled' means that A and B are connected or combined because other components C are included between A and B in addition to A and B being directly connected or bonded. that will include

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not Further, in the claims of the method invention, the respective steps may be interchanged in their order unless the respective steps are explicitly constrained to the order.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

2 is a side cross-sectional view of a cavity filter according to an exemplary embodiment of the present invention. 3 is a side cross-sectional view of a cavity filter according to an exemplary embodiment of the present invention. 4 is a perspective view showing the inside of the housing to which the lower part of the resonator shown in FIG. 2 or 3 is fastened; FIG. 5 is an exploded perspective view of the cover plate of FIG. 2 , wherein the resonator plate and the tuning plate of FIG. 2 are disassembled.

2 to 5 , the cavity filter 100 according to an exemplary embodiment of the present invention includes a housing 110 , a lower resonator 120 , and a cover plate 220 .

The housing 110 includes a lower plate 111 and a side wall portion 112 extending upwardly from the lower plate 111 . For example, the lower plate 111 may be formed in a rectangular shape. However, it may be formed in various shapes as needed. The lower plate 111 and the side wall portion 112 may be integrally formed, but may be separately manufactured and combined. The housing 110 may be formed of, for example, metal.

At least one of the resonator lower portions 120 is disposed inside the housing 110 . The resonator lower part 120 may be formed integrally with the housing 110 in a cylindrical shape, for example, or may be formed separately and then coupled thereto.

The cover plate 220 is coupled to the side wall portion 112 of the housing 110 to cover the housing 110 . The cover plate 220 includes a resonator plate 130 and a tuning plate 140 .

The resonator plate 130 includes a resonator upper portion 131 that is in contact with the resonator lower portion 120 and constitutes the resonator 210 . The upper part of the resonator 131 is, for example, a circular disk shape, and is formed to be larger than the diameter of the lower part of the resonator 120 . The diameter of the upper part of the resonator 131 is already tuned according to the required frequency, and fine tuning for the frequency may be performed later.

The upper part of the resonator 131 and the lower part of the resonator 120 may be coupled by solder, in addition to simple contact. In this case, the resonator plate 130 and the side wall portion 112 of the housing 110 may also be coupled by solder.

Meanwhile, the resonator plate 130 may further include a resonator substrate 133 , and the upper portion 131 of the resonator may be attached to a lower surface of the resonator substrate 133 .

For example, the resonator plate 130 may be etched by attaching a metal thin film to the resonator substrate 133 to form the resonator upper part 131 .

Meanwhile, as shown in FIG. 2 , the resonator plate 130 may further include a filling tape 132 , wherein the filling tape 132 surrounds the upper part 131 of the resonator, the resonator It may be attached to the lower surface of the substrate 133 . The filling tape 132 may remove a step difference between the upper part of the filler 131 and the resonator substrate 133 .

The tuning plate 140 faces the upper part of the resonator 131 to be insulated, and includes a metal pattern formed to fine tune the frequency of the resonator 210 . The metal pattern may include at least one of the lower pattern 141 and the upper pattern 143 .

Meanwhile, the tuning plate 140 may include a substrate 142 and the lower pattern 141 . The lower pattern 141 may be formed on the lower surface of the substrate 142 to constitute the metal pattern.

In addition, the tuning plate 140 may further include the upper pattern 143 . The upper pattern 143 may be formed on the upper surface of the substrate 142 to correspond to the lower pattern 141 to constitute the metal pattern.

For example, the upper pattern 143 and the lower pattern 141 may be connected by a via 146 .

In addition, the tuning plate 140 may further include an upper filling tape 145 or an upper shielding part 148 as shown in FIG. 3 , as shown in FIG. 2 . The upper filling tape 145 or the upper shielding part 148 may be attached to the upper surface of the substrate 142 to surround the outer side of the upper pattern 143 .

In addition, the tuning plate 140 may further include a lower filling tape 144 as shown in FIG. 2 or a lower shielding part 147 as shown in FIG. 3 . The lower filling tape 144 or the lower shielding part 147 may be attached to the lower surface of the substrate to surround the outer side of the lower pattern.

As described above, since the lower shielding part 147 and the upper shielding part 148 respectively shield the lower pattern 141 and the upper pattern 143 , interference with the neighboring lower and upper patterns may be minimized.

6 is a flowchart illustrating a cavity filter manufacturing method according to an exemplary embodiment of the present invention.

6, according to the cavity filter manufacturing method according to an exemplary embodiment of the present invention, first, a resonator plate including a resonator upper portion constituting the resonator in contact with the lower portion of the resonator, and facing so as to be insulated from the resonator upper portion, A cover plate including a tuning plate including a metal pattern formed to fine-tune the frequency of the resonator is prepared (step S110). Since the cover plate has been described in detail with reference to FIGS. 2 to 5 above, a redundant description thereof will be omitted.

In addition, as a housing including a lower plate and a side wall portion extending upwardly from the lower plate, the housing having at least one resonator lower portion disposed inside the housing is prepared (step S120 ). Since this housing has been described in detail with reference to FIGS. 2 to 5 above, a redundant description thereof will be omitted.

Although it is described above as preparing the housing (step S120) after the cover plate preparation (step S110), the reverse order is also possible, and it will be apparent that it is also possible at the same time.

Then, the cover plate and the housing are coupled so that the upper surface of the lower part of the resonator and the upper surface of the resonator plate are in contact with each other (step S130). In this case, as described above, the upper part of the resonator and the lower part of the resonator may be coupled by solder.

Thereafter, it is determined whether fine tuning is required (step S140), and if fine tuning is required, fine tuning is performed (step S150).

For example, the fine tuning may be performed by pressing the metal pattern of the tuning plate.

FIG. 7 is a partial cross-sectional view illustrating an embodiment of performing the fine tuning shown in FIG. 6 .

2, 3 and 7, when the metal pattern composed of at least one of the lower pattern 141 and the upper pattern 143 is pressed with the pusher P, the metal pattern and the upper part of the resonator 131 are formed. Since the capacitance is changed as the spacing is changed from d1 to d2, the frequency of the resonator can be finely adjusted.

Alternatively, the fine tuning may be performed by removing a portion of the upper pattern 143 .

As described above, in the cavity filter according to the present invention, a cover plate in which capacitance with the resonator element is precisely controlled is attached, so that an additional tuning process using a conventional tuning bolt is not required. That is, in the cavity filter according to the present invention, a tuning process is not required because the overlapping area between the resonant element and the lower surface tuning pattern is precisely controlled for repetitive production of samples.

However, as described above, when fine tuning is required due to a process error, the resonance frequency can be tuned by pressing the metal pattern or removing a part of the upper pattern.

In the foregoing detailed description of the present invention, although it has been described with reference to preferred embodiments of the present invention, those skilled in the art or those having ordinary knowledge in the art will have the spirit of the present invention described in the claims to be described later. And it will be understood that various modifications and variations of the present invention can be made without departing from the technical scope.

100, 200, 300: cavity filter
110. 210: housing 111: lower plate
112: side wall 130, 230: resonator plate
131: upper resonator 132: filling tape
133: resonator substrate 140, 240: tuning plate
141: lower pattern 142: substrate
143: upper pattern 144: lower filling tape
145: upper filling tape 146: via
147: lower shielding portion 148: upper shielding portion
210: resonator 220: cover plate

Claims (12)

a housing including a lower plate and a sidewall portion extending upwardly from the lower plate;
a lower portion of at least one resonator disposed inside the housing; and
a cover plate coupled to the sidewall of the housing to cover the housing;
including,
The cover plate comprises a resonator plate and a tuning plate,
The resonator plate is
resonator substrate; and
an upper portion of the resonator formed on a lower surface of the resonator substrate and forming a resonator in contact with the lower portion of the resonator;
including,
The tuning plate is
Board;
a lower pattern formed on the lower surface of the substrate to face the upper portion of the resonator to be insulated;
an upper pattern formed on the upper surface of the substrate to face the lower pattern; and
a via passing through the substrate and connecting the lower pattern and the upper pattern;
Cavity filter comprising a.
delete According to claim 1,
The resonator plate is
a filling tape attached to a lower surface of the resonator substrate to surround the upper portion of the resonator;
Cavity filter, characterized in that it further comprises.
delete delete delete According to claim 1,
The tuning plate is
an upper filling tape or an upper shielding part attached to the upper surface of the substrate to surround the outer side of the upper pattern;
Cavity filter, characterized in that it further comprises.
According to claim 1,
The tuning plate is
a lower filling tape or lower shielding part attached to the lower surface of the substrate to surround the outer side of the lower pattern;
Cavity filter, characterized in that it further comprises.
A resonator plate including an upper portion of the resonator constituting the resonator in contact with the lower portion of the resonator, and a substrate facing to be insulated from the upper portion of the resonator, a lower pattern formed on the lower surface of the substrate and constituting a metal pattern, on the upper surface of the substrate, preparing a cover plate including a tuning plate including an upper pattern formed to correspond to the lower pattern and a via penetrating through the substrate to connect the lower pattern and the upper pattern;
Preparing a housing comprising a lower plate and a side wall portion extending upwardly from the lower plate, wherein the lower portion of at least one resonator is disposed inside the housing;
coupling the cover plate and the housing so that an upper surface of the lower portion of the resonator and an upper surface of the resonator plate are in contact with each other;
determining whether fine tuning is necessary; and
If fine tuning is required, performing fine tuning;
A method of manufacturing a cavity filter comprising a.
delete delete 10. The method of claim 9,
The fine tuning is
A method of manufacturing a cavity filter, characterized in that it is performed by removing a part of the upper pattern.

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