KR102241217B1 - Ceramic Waveguide Filter and Manufacturing Method Thereof - Google Patents

Abstract

The present invention provides a plurality of resonance cavities defined by a plurality of through partitions formed to divide the partitions of the ceramic block according to a predetermined pattern in a single ceramic block, a metal layer formed on the inner surface of each of the plurality of through partitions, and a plurality of resonance cavities. It provides a ceramic waveguide filter including an input/output interface formed in two resonance cavities for inputting and outputting a medium signal, and a method of manufacturing the same. Therefore, since it can be manufactured integrally with a single ceramic block, it is possible to manufacture at low cost through a simplified manufacturing process, minimize processing errors, and easily tune even when a characteristic change occurs during manufacturing. Also, it is possible to easily generate the transmission zero point.

Description

Ceramic Waveguide Filter and Manufacturing Method Thereof

The present invention relates to a ceramic waveguide filter, and more particularly, to a ceramic waveguide filter used in a mobile communication system.

As the communication service evolves, the data transmission speed increases, and for this, the system bandwidth must also be increased, the reception sensitivity must be improved, and the interference caused by other communication system carriers must be minimized.

To this end, the demand for low insertion loss, high rejection, and filters is increasing day by day. The coaxial resonant cavity manufactured by using a metal material is mainly used to implement a filter in a mobile communication system because it has advantages in terms of loss, size, and cost compared to other resonant cavities such as dielectric resonant cavities.

However, due to the low power and miniaturization of a base station system such as a massive MIMO antenna, there is a limitation in size even when the existing coaxial resonant cavity is used, and the necessity for implementing a very small filter is emerging.

A ceramic waveguide filter is being actively researched as a filter to replace the filter using the existing coaxial resonance cavity. The ceramic waveguide filter is a filter that fills the cavity with a ceramic material having low loss and high dielectric constant, and can significantly reduce the size compared to the existing coaxial resonance cavity filter and provide excellent loss characteristics.

1 is a diagram showing the structure of a conventional ceramic waveguide filter.

Referring to FIG. 1, a conventional ceramic waveguide filter includes a plurality of ceramic cavities 111, 112, 113, and 114, a plurality of partition walls 121, 122, 123, and an input interface port 140 positioned between the cavities. And an output interface port 150.

In the conventional ceramic waveguide filter as shown in FIG. 1, each of the cavities 111, 112, 113, and 114 are independently manufactured as individual ceramic blocks, and partition walls 121, 122, and 123 are formed on one surface of each of the cavities. The partition walls 121, 122, and 123 may be formed through metallization of one surface of the cavity.

Slots 131, 132, and 133 are formed in each of the partition walls for coupling between cavities. The signal of the first cavity 111 can be coupled to the second cavity 112 through the first slot 131 formed in the first partition wall 121.

A conventional conventional ceramic waveguide filter as shown in FIG. 1 requires a process of independently manufacturing each of the ceramic cavities 111, 112, 113, and 114, forming a partition wall, and then combining the respective cavities. The cavities are bonded through soldering or the like.

However, such a cavity bonding process frequently generates misalignment tolerances in the bonding process, and there is a problem in that characteristics change occurs due to such misalignment tolerances. There is a problem in that the yield of the product is remarkably lowered because a large error occurs even by a slight misalignment of bonding.

In addition, if the characteristics change due to processing errors, it is necessary to tune them. However, in the conventional ceramic waveguide filter, tuning is performed by grinding and removing one surface of the ceramic constituting the cavity. Since ceramic is a very hard material, this tuning method requires a high level of technology and it is difficult to fine tune.

In addition, conventional ceramic waveguide filters mainly use cross coupling to provide a transmission-zero point for improving attenuation characteristics. In order to implement cross coupling to the cavities 111, 112, 113, and 114 that are not adjacent to each other in the ceramic waveguide filter of FIG. 1, there is a problem that an additional operation is required.

Korean Registered Patent No. 10-1754278 (registered on 2017.06.29)

The present invention proposes an integrated ceramic waveguide filter that can be manufactured with a simplified manufacturing process and minimized processing errors.

In addition, the present invention proposes a ceramic waveguide filter capable of easy tuning when a characteristic change occurs.

In addition, the present invention proposes a ceramic waveguide filter that can easily implement a transmission zero point by cross coupling.

In order to achieve the above object, the ceramic waveguide filter according to an embodiment of the present invention comprises a plurality of penetrating partitions defined by a plurality of penetrating partitions formed to divide the partitions of the ceramic block according to a predetermined pattern in a single ceramic block. Resonant cavity; A metal layer formed on an inner surface of each of the plurality of through partition walls; And an input/output interface formed in two resonance cavities for inputting and outputting signals among the plurality of resonance cavities. Includes.

The plurality of penetrating barrier ribs may be formed to pass through the ceramic block in a pattern for dividing partitions of the ceramic block so that the plurality of resonance cavities are defined corresponding to a predetermined frequency band, and may be formed to be spaced apart from each other.

The plurality of through partitions are sequentially coupled with adjacent resonant cavities through a coupling window that is a spaced area between the plurality of through partitions in response to a signal input through the input/output interface by the plurality of resonant cavities. A pattern may be formed to filter the frequency band.

The plurality of through partition walls may be formed in a pattern in which at least one of the plurality of resonance cavities is disposed adjacent to the plurality of resonance cavities, so that cross coupling may occur.

In the ceramic waveguide filter, a coupling groove may be further formed between resonance cavities in which the cross coupling occurs on one or the other surface of the ceramic block, and the coupling groove may be spaced apart from the through partition wall between the resonance cavities. Can be formed.

The thickness of the metal layer may be adjusted according to a predetermined frequency band.

In order to achieve the above object, a method of manufacturing a ceramic waveguide filter according to another embodiment of the present invention divides the partitions of the ceramic block according to a predetermined pattern to define a plurality of resonance cavities in a single ceramic block. Forming a plurality of through partition walls; Forming a metal layer on the inner surface of each of the plurality of through partition walls; And forming an input/output interface for inputting and outputting signals to and from two of the plurality of resonance cavities. Includes.

According to an embodiment of the present invention, it is possible to manufacture at low cost through a simplified manufacturing process. In addition, processing errors can be minimized, and tuning can be easily performed even when characteristic changes occur during manufacturing.

1 is a diagram showing the structure of a conventional ceramic waveguide filter.
2 is a diagram showing the structure of a ceramic waveguide filter according to an embodiment of the present invention.
3 shows a result of simulation of the filter characteristics of the ceramic waveguide filter of FIG. 2.
4 is a diagram showing the structure of a ceramic waveguide filter according to another embodiment of the present invention.
5 shows a result of simulation of the filter characteristics of the ceramic waveguide filter of FIG. 4.
6 and 7 respectively show a top view and a perspective view of a ceramic waveguide filter according to another embodiment of the present invention.
8 shows simulation results of filter characteristics of the ceramic waveguide filters of FIGS. 6 and 7.
9 shows a method of manufacturing a ceramic waveguide filter according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and therefore is not limited to the embodiments described herein.

In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected" with another part, this includes not only "directly connected" but also "indirectly connected" with another member interposed therebetween. .

In addition, when a part "includes" a certain component, it means that other components may be further provided, not excluding other components, unless specifically stated to the contrary.

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

2 is a diagram showing the structure of a ceramic waveguide filter according to an embodiment of the present invention, in which (a) shows a top view, and (b) shows a perspective view.

Referring to FIG. 2, in the ceramic waveguide filter according to the present embodiment, a plurality of resonance cavities defined by a plurality of through partition walls 221, 222, 223 penetrating between one surface and the other surface of a single ceramic block 200 ( 211, 212, 213) is implemented as an integral part.

A plurality of through partition walls 221, 222, 223 are formed to penetrate through the ceramic block 200 according to a predetermined pattern to divide the division of the ceramic block 200 to define a plurality of resonance cavities 211, 212, 213 do. In FIG. 2, as an example, a plurality of through partition walls 221, 222, 223 are shown to be formed in a pattern extending in a straight line in the lateral direction from the ceramic block 200, but the present embodiment is not limited thereto. In this embodiment, the plurality of through partition walls 221, 222, 223 may be formed in various shapes that can easily divide the division of the ceramic block 200, and in some cases, such as a T-shape or a Y-shape. It may also be formed in the form of a branch pattern.

However, in this embodiment, a plurality of through partition walls 221, 222, 223 are formed to be spaced apart from each other. At this time, at least one of the plurality of through partition walls 221, 222, 223 may be formed to extend to a side boundary of the ceramic block 200. Since a plurality of through partitions 221, 222, 223 are formed to be spaced apart from each other, even if all the through partitions 221, 222, 223 are formed to extend to the side boundary of the ceramic block 200, the ceramic block 200 is It can maintain the shape of a single structure without being cut.

In addition, metal layers 231, 232, and 233 are formed on the inner surfaces of the plurality of through partition walls 221, 222, and 223. The metal layers 231, 232, and 233 may be formed by applying a metallization process such as plating, deposition, and sputtering. Typically, in RF equipment such as filters and waveguides, silver (Ag) having excellent electrical conductivity is used among conductive materials to minimize loss, but conductive materials other than silver may be used to improve properties such as corrosion resistance.

In this embodiment, a plurality of resonance cavities 211, 212, 213 divided by a plurality of through partition walls 221, 222, 223 are a plurality of ceramic cavities 111, in the conventional ceramic wave guide filter shown in FIG. 112, 113, 114).

Since a number of resonant cavities 211, 212, 213 are divided and defined by a number of through bulkheads 221, 222, 223, a number of through bulkheads 221, 222, 223 function as cavity walls. In addition, the space between the plurality of through partition walls 221, 222, 223 may be viewed as a coupling window forming a coupling surface between the plurality of resonance cavities 211, 212, and 213.

As the plurality of through partition walls 221, 222, and 223 are formed to be spaced apart from each other, the resonant cavities adjacent to each other among the plurality of resonance cavities 211, 212, and 213 are formed in the through partition walls 221, 222, 223 in the ceramic block 200. ) May be resonated through a coupling window, which is a region in which the) is not formed, and thus coupling may be achieved. To this end, the patterns of the plurality of through partition walls 221, 222, 223 may be formed in a form in which a plurality of resonance cavities 211, 212, 213 can be easily coupled. In addition, the pattern of the plurality of through partition walls 221, 222, 223 may be adjusted so that the plurality of resonance cavities 211, 212, 213 resonate in a designated frequency band, that is, the size of the resonance cavity is determined. In FIG. 2, as an example, a pattern of a plurality of through partition walls 221, 222, 223 is illustrated in a case in which a plurality of resonance cavities 211, 212, 213 are formed to resonate in the TE101 mode.

In this embodiment, the input/output interfaces 240 and 250 are provided in the two resonance cavities 211 and 213 of the initial stage and the last stage according to the specified coupling order among the plurality of resonance cavities 211, 212, 213 of the ceramic waveguide filter in this embodiment. ) Is formed. In addition, an input/output interface port for inputting and outputting signals through a ceramic waveguide filter may be inserted into the formed input/output interfaces 240 and 250. Here, the input/output interfaces 240 and 250 may be formed as through holes penetrating between one surface and the other surface of the ceramic block 200, for example.

In FIG. 2, as an example, the input/output interfaces 240 and 250 are illustrated as being formed in the first and third resonance cavities 211 and 213. In this case, it is assumed that the input interface port is inserted into the input/output interface 240 formed in the first resonance cavity 211. In this case, the first resonance cavity 211 receives a signal from the input interface inserted in the input/output interface 240, and the adjacent first resonance cavity 211 through a coupling window that is a space between the first through partition walls 221 ) And the second resonant cavity 212 is coupled to each other. Further, coupling is made between the adjacent second resonance cavity 212 and the third resonance cavity 213 through a coupling window, which is a space between the second through partition walls 222, and the third resonance cavity 213 is input/output. A signal is output to an output interface port passing through the interface 250.

At this time, each of the plurality of resonance cavities 211, 212, and 213 may resonate in a frequency band designated according to the size and shape defined by the plurality of through partition walls 221, 222, and 223. Therefore, in the ceramic waveguide filter according to the present embodiment, a plurality of resonance cavities 211, 212, 213 defined by a plurality of through barrier ribs 221, 222, 223 filter signals transmitted through the input interface port in multiple stages. Output can be output through the interface port. That is, in the ceramic waveguide filter according to the present embodiment, the first to third resonance cavities 211, 212, 213 sequentially filter the signal input from the input interface, similar to the conventional ceramic waveguide filter of FIG. 1. Can be output to the output interface.

On the other hand, when coupling is sequentially performed in the plurality of resonance cavities 211, 212, 213 as in the ceramic waveguide filter of FIG. 1, the plurality of through partition walls 221, 222, and 223 are formed from the ceramic block 200 to the side. It may be formed in a pattern extending parallel to each other. However, in this case, it is difficult to implement cross-coupling between the plurality of resonant cavities 211, 212, and 213.

On the other hand, in the ceramic waveguide filter according to the present embodiment illustrated in FIG. 2, a plurality of through partition walls 221 are provided so that the first resonance cavity 211 is also adjacent to the second resonance cavity 212 and the third resonance cavity 213. 222 and 223 were formed in patterns extending in different directions from the center of the ceramic block 200 to the side. This is to facilitate cross-coupling in the ceramic waveguide filter according to the present embodiment.

As described above, when the order of the first resonance cavity 211, the second resonance cavity 212, and the third resonance cavity 213 is the coupling path, the first resonance cavity 211 and the first resonance cavity 211 and the second resonance cavity 211 2 Coupling is made between the resonant cavities 212. In addition, cross coupling may be formed between the first resonance cavity 211 and the third resonance cavity 213. That is, as the plurality of through partition walls 221, 222, 223 are formed so that the first resonance cavity 211 is disposed adjacent to not only the second resonance cavity 212 but also the third resonance cavity 213, the first resonance cavity Cross coupling between the 211 and the third resonant cavity 213 may be easily performed.

Cross-coupling between the first resonance cavity 211 and the third resonance cavity 213 generates a transmission-zero point, thereby improving attenuation characteristics of the ceramic waveguide filter. That is, the ceramic waveguide filter according to the present embodiment easily generates a transmission-zero point by implementing cross coupling without additional work according to the formation pattern of the plurality of through partition walls 221, 222, 223. I can make it.

In some cases, in order to suppress cross-coupling between the first resonance cavity 211 and the third resonance cavity 213, the third through partition wall 223 may be formed to extend to the side of the ceramic block 200. have.

As described above, in the case of a conventional ceramic waveguide filter, a plurality of cavities 111, 112, 113, and 114 each made of a ceramic block are bonded to each other, whereas the ceramic waveguide filter according to the present embodiment is a single filter. A plurality of resonant cavities 211, 212, 213 are formed in the ceramic block 200 by a plurality of through partition walls 221, 222, 223, and are manufactured integrally. Accordingly, a cavity coupling process for joining a plurality of cavities 111, 112, 113, and 114 is omitted. Accordingly, it is possible to easily manufacture by simplifying the manufacturing process, and it is possible to prevent the occurrence of characteristic variation due to misalignment tolerance.

Meanwhile, a ceramic waveguide filter made of ceramic material reacts sensitively to mechanical tolerances. Therefore, tuning is essential to ensure that the ceramic waveguide filter performs accurate filtering.

As shown in FIG. 1, for accurate tuning of the conventional ceramic waveguide filter to which a plurality of cavities 111, 112, 113, and 114 are bonded, characteristics in a state in which a plurality of cavities 111, 112, 113, and 114 are combined. Should be checked. Then, tuning is performed so that the identified characteristics are adjusted to the required characteristics. At this time, in the conventional ceramic waveguide filter, since a plurality of cavities 111, 112, 113, and 114 are already bonded, grinding the surfaces of a plurality of cavities 111, 112, 113, and 114 made of ceramic It is done in a way that modulates its properties. However, there is a problem that the ceramic material is very hard and is not easy to process.

In contrast, in the ceramic waveguide filter according to the present embodiment, since a metal layer made of a material softer than a ceramic material is formed on the inner surfaces of the plurality of through partition walls 221, 222, 223, the thickness can be easily adjusted by grinding the metal layer. . That is, it is possible to easily perform a tuning operation to adjust the characteristics of the ceramic waveguide filter.

In the above description, as an example, the tuning operation is performed by grinding the metal layer, but various methods for adjusting the thickness of the metal layer may be used for the tuning operation.

In addition, in FIG. 2, as an example, the ceramic block 200 is shown to be implemented as a rectangular parallelepiped, but is not limited thereto and may be implemented in various forms to improve the performance of the ceramic waveguide filter. In addition, the size of the ceramic block 200 may also vary in various ways according to the frequency band of the signal to be filtered.

3 shows a result of simulation of the filter characteristics of the ceramic waveguide filter of FIG. 2.

Referring to FIG. 3, a ceramic waveguide filter including three resonance cavities 211, 212, and 213 shown in FIG. 2 operates as a band pass filter (BPF). In particular, it can be seen that since the first resonance cavity 211 and the third resonance cavity 213 are inductively cross-coupled, the ceramic waveguide filter can generate a transmission zero point at a frequency of 3.6 GHz, which is a higher frequency than the transmission band. .

4 is a diagram showing the structure of a ceramic waveguide filter according to another embodiment of the present invention.

The ceramic waveguide filter shown in FIG. 4 basically has the same configuration as the ceramic waveguide filter of FIG. 2. Therefore, in the ceramic waveguide filter of FIG. 4, the same identification number is assigned to the same configuration as that of the ceramic waveguide filter of FIG.

However, compared to the ceramic waveguide filter of FIG. 2, the ceramic waveguide filter of FIG. 4 has a third through partition wall between the first resonance cavity 211 and the third resonance cavity 213 on one or the other side of the ceramic block 200. In addition to 223, a coupling groove 360 is further formed.

Here, the coupling groove 360 cannot be formed to overlap the third through partition wall 223. Therefore, when the coupling groove 360 is formed, the length of the third through partition wall 223 may be adjusted so that the corresponding third through partition wall 223 does not overlap with the position of the coupling groove 360. As an example, the length of the third through partition wall 223 of FIG. 4 is shorter than that of the third through partition wall 223 compared to FIG. 2.

In the ceramic waveguide filter of FIG. 2, a plurality of resonant cavities 211, 212, 213 may be subjected to inductive cross coupling in which an H-field predominates. On the other hand, in the ceramic waveguide filter of FIG. 4, as the coupling groove 360 is further formed between the first resonance cavity 211 and the third resonance cavity 213, the first resonance cavity 211 and the third resonance Between the cavities 213, capacitive cross coupling is performed in which an electric field (E-field) predominates.

As shown in FIG. 4, a coupling groove 360 is further formed between the first resonance cavity 211 and the third resonance cavity 213, so that the first resonance cavity 211 and the third resonance cavity 213 When capacitive cross-coupling is mainly performed therebetween, the frequency at which the transmission zero is generated varies, and thus, the filter characteristics of the ceramic waveguide filter may be varied.

5 shows a result of simulation of filter characteristics of the ceramic waveguide filter of FIG. 4.

Comparing the simulation result of FIG. 5 with FIG. 3, in the simulation result shown in FIG. 5, the coupling groove ( 360) is formed to form a capacitive cross-coupling between the first resonance cavity 211 and the third resonance cavity 213, so that the ceramic waveguide filter has a transmission zero point at a frequency of 3.3 GHz, which is lower than the passband. It can be confirmed that it can occur.

That is, the ceramic waveguide filter according to the present exemplary embodiment may change the frequency at which the transmission zero is generated depending on whether a coupling groove is additionally formed between two resonant cavities in which cross coupling occurs.

In FIGS. 2 and 4, as a simple example for convenience of description, a ceramic waveguide in which three resonance cavities 211, 212, and 213 are formed by three through partition walls 221, 222, 223 on the ceramic block 200 Although a filter is shown, the present invention is not limited thereto.

6 and 7 respectively show a top view and a perspective view of a ceramic waveguide filter according to another embodiment of the present invention.

In the ceramic waveguide filter according to the present invention, a plurality of resonance cavities may be defined by a plurality of through partitions formed through the ceramic block 400 according to a predetermined pattern. Accordingly, in FIGS. 6 and 7, six penetrating partition walls 621 to 626 penetrating between one surface and the other surface of the ceramic block 600 are formed according to a predetermined pattern to divide the ceramic block 600 into six partitions, Six resonant cavities 611 to 616 are defined.

The six through partition walls 621 to 626 are formed in a pattern for dividing the ceramic block 600 into six partitions, and the shape of the six through partition walls 621 to 626 may be formed differently. In addition, as shown in FIGS. 6 and 7, the six through partition walls 621 to 626 may be formed in different patterns, and some may be formed in a branch pattern shape such as a T-shape or a Y-shape. have.

Metal layers 631 to 636 are formed on the inner surfaces of each of the six through partition walls 621 to 626.

In addition, input/output interfaces 640 and 650 into which input/output interface ports are inserted are formed in the first resonance cavity 611 and the sixth resonance cavity 616 among the six resonance cavities 611 to 616. The first resonance cavity 611 receives a signal from the input interface port inserted in the input/output interface 640, and is sequentially coupled in the second to sixth resonance cavities 612 to 616, and the sixth resonance cavity 616 outputs a signal to an output interface port inserted in the input/output interface 650.

The first to sixth resonance cavities 611 to 616 may be sequentially coupled through a coupling window between the six through partition walls 621 to 626 formed to be spaced apart. That is, coupling is made between the first resonance cavity 611 and the second resonance cavity 612 through the coupling window corresponding to the first and second penetration partition walls 621 and 622, and the second and third penetrations A coupling is made between the second resonance cavity 612 and the third resonance cavity 613 through a coupling window corresponding to the partition walls 622 and 623, and the third and fourth penetration partition walls 623 and 624 A coupling may be made between the third resonance cavity 613 and the fourth resonance cavity 614 through a corresponding coupling window. And coupling is made between the fourth and fifth resonance cavity 614 and the fifth resonance cavity 615 through a coupling window corresponding to the fourth and fifth through partition walls 624 and 625, and the fifth and sixth penetration A coupling may be formed between the fifth and sixth resonance cavities 615 and 616 through coupling windows corresponding to the partition walls 625 and 626.

At this time, the first to sixth resonant cavities 611 to 616 resonate in a designated frequency band to filter a signal in a designated frequency band. Therefore, the ceramic waveguide filter shown in FIGS. 6 and 7 functions as a multi-stage filter that performs six-stage filtering.

Meanwhile, in the ceramic waveguide filter shown in FIGS. 6 and 7, cross coupling between the first resonance cavity 611 and the third resonance cavity 613 through a coupling window corresponding to the second through partition wall 622 This can be done easily. In addition, cross-coupling may be made between the second resonant cavity 612 and the adjacent fourth resonant cavity 614, and cross-coupling between the third resonant cavity 613 and the fifth resonant cavity 615 is also possible. The fourth resonance cavity 614 and the sixth resonance cavity 616 may be cross-coupled. That is, in the ceramic waveguide filter illustrated in FIGS. 6 and 7, cross coupling may occur between a plurality of resonant cavities.

However, at least one of the six through partitions 621 to 626 may be formed to extend to a side boundary of the ceramic block 600 so that cross coupling between the resonance cavities is suppressed. For example, in the ceramic waveguide filter of FIGS. 6 and 7, cross coupling between the second and fourth resonance cavities 612 and 614, and the fourth and sixth resonance cavities 614 and 616 In order to suppress this, each of the third through partition wall 623 and the fifth through partition wall 625 may be formed to extend to a side boundary of the ceramic block 600.

In addition, in FIGS. 6 and 7, a coupling groove 660 is further formed with a second through partition wall 622 between the first and third resonance cavities 611 and 613 to form the first and third resonance cavities 611, 613) Capacitive cross-coupling can be achieved. In this case, the pattern of the second through partition wall 622 may be adjusted so as not to overlap with the region where the coupling groove 660 is formed.

As a result, referring to FIGS. 6 and 7, in the ceramic waveguide filter according to the present exemplary embodiment, a plurality of through partition walls 621 to 626 are formed in a single ceramic block, so that a plurality of resonance cavities can be easily implemented.

8 shows simulation results of filter characteristics of the ceramic waveguide filters of FIGS. 6 and 7.

In FIG. 8, a coupling groove 660 is formed between the first and third resonance cavities 611 and 613 in the ceramic waveguide filter of FIGS. 6 and 7, and the third and fifth through partition walls 623 and 625 Is extended to the side boundary of the ceramic block 600 to suppress cross-coupling between the second resonance cavity 612 and the fourth resonance cavity 614 and the fourth resonance cavity 614 and the sixth resonance cavity 616 Is assumed.

As the coupling groove 660 is formed between the first and third resonant cavities 611 and 613, a capacitive cross coupling is formed between the first resonant cavity 611 and the third resonant cavity 613. On the other hand, inductive cross-coupling is performed between the third resonant cavity 613 and the fifth resonant cavity 615.

3 and 5, inductive cross-coupling generates a transmission zero at a frequency higher than a transmission band, whereas capacitive cross-coupling generates a transmission zero at a frequency lower than a transmission band.

Accordingly, it can be seen that the ceramic waveguide filters of FIGS. 6 and 7 in which both inductive cross-coupling and capacitive cross-coupling are generated have transmission zeros at both ends of the transmission band frequency, as shown in FIG. 8. . And these results indicate that the ceramic waveguide filter according to the present exemplary embodiment can function as a band pass filter with very good performance.

9 shows a method of manufacturing a ceramic waveguide filter according to an embodiment of the present invention.

A method of manufacturing the ceramic waveguide filter of FIG. 9 will be described with reference to FIGS. 2 to 8.

Prior to manufacturing the ceramic waveguide filter, the frequency band and filtering characteristics to be filtered by the ceramic waveguide filter are predetermined. Then, a ceramic block is manufactured according to the determined frequency band (S10). Here, the ceramic block may be manufactured by having a size and shape determined according to the determined frequency band.

In addition, a plurality of penetrating partitions penetrating one side and the other side of the ceramic block are formed in a predetermined pattern according to the frequency band to be filtered, thereby dividing the ceramic block into a plurality of sections, thereby implementing a plurality of resonance cavities (S20). At this time, a plurality of through partition walls are formed to be spaced apart from each other. Since a plurality of through partition walls are formed to be spaced apart from each other, a plurality of resonance cavities may be coupled through a spaced coupling window between the plurality of through partition walls.

When a plurality of through-barriers are formed, a metal layer is formed by applying a metallization process such as plating, deposition, and sputtering with a conductive material such as silver on the inner surfaces of each of the plurality of through-barriers (S30).

In addition, input/output interfaces are formed in two of the plurality of resonance cavities (S40). Here, the input/output interface is at both ends in a sequence in which a plurality of resonance cavities of the ceramic waveguide filter receive signals from the input interface port and are sequentially coupled, so that the filtered signal can be output to the output interface port. It can be formed in the resonance cavity of.

On the other hand, if capacitive cross-coupling is required according to the determined filtering characteristics, that is, if a transmission zero point is to be generated at a frequency lower than the passband, a coupling groove for generating capacitive cross-coupling is further formed ( S50). Here, the step of forming the coupling groove may be omitted when capacitive cross coupling is not required.

In addition, the characteristics of the ceramic waveguide filter are tuned by finely adjusting the coupling value between the plurality of resonance cavities by adjusting the thickness of the metal layer formed on the inner surface of each of the plurality of through partitions, such as grinding (S60).

In the method of manufacturing a ceramic waveguide filter of FIG. 9, the steps of forming a metal layer (S30), forming an input/output interface (S40), and further forming a coupling groove (S50) are in sequence to improve process efficiency. Can be adjusted.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those of ordinary skill in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

111, 112, 113, 114: ceramic cavity
121, 122, 123: bulkhead
131, 132, 133: slot
140: input interface port
150: output interface port
200: ceramic block
211, 212, 213: resonance cavity
221, 222, 223: penetrating bulkhead
231, 232, 233: metal layer
240, 250: input/output interface
360: coupling groove

Claims (12)

A plurality of resonance cavities defined by a plurality of through partitions formed to divide the partitions of the ceramic block in a single ceramic block according to a predetermined pattern;
A metal layer formed on an inner surface of each of the plurality of through partition walls; And
An input/output interface formed in two resonance cavities for inputting and outputting signals among the plurality of resonance cavities; Including,
The plurality of through bulkheads
A pattern that divides the ceramic block so that the plurality of resonant cavities are defined in correspondence with a predetermined frequency band, is formed through the ceramic block, and is formed to be spaced apart from each other,
At least one of the plurality of resonance cavities is formed in a pattern disposed adjacent to the plurality of resonance cavities, so that cross coupling occurs,
A coupling groove is further formed between the resonant cavity in which the cross coupling occurs on one or the other surface of the ceramic block,
The coupling groove is formed to be spaced apart from the through partition wall between the resonance cavity.

delete The method of claim 1, wherein the plurality of through partitions are
Filtering the frequency band while the plurality of resonance cavities are sequentially coupled with adjacent resonance cavities through a coupling window spaced apart between the plurality of through partitions in response to a signal input through the input/output interface Ceramic waveguide filter with a patterned pattern.
delete delete The method of claim 1, wherein the metal layer
Ceramic waveguide filter whose thickness is adjusted according to a predetermined frequency band. Forming a plurality of penetrating partitions for dividing partitions of the ceramic block according to a predetermined pattern to define a plurality of resonance cavities in a single ceramic block;
Forming a metal layer on the inner surface of each of the plurality of through partition walls; And
Forming an input/output interface for inputting and outputting signals to and from two of the plurality of resonance cavities; Including,
The step of forming the plurality of through partition walls
Dividing the partitions of the ceramic block so that the plurality of resonance cavities are defined corresponding to a predetermined frequency band, and penetrating the ceramic block in a pattern spaced apart from each other to form the plurality of through partition walls,
The step of forming the plurality of through partition walls
At least one of the plurality of resonance cavities is formed in a pattern disposed adjacent to the plurality of resonance cavities, so that cross coupling occurs,
Forming a coupling groove spaced apart from a through partition wall between resonant cavities in which the cross coupling occurs on one or the other surface of the ceramic block; The method of manufacturing a ceramic waveguide filter further comprising a.
delete The method of claim 7, wherein the forming of the plurality of through partitions comprises:
In response to a signal input through the input/output interface, the plurality of resonance cavities are sequentially coupled with adjacent resonance cavities through a coupling window spaced apart between the plurality of through partitions, and the frequency band is filtered. A method of manufacturing a ceramic waveguide filter in which a pattern is formed so as to be performed.

delete delete The method of claim 7, wherein the method of manufacturing the ceramic waveguide filter
Adjusting the thickness of the metal layer according to a predetermined frequency band; The method of manufacturing a ceramic waveguide filter further comprising a.

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