WO2023038265A1 - Small ceramic waveguide filter - Google Patents

Abstract

The present invention provides a small ceramic waveguide filter which can be manufactured in a very small size and can also be reduced in weight, the filter comprising: a plurality of resonant cavities defined as compartments divided by a plurality of through partition walls formed passing through a single ceramic block according to a predetermined pattern; a plurality of resonant grooves which are formed in an inward direction from one surface of the ceramic block in each of the compartments of the plurality of resonant cavities divided by the through partition walls, wherein the diameter of the resonant grooves is smaller toward the one surface of the ceramic block than at the inner end of the ceramic block; and a metal layer formed on the outer surface of the ceramic block and the inner surface of each of the plurality of resonant grooves.

Description

Miniature Ceramic Waveguide Filter

The present invention relates to a ceramic waveguide filter, and relates to a low-loss, high-suppression miniature ceramic waveguide filter.

As the communication service evolves, the data transmission speed increases, and for this, the system bandwidth must also increase, and it is necessary to improve reception sensitivity and minimize interference caused by carriers of other communication systems.

To this end, we are facing a situation in which the demand for low insertion loss, high rejection, and filters is increasing day by day. Coaxial resonant cavities manufactured using metal materials have advantages in terms of loss, size, and price compared to other resonant cavities such as dielectric resonant cavities, so they are mainly used to implement filters in mobile communication systems.

However, due to the low power and miniaturization of a base station system such as a massive MIMO antenna, there are limitations in terms of size even when using an existing coaxial resonance cavity, and the need for implementing a subminiature filter is emerging.

For this reason, research on a ceramic waveguide filter is being actively conducted as a filter to replace a filter using an existing coaxial resonance cavity. A ceramic waveguide filter is a filter that fills a cavity with a ceramic material having low loss and high permittivity, and can significantly reduce the size compared to conventional coaxial resonance cavity filters and provide excellent loss characteristics.

Conventional general ceramic waveguide filters require a process of independently manufacturing each ceramic cavity, forming a barrier rib, and then combining the respective cavities. The bonding of the cavities is accomplished through soldering or the like.

However, the cavity bonding process has a problem in that misalignment tolerance frequently occurs during the bonding process, which causes a change in characteristics and significantly lowers the yield of the product. In addition, when the characteristics are changed due to processing errors, a tuning process by grinding one side of the ceramic is required. However, since ceramic is a very hard material, it requires a high degree of skill and has a problem in that fine tuning is difficult. In addition, in the case of providing a transmission-zero to improve the attenuation characteristics of a ceramic waveguide filter, cross coupling is mainly used, but cross coupling between cavities that are not adjacent to each other In order to implement the ring, there was a problem that additional work was required.

To solve this problem, an integral ceramic waveguide filter implemented as a single ceramic block has been proposed.

1 shows an example of a conventional integrated ceramic waveguide filter, and FIG. 2 shows a cross-sectional side view of the ceramic waveguide filter of FIG. 1 .

Referring to FIGS. 1 and 2 , the integrated ceramic waveguide filter 10 includes a plurality of penetrating barrier ribs formed to penetrate between one surface and the other surface of a single ceramic block 10a and divide the ceramic block according to a predetermined pattern ( 21 and 22) includes a plurality of resonant cavities 11 to 16 defined by.

The plurality of through partition walls 21 and 22 function as a cavity wall that divides the plurality of resonance cavities 11 to 16, and among the plurality of through partition walls 21 and 22, a plurality of through partition walls formed to be spaced apart from each other. The space between may function as a coupling window forming a coupling surface between the plurality of resonance cavities 11 to 16 .

Resonance grooves 31 to 36 may be formed on one surface or the other surface of the ceramic block 10a in each of the plurality of resonance cavities 11 to 16 . Each of the plurality of resonance grooves 31 to 36 is formed at the center where the electric field is concentrated in the region of the corresponding resonance cavity 11 to 16 to increase the resonant frequency by increasing the capacitive component of each of the plurality of resonance cavities 11 to 16. causes a lowering effect. Therefore, the ceramic waveguide filter could be miniaturized by reducing the size of each of the resonance cavities 11 to 16.

In this case, an inductive coupling in which a magnetic field (H-field) acts predominantly may be formed between the resonant cavities 11 to 16 formed adjacent to each other. On the other hand, capacitive coupling is not easily achieved because the electric field (E-field) transverses at the coupling window surface between the plurality of through- partition walls 21 and 22 formed apart from each other. .

As shown in FIG. 2, a ceramic block 10a is formed so that a capacitive coupling in which an E-field predominantly acts between the resonant cavities 11 to 16 formed adjacent to each other. Coupling grooves 40 formed deeper than the resonance grooves 31 to 36 may be further formed on one side or the other side.

1 shows an integrated ceramic waveguide filter in which six resonant cavities 11 to 16 are formed, for example. However, since 32 or 64 ceramic waveguide filters must be mounted in recent massive MIMO devices, there is still a demand for size and weight reduction even when an integrated ceramic waveguide filter as shown in FIG. 1 is used.

An object of the present invention is to provide a ceramic waveguide filter that can be manufactured in a small size.

In order to achieve the above object, a small ceramic waveguide filter according to an embodiment of the present invention includes a plurality of resonant cavities defined as sections divided by a plurality of penetrating partition walls formed by penetrating a single ceramic block according to a predetermined pattern; Formed in an inward direction from one surface of the ceramic block within each of the plurality of resonant cavities partitioned by the through partition wall, the diameter at the one surface side of the ceramic block is formed smaller than the diameter at the inner end of the ceramic block multiple resonant grooves; and a metal layer formed on an outer surface of the ceramic block and an inner surface of each of the plurality of resonance grooves.

Each of the plurality of resonance grooves is formed in a cylindrical shape extending from one surface side of the ceramic block to a predetermined depth with a predetermined first diameter, and is formed at a terminal end with a predetermined second diameter longer than the first diameter, so that the side cross-section It may have this T-shaped structure.

The ceramic waveguide filter is formed in an inward direction from one surface of the ceramic block between at least two adjacent resonance cavities among the plurality of resonance cavities, and the diameter at the one surface side of the ceramic block is the diameter at the inner end of the ceramic block. It is smaller and may further include at least one coupling groove in which the metal layer is formed on an inner surface.

The at least one coupling groove is formed in a cylindrical shape extending from one surface side of the ceramic block to a predetermined depth with a predetermined third diameter, and is formed at a terminal end with a predetermined fourth diameter longer than the third diameter. The cross section may have a T-shaped structure.

The ceramic waveguide filter is formed to pass through the ceramic block between at least two adjacent resonance cavities among the plurality of resonance cavities, and the diameter of the through hole penetrating the ceramic block is equal to or greater than that of an inlet area on one side of the ceramic block. It is smaller than the diameter and may further include at least one coupling hole in which the metal layer is formed on an inner surface.

In order to achieve the above object, a method of manufacturing a small ceramic waveguide filter according to another embodiment of the present invention includes forming a plurality of penetration barriers penetrating a single ceramic block according to a predetermined pattern to define a plurality of resonance cavities; A plurality of resonant cavities extending inwardly from one surface of the ceramic block within each of the plurality of resonant cavities partitioned by the through-partition wall, the diameter at one surface of the ceramic block being smaller than the diameter at the inner end of the ceramic block. Forming a resonance groove; and forming a metal layer on an outer surface of the ceramic block and an inner surface of each of the plurality of resonance grooves.

Therefore, in a small ceramic waveguide filter according to an embodiment of the present invention, in each of a plurality of resonance cavities defined by a plurality of through-barriers in a single ceramic block, a resonance groove formed in an inward direction from one surface of the ceramic block is formed on one surface of the ceramic block. It is formed in a step structure with a larger diameter at the inner end to increase capacitance, so that it can be manufactured in a very small size compared to the existing integrated ceramic waveguide filter, and the weight can also be reduced. In addition, similar to the resonance groove, a coupling groove having a stepped structure may be formed between the resonance grooves to be used as a capacitive reactance for capacitive coupling, so that it can be manufactured in a smaller size.

1 shows an example of a conventional integral ceramic waveguide filter.

FIG. 2 shows a cross-sectional side view of the ceramic waveguide filter of FIG. 1 .

3 to 6 are views for explaining an integrated ceramic waveguide filter according to a first embodiment of the present invention.

7 to 10 are views for explaining an integrated ceramic waveguide filter according to a second embodiment of the present invention.

11 to 14 are views for explaining an integral ceramic waveguide filter according to a third embodiment of the present invention.

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

In order to fully understand the present invention and its operational advantages and objectives achieved by the practice of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the described embodiments. And, in order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals in the drawings indicate the same members.

Throughout the specification, when a part "includes" a certain component, it means that it may further include other components, not excluding other components unless otherwise stated. In addition, terms such as "... unit", "... unit", "module", and "block" described in the specification mean a unit that processes at least one function or operation, which is hardware, software, or hardware. And it can be implemented as a combination of software.

3 to 6 are views for explaining an integrated ceramic waveguide filter according to a first embodiment of the present invention.

FIG. 3 shows an upper perspective view of the integrated ceramic waveguide filter 100 according to this embodiment, FIG. 4 shows a lower perspective view, and FIG. 5 shows a projected plan view. And Figure 6 shows a side cross-sectional view. Here, FIG. 6 shows a cross-sectional view of the ceramic waveguide filter 100 taken along line A - A' of FIG. 5 .

3 to 6, the integrated ceramic waveguide filter 100 according to the present embodiment also penetrates between one surface and the other surface of a single ceramic block 100a like the ceramic waveguide filter of FIG. 1 in a predetermined pattern. It is integrally implemented including a plurality of resonant cavities 111 to 116 defined by a plurality of formed through partition walls 121 and 122 . Each of the resonant cavities 111 to 116 partitioned by a plurality of through- partition walls 121 and 122 can be regarded as a configuration corresponding to an individual resonator in a conventional ceramic waveguide filter.

Among the two through partition walls 121 and 122, the first through partition wall 121 is formed in a T-pattern to resonate with the first and sixth resonance cavities 111 and 116 and the second and fifth resonance in the ceramic block 100a. Sections of the cavities 112 and 115 are divided, and sections of the first and sixth resonant cavities 111 and 116 are divided from each other. Also, the second through partition 122 is formed in a straight pattern to divide the second and fifth resonance cavities 112 and 115 and the third and fourth resonance cavities 113 and 114 in the ceramic block 100a. .

That is, the penetrating barrier ribs 121 and 122 are formed to penetrate between one surface and the other surface of the ceramic block 100a according to a predetermined pattern and function as a cavity wall dividing the ceramic block 100a into compartments, thereby providing a plurality of Resonant cavities 111 to 116 are defined.

Here, as an example, a case in which six resonance cavities 111 to 116 are formed by two through partition walls 121 and 122 and six resonance grooves 131 to 136 formed in a single ceramic block 100a is shown, but the through partition wall It is apparent to those skilled in the art that the number of and the number of resonant cavities can be increased or decreased as needed.

Also, as an example, the two through partition walls 121 and 122 are illustrated as being formed in a T-shaped pattern and a straight line pattern, but the present invention is not limited thereto. In the present embodiment, the plurality of through barrier ribs may be formed in various shapes to easily distinguish partitions of the plurality of resonance cavities according to the number and arrangement structure of the plurality of resonance cavities to be formed in the ceramic block 100a. The penetrating barrier rib may be formed in a Y-shaped or +-shaped branching pattern, or may be formed in a plurality of rectilinear shapes spaced apart from each other. In FIG. 1 , the first penetration barrier 121 may be formed in a +-shaped pattern instead of a T-shaped pattern, and the T-shaped pattern or the +-shaped pattern may be formed by dividing two or three straight line patterns spaced apart from each other. . In addition, the second through partition 122 may also be formed by being divided into two straight line patterns spaced apart from each other, or may be formed in a T-shaped pattern additionally extending in the direction of the coupling groove 140 . Additionally, at least one of the plurality of through partition walls 121 and 122 may be formed up to the side boundary of the ceramic block 100a.

However, the through partition walls 121 and 122 are spaced apart from each other or are formed so as not to reach the side boundary of the ceramic block 100a, so that a couple between adjacent resonance cavities that are not completely divided by the through partition walls 121 and 122 is formed. ring can be made. That is, among the plurality of resonant cavities 111 to 116, areas not divided by the through partition walls 121 and 122 between adjacent resonant cavities function as a coupling window forming a coupling surface between the resonant cavities, thereby generating adjacent resonant cavities. Coupling may be made between cavities.

Here, a through partition wall is provided to facilitate coupling between the third resonant cavity 113 and the fourth resonant cavity 113 and 114 and cross coupling between the second resonant cavity 112 and the fifth resonant cavity 115. Although a case in which this is not formed is illustrated, a through partition wall may be formed.

Meanwhile, in the ceramic waveguide filter 100 according to the present embodiment, resonant grooves 131 to 136 are formed in an inward direction from one surface of the single ceramic block 100a at predetermined positions of each of the plurality of resonant cavities 111 to 116. It can be.

As shown in FIGS. 1 and 2 , the existing resonant grooves 31 to 36 are formed in a cylindrical shape having a uniform diameter or gradually decreasing in diameter while progressing from one surface of the ceramic block 10a to the inside. In contrast, each of the plurality of resonance grooves 131 to 136 according to the present embodiment is formed in a cylindrical shape in an inward direction from one surface of the ceramic block 100a, and the diameter r2 at the inner end is the diameter r1 at the one surface. ) is formed as a step structure that expands more rapidly or gradually. That is, as shown in FIG. 6 , each of the plurality of resonance grooves 131 to 136 has a first diameter r1 on one side of the ceramic block 100a and is formed in a cylindrical shape extending to a predetermined depth. (133a, 134a) and the end portion (133b, 134b) having a second diameter (r2) longer than the first diameter (r1), the cross section is formed to have a T-shaped structure as a whole.

In each of the plurality of resonance grooves 131 to 136, a step impedance structure is applied in which the end portions 133b and 134b having a larger diameter r2 have a larger impedance than the inlet portions 133a and 134a. can be seen as In the plurality of resonant grooves 131 to 136 to which such a step impedance structure is applied, the capacitance at the end portions 133b and 134b is greatly increased, so that the existing resonant grooves 31 to 36 having a similar first diameter r1 Compared to this, an effect of further lowering the resonant frequency may be generated. Therefore, compared to the conventional ceramic waveguide filter 10 shown in FIG. 1, each resonator is implemented to have the same capacitance even with a smaller size, so that the size of the ceramic waveguide filter 100 can be further miniaturized. .

A metal layer 100b is formed on the outer surface of the ceramic block 100a. The metal layer 100b may be formed by applying a metallization process such as plating, deposition, and sputtering. Generally, silver (Ag), which has excellent electrical conductivity, is used among conductive materials to minimize losses in RF equipment such as filters and waveguides, but conductive materials other than silver may be used to improve characteristics such as corrosion resistance. The metal layer 100b is formed not only on the inner surface of each of the through partition walls 121 and 122, but also on the inner surface of each of the plurality of resonance grooves 131 to 136, as shown in FIG.

When tuning is required in the ceramic waveguide filter 100 of this embodiment, tuning can be performed by adjusting the thickness of the metal layer 100b formed on the inner surfaces of the plurality of through- partition walls 121 and 122 by grinding or the like. can

On the other hand, input/ output interfaces 151 and 152 are formed in two resonance cavities 111 and 116 corresponding to the initial and final ends according to the designated coupling order among the plurality of resonance cavities 111 to 116 of the ceramic waveguide filter. do. Input/output interface ports (not shown) for inputting and outputting signals to and from the ceramic waveguide filter 100 may be inserted into the input/ output interfaces 151 and 152 .

The input/ output interfaces 151 and 152 may be formed on the other surface of the ceramic block 100a corresponding to the positions of the resonance grooves 131 and 136 in the two resonance cavities 111 and 116, which are the input/ output interfaces 151 and 152. This is to facilitate coupling between the input/output interface port inserted into the ) and the resonance grooves 131 and 136.

As shown in FIGS. 3 and 5 , the input/ output interfaces 151 and 152 in this embodiment are centered on the corresponding resonance grooves 131 and 136 in the metal layer 100b formed on the outer surface of the ceramic block 100a. The metal layer 100b may be formed by maintaining a circular shape having a predetermined size as a reference and removing the metal layer 100b by a predetermined distance from the circular shape. That is, it may be formed by removing the metal layer 100b at a position corresponding to the resonance grooves 131 and 136 on the other surface of the ceramic block 100a in a ring shape having a predetermined thickness. At this time, each of the inner and outer diameters of the ring shape removed from the metal layer 100b is, for example, the diameter r1 of the inlet portions 133a and 134a of the corresponding resonance grooves 131 and 136 and the end portions 133b and 134b. It may be set to the diameter (r2) of, but is not limited thereto. In addition, in some cases, the inside of the ring shape, that is, the region where the metal layer 100b is maintained is grooved so that the input/ output interfaces 151 and 152 can be easily coupled with the corresponding resonance grooves 131 and 136, respectively. It may be formed into a shape.

1 shows that the input/ output interfaces 151 and 152 are formed in the first resonant cavity 111 and the sixth resonant cavity 116 as an example, and thus the first resonant cavity 111 is connected to the input/output interface 151. A signal is applied from the input interface port, and coupling is performed between the first resonant cavity 111 and the second resonant cavity 112 . Coupling is performed in the order of the third to sixth resonant cavities 113 to 116 , and the sixth resonant cavity 116 outputs a signal to an output interface port connected to the input/output interface 152 .

Each of the plurality of resonance cavities 111 to 116 may resonate in a designated frequency band according to the size and shape defined by the plurality of through- partition walls 121 and 122 and the resonance grooves 131 to 136 . Therefore, in the ceramic waveguide filter according to the present embodiment, the plurality of resonant cavities 111 to 116 defined by the plurality of through- partition walls 121 and 122 perform multi-stage filtering of signals transmitted through the input interface port to output the signals to the output interface port. can be printed out.

At this time, in the ceramic waveguide filter 100, the first resonant cavity 111 is adjacent to the second resonant cavity 112 and the sixth resonant cavity 213, and the first through partition wall 121 is adjacent to the first resonant cavity 111. , Since the second resonant cavity 112 and the sixth resonant cavity 213 are not completely distinguished, the first resonant cavity 111 is coupled with the second resonant cavity 112, and together with the sixth resonant cavity (116) and cross-coupling is made.

In addition, since the first and second through partition walls 121 and 122 do not distinguish the second resonant cavity 112 and the fifth resonant cavity 115, the second resonant cavity 112 and the third resonant cavity 113 As the coupling is performed, cross-coupling with the fifth resonant cavity 115 is performed. Coupling is also performed in the third resonant cavity 113 and the fourth resonant cavity 114 .

Meanwhile, in the ceramic waveguide filter 100 according to the present embodiment, the resonant grooves 131 to 136 are formed in a cylindrical shape in an inward direction from one surface of the ceramic block 100a, and the diameter r2 at the inner end is one surface. A coupling groove 140 formed in a stepped structure that is rapidly or gradually wider than the diameter r1 in the third and fourth resonant cavities 113 and the fourth resonant cavity 114. Can be further formed between there is. The coupling groove 140 is formed to achieve a capacitive coupling between the third resonant cavity 113 and the fourth resonant cavity 114 in which an E-field acts predominantly. As shown in FIGS. 1 and 2, the coupling groove 40 is formed deeper than the resonant grooves 31 to 36 in order to achieve capacitive coupling between the resonant cavities. When the ring groove 40 is formed, there is a problem in that the risk of damage to the ceramic waveguide filter increases.

However, in this embodiment, the coupling groove 140 has a third diameter r3 similar to the resonance grooves 131 to 136 and has an inlet portion 141 formed in a cylindrical shape extending to a predetermined depth and a third diameter It has an end portion 142 having a fourth diameter r4 longer than (r3). That is, the cross section is formed as a step impedance structure having a T-shaped structure. Here, the length d2 to the end of the coupling groove 140 extending into the ceramic block 100a is set equal to the length d1 to the end of the resonance grooves 131 to 136 (d1 = d2) It can be.

At this time, the third diameter r3 of the inlet portion 141 of the coupling groove 140 is set equal to the first diameter r1, which is the diameter of the inlet portions 133a and 134a of the resonance grooves 131 to 136 However, the fourth diameter r4 of the end portion 142 is larger than the second diameter r2, which is the diameter of the end portions 133b and 134b of the resonance grooves 131 to 136. Here, in order to adjust the capacitance of the coupling groove 140, the fourth diameter r4 of the end portion 142 may be variously set.

While the existing coupling groove 40 is formed deeper than the resonance grooves 31 to 36, in this embodiment, the coupling groove 140 has a resonance groove 131 to 136 at a depth similar to that of the resonance grooves 131 to 136. 136) to have a larger capacitance. In this case, since the coupling groove 140 is formed to a depth similar to that of the resonance grooves 131 to 136, the risk of breakage of the ceramic waveguide filter 100 can be greatly reduced. In addition, the coupling groove 140 according to the present embodiment can have a smaller size and the same capacitance than the existing coupling groove 40, so that the size of the ceramic waveguide filter 100 can be further reduced.

In this embodiment, the coupling groove 140 operates with capacitive reactance in the pass band of the ceramic waveguide filter 100 . Also, the metal layer 100b is formed on the inner surface of the coupling groove 140 as in the plurality of resonance grooves 131 to 136 .

Although the case where the coupling groove 140 is formed between the third and fourth resonant cavities 113 and 114 is shown as an example in the above, the coupling groove 140 is the second and fifth resonant cavities 112 and 115 ) may be formed between the second resonant cavity 112 and the fifth resonant cavity 115 to achieve capacitive cross-coupling, or may be formed between other resonant cavities.

As a result, the ceramic waveguide filter 100 according to the present embodiment has a stepped impedance structure in which a plurality of resonance grooves 131 to 136 formed inwardly on one surface of the ceramic block 100a have a T-shaped cross section, and the ceramic block 100a has a stepped impedance structure. (100a) As the capacitance of the inner end portions 133b and 134b is greatly increased, it can be manufactured in a small size. In addition, the coupling groove 140 also has a step impedance structure with a T-shaped cross section like the plurality of resonance grooves 131 to 136, so that the size of the ceramic waveguide filter 100 can be further reduced and the risk of damage reduced can

7 to 10 are views for explaining an integrated ceramic waveguide filter according to a second embodiment of the present invention.

7 shows an upper perspective view of an integrated ceramic waveguide filter 200 according to a second embodiment of the present invention, FIG. 8 shows a lower perspective view, and FIG. 9 shows a projected plan view. And Figure 10 shows a side cross-sectional view. Here, FIG. 10 shows a cross-sectional view of the ceramic waveguide filter 200 taken along line A - A' of FIG. 9 .

In the integrated ceramic waveguide filter 200 of FIGS. 7 to 10 , a plurality of resonances defined by a plurality of penetrating barrier ribs 221 and 222 formed in a predetermined pattern penetrating between one surface and the other surface of a single ceramic block 200a. It is implemented as an integrated body including the cavities 211 to 216 . In addition, the plurality of through partition walls 221 and 222, the plurality of resonance grooves 231 to 236, and the input/ output interfaces 251 and 252 are the through partition walls 121 and 122 in the ceramic waveguide filter 100 of FIGS. 3 to 6. ) and the resonance grooves 131 to 136 and the input/ output interfaces 151 and 152 have the same structure. That is, the plurality of resonant grooves 231 to 236 have a first diameter r1 on one side of the ceramic block 200a and have a cylindrical inlet portion 233a, 234a extending to a predetermined depth and a first diameter. The terminal portion 233b and 234b having a second diameter r2 longer than (r1) may be formed as a step impedance structure having a T-shaped cross section.

However, in the ceramic waveguide filter 200 according to the second embodiment of the present invention, the coupling groove 140 of the ceramic waveguide filter 100 of FIGS. 3 to 6 is not formed, and the ceramic block 200a A coupling hole 240 penetrating the other side is formed on one side. Unlike the coupling groove 140, the coupling hole 240 is formed from one side of the ceramic block 200a through the other side, so that the risk of damage to the ceramic waveguide filter 200 can be further reduced.

Here, as shown in FIG. 10 , the coupling hole 240 has a diameter ( r5) can be formed with a smaller step structure. And, as shown in FIG. 10, a metal layer ( 200b) is formed. However, when the metal layer 200b is formed on the entire inner surface of the coupling hole 240, capacitive coupling is not easily achieved. Accordingly, as shown in FIG. 10, in the ceramic waveguide filter 200, the metal layer 200b is formed on the inner surface of the coupling hole 240 excluding the ring-shaped predetermined slot area 243, so that the capacitance Make a TV coupling.

Here, the ring-shaped slot area 243 may be formed at a predetermined position in the inlet area 242 of the coupling hole 240, and in particular, as shown in FIG. 10, the ceramic block 200a in the inlet area 242 It can be formed parallel to one side.

Here, the coupling hole 240 may be formed to have a smaller size than the coupling groove 140, which is advantageous for miniaturization of the ceramic waveguide filter 200.

11 to 14 are views for explaining an integral ceramic waveguide filter according to a third embodiment of the present invention.

Here, FIG. 11 shows an upper perspective view of the integrated ceramic waveguide filter 300 according to the third embodiment of the present invention, FIG. 12 shows a lower perspective view, and FIG. 13 shows a projected plan view. And Figure 14 shows a side cross-sectional view. 14 is a cross-sectional view of the ceramic waveguide filter 300 taken along line A - A' of FIG. 9 .

The integrated ceramic waveguide filter 300 of FIGS. 11 to 14 also includes a ceramic block 300a, a plurality of penetrating barrier ribs 321 and 322, and a plurality of through- partition walls 321 and 322, like the ceramic waveguide filter 300 according to the first and second embodiments. Since the resonant grooves 331 to 336 and the input/ output interfaces 351 and 352 have the same structure as the previously described ceramic waveguide filters 100 and 200, they are not described in detail here.

Also, in the ceramic waveguide filter 300 according to the third embodiment of the present invention, as in the second embodiment, coupling holes ( 340) is formed. However, in the ceramic waveguide filter 200 of the second embodiment, the coupling hole 240 is formed in a single step structure divided into through holes 241 having different diameters and inlet regions 242, whereas in the third In the ceramic waveguide filter 300 of the embodiment, the coupling hole 340 is located between the through hole 341 and the inlet region 342 as well as the through hole 341 and the inlet region 342 having different diameters, , an intermediate region 344 having a diameter between the through hole 341 and the inlet region 342 is further formed. In this way, when the coupling hole 340 has a two-stage step structure in which the middle region 344 is further formed, the resonance frequency can be further lowered, and the ceramic waveguide filter 300 can be miniaturized.

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

Referring to FIGS. 1 to 14, the manufacturing method of the ceramic waveguide filters 100, 200, and 300 of FIG. 15 will be described. First, ceramic blocks 100a, 200a, 300a) is prepared (S10). Here, the ceramic blocks 100a, 200a, and 300a may be manufactured with the size and shape determined according to the determined frequency band.

In addition, a plurality of penetration partition walls ((121, 122), (221, 222), (321, 322) penetrating one surface and the other surface of the ceramic block (100a, 200a, 300a) in a predetermined pattern according to a frequency band to be filtered ) to form a plurality of resonant cavities (111 to 116, 211 to 216, 311 to 316) by dividing the ceramic blocks 100a, 200a, and 300a into a plurality (S20).

A plurality of through partition walls (121, 122), (221, 222), and (321, 322) are formed to form a plurality of resonance cavities ((111 to 116), (211 to 216), and (311 to 316)). If implemented, a plurality of resonant grooves ((131 to 136), (231 to 236), (331 to 336)) can be formed (S30). Here, the plurality of resonance grooves (131 to 136), (231 to 236), and (331 to 336) are the respective regions of the plurality of resonance cavities (111 to 116), (211 to 216), and (311 to 316). may be formed to proceed in an inward direction from one surface of the ceramic blocks 100a, 200a, and 300a at a central position of the ceramic block 100a, 200a, and 300a to a predetermined depth of the first diameter r1 It is formed to be extended and is formed to have a second diameter r2 longer than the first diameter r1 at the end thereof, and has a step impedance structure having a T-shaped cross section. Since the capacitance at the end of the plurality of resonant grooves (131 to 136, 231 to 236, and 331 to 336) having a step impedance structure is greatly increased, the ceramic waveguide filters (100, 200, 300) can be manufactured in a small size.

Thereafter, a plurality of resonant cavities (111 to 116), (211 to 216), (311 to 316) pre-designated coupling grooves 140 so that capacitive coupling is performed between adjacent resonant cavities. Alternatively, coupling holes 240 and 340 are formed (S40). Whether to form the coupling groove 140 or the coupling holes 240 and 340 may be specified in advance. And, like the plurality of resonance grooves 131 to 136, the coupling groove 140 may be formed to have a step impedance structure having a T-shaped cross section. At this time, the diameter r4 at the ends of the coupling groove 140 may be set to be larger than the second diameter r2 at the ends of the resonance grooves 131 to 136 .

Meanwhile, when the coupling holes 240 and 340 are formed, the coupling holes 240 and 340 have a diameter r6 of the entrance area 242 on one surface of the ceramic block 200a, compared to the diameter r6 of the ceramic block 200a, The diameter (r5) of the through hole 241 penetrating through 300a may be formed in a step structure with a smaller diameter, and is located between the through hole 341 and the inlet region 342, and the through hole 341 and the inlet region ( 342) may be formed in a two-stage step structure further formed with an intermediate region 344 having a diameter between.

Further, when the coupling groove 140 or the coupling holes 240 and 340 are formed, the outer surface of the ceramic block 100a, 200a, and 300a and the plurality of through partition walls ((121, 122), (221, 222), (321, 322)), a plurality of resonance grooves ((131 to 136), (231 to 236), (331 to 336)), coupling grooves 140 or coupling holes (240, 340) Metal layers 100b, 200b, and 300b are formed (S50).

Then, it is determined whether the coupling holes 240 and 340 are formed (S60). If the coupling holes 240 and 340 are formed, at least one metal layer 200b and 300b formed on the inner surface of the coupling holes 240 and 340 is removed in a ring shape having a predetermined thickness at a predetermined position. Slots 243 and 343 are formed (S60). However, when the coupling groove 140 is formed, there is no need to form a slot.

Thereafter, input/output interfaces (151, 152, 251, 252, 351, 352) are formed in two of the plurality of resonance cavities (S70). Here, the input/output interfaces (151, 152), (251, 252), (351, 352) are a plurality of resonant cavities ((111 to 116), (211 to 216) of the ceramic waveguide filters (100, 200, 300). ), (311 ~ 316)) receives a signal from the input interface port, is sequentially coupled, and a plurality of resonant cavities ((111 ~ 116), (211 ~ 216) so that the filtered signal can be output to the output interface port , (311 to 316) may be formed at positions corresponding to the resonance cavities ((111, 116), (211, 216), (311, 316)) at both ends in the sequence of coupling. The input/output interfaces (151, 152), (251, 252), (351, 352) are resonant grooves (( 131, 136), (231, 236), (331, 336)), the metal layers 100b, 200b, and 300b formed on the other surfaces of the ceramic blocks 100a, 200a, and 300a are formed in a ring shape having a predetermined thickness. It can be formed by removing. At this time, the inner diameter of the ring corresponds to the first diameter r1 of the resonance grooves (131, 136, 231, 236, 331, 336), and the outer diameter corresponds to the second diameter r2. can be formed

Additionally, the manufacturing method of the ceramic waveguide filter according to the present invention includes the metal layers 100b, 200b, and 300b formed in the plurality of resonance grooves (131 to 136, 231 to 236, and 331 to 336), such as grinding. Tuning the characteristics of the ceramic waveguide filter by adjusting the resonant frequencies of the plurality of resonant cavities (111 to 116), (211 to 216), and (311 to 316) by adjusting the thickness. can

The method according to the present invention may be implemented as a computer program stored in a medium for execution on a computer. Here, computer readable media may be any available media that can be accessed by a computer, and may also include all computer storage media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, including read-only memory (ROM) dedicated memory), random access memory (RAM), compact disk (CD)-ROM, digital video disk (DVD)-ROM, magnetic tape, floppy disk, optical data storage device, and the like.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is only exemplary, and those skilled 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.

Claims (10)

1. a plurality of resonant cavities defined as compartments separated by a plurality of penetrating barrier ribs formed by penetrating a single ceramic block according to a predetermined pattern;

   Formed in an inward direction from one surface of the ceramic block within each of the plurality of resonant cavities partitioned by the through partition wall, the diameter at the one surface side of the ceramic block is formed smaller than the diameter at the inner end of the ceramic block multiple resonant grooves; and

   A ceramic waveguide filter comprising a metal layer formed on an outer surface of the ceramic block and an inner surface of each of the plurality of resonance grooves.
2. The method of claim 1, wherein each of the plurality of resonance grooves

   It is formed in a cylindrical shape extending from one surface side of the ceramic block to a predetermined depth with a predetermined first diameter, and is formed with a predetermined second diameter longer than the first diameter at the end thereof to have a T-shaped cross section. Waveguide filter.
3. The method of claim 1, wherein the ceramic waveguide filter

   It is formed in an inward direction from one surface of the ceramic block between at least two of the plurality of resonance cavities adjacent to each other, and the diameter at the one surface side of the ceramic block is smaller than the diameter at the inner end of the ceramic block, and the inner surface The ceramic waveguide filter further comprises at least one coupling groove in which the metal layer is formed.
4. The method of claim 3, wherein the at least one coupling groove

   The ceramic block is formed in a cylindrical shape extending from one surface side of the ceramic block to a predetermined depth with a predetermined third diameter, and is formed with a predetermined fourth diameter longer than the third diameter at the end thereof to have a T-shaped cross section. Waveguide filter.
5. The method of claim 3, wherein the at least one coupling groove

   A ceramic waveguide filter having a diameter at an inner end longer than a diameter at an inner end of the resonant groove.
6. The method of claim 3, wherein the at least one coupling groove

   A ceramic waveguide filter formed to the same depth as the plurality of resonant grooves in the ceramic block.
7. The method of claim 1, wherein the ceramic waveguide filter

   Formed through the ceramic block between at least two adjacent resonance cavities among the plurality of resonance cavities, wherein a diameter of a through hole penetrating the ceramic block is smaller than a diameter of an inlet region on one side of the ceramic block, The ceramic waveguide filter further comprising at least one coupling hole in which the metal layer is formed on an inner surface.
8. The method of claim 7, wherein the at least one coupling hole

   A ceramic waveguide filter further comprising an intermediate region having a diameter between a diameter of the through hole and a diameter of the inlet region between the through hole and the inlet region.
9. The method of claim 7, wherein the at least one coupling hole

   and a slot in which the metal layer is removed in a ring shape having a predetermined thickness at a predetermined position of the inlet region.
10. The method of claim 1, wherein the ceramic waveguide filter

    An input/output interface formed by removing the metal layer in a ring shape having a predetermined thickness at a position corresponding to a resonance groove formed in two resonance cavities for inputting and outputting signals among the plurality of resonance cavities on the other surface of the ceramic block. ceramic waveguide filter.

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