Multilayered ceramic waveguide filter

Abstract

The present invention relates to a multilayered ceramic waveguide filter comprising: a plurality of ceramic layers provided as a dielectric of a ceramic material and stacked in the thickness direction thereof; a plurality of resonator posts formed in at least a portion of the plurality of ceramic layers and, as one of resonant elements, penetrating in the thickness direction thereof; and a conductive metal pattern part arranged between at least two adjacent ceramic layers from among the plurality of ceramic layers, wherein the conductive metal pattern part is sintered simultaneously with the plurality of ceramic layers so as to be coupled to the ceramic layers, and thus the prevent invention provides the advantages of product miniaturization and improved product yield.

Description

Multilayer ceramic waveguide filter

[0001] The present invention relates to a multilayer ceramic waveguide filter, and more particularly, to a multilayer ceramic waveguide filter capable of manufacturing a compact product, minimizing insertion loss, having high frequency selectivity, and having a simple circuit structure to enhance controllability, thereby effectively improving overall yield.

[0002] With the recent proliferation of wireless communication services, the frequency landscape is becoming increasingly complex. Because frequencies for wireless communication are limited, there is a need to efficiently utilize frequency resources by ensuring that wireless communication channels are as close together as possible.

[0003] However, since signal interference frequently occurs in an environment where various wireless communication services are provided, the antenna includes a band filter for a specific band to minimize signal interference between adjacent frequency resources.

[0004] In general, to improve the attenuation characteristics of a bandpass filter, it is essential to apply a transmission zero (hereinafter referred to as a 'notch'), and this is implemented by applying cross coupling between non-adjacent resonant elements.

[0005] Among RF filters, ceramic waveguide filters contain a resonator for notch adjustment in a dielectric block surrounded by a conductive film. The resonator is designed to limit electromagnetic waves to specific frequencies by imparting resonant characteristics to them.

[0006] At this time, when cross-coupling is performed across an even number of resonators, symmetrical notches on the left and right of the pass band are generated, and when cross-coupling is performed across an odd number of resonators, one notch is usually generated on the left or right depending on the type of coupling.

[0007] The implementation of the notch of these communication filters needs to be implemented in a very diverse manner depending on the performance of the communication system, but the performance is limited in implementing a filter suitable for the characteristics of the communication system.

[0008] Accordingly, the filter needs to be set differently depending on the communication system so that notches can be implemented on the left and right of a specific passband in the antenna.

[0009] Fig. 1 is a perspective view showing an example of a ceramic waveguide filter for an antenna according to the prior art.

[0010] A ceramic waveguide filter (100) for an antenna according to the prior art includes, as illustrated in FIG. 1, six resonant blocks (111 to 116) partitioned by a partition wall (140) and six resonators (① to ⑥) provided in each of the resonant blocks (111 to 116), an input port (not shown) is connected to one of the six resonators (e.g., the first resonator (①)), and an output port (not shown) is connected to another of the six resonators (e.g., the sixth resonator (⑥)), and in the process of outputting a signal input through the input port through the output port, the resonance characteristics may vary depending on the individual shape of each resonant block (or the resonator posts (131 to 136) formed in each resonant block) and the size and position of the partition wall (140).

[0011] However, the ceramic waveguide filter (100) for an antenna according to the prior art has a very complex structure design for implementing left and right notches through coupling between resonators, as the resonance characteristics are varied only according to the shape of each resonant block (111 to 116), and since it is formed according to an integral molding manufacturing method of a ceramic material, it is difficult to insert an additional structure to implement cross coupling inside, which makes it difficult to design an effective coupling.

[0012] For example, most of the additional structures for implementing the left and right notches described above are made of conductive materials, but there is a problem that the method for installing additional structures made of conductive materials on ceramic materials, which are different materials, is very limited.

[0013]

[0014] The present invention has been devised to solve the above-mentioned technical problem, and its purpose is to provide a multilayer ceramic waveguide filter that can effectively improve the overall yield by enabling the manufacture of a more compact product, minimizing insertion loss, having high frequency selectivity, and having a simple circuit structure to enhance controllability.

[0015] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

[0016] A multilayer ceramic waveguide filter according to one embodiment of the present invention configured as described above comprises a plurality of ceramic layers laminated in the thickness direction, a plurality of resonator posts formed on at least a portion of the plurality of ceramic layers and penetrating in the thickness direction as one of the resonant elements, and a conductive metal pattern portion disposed between at least two adjacent ceramic layers among the plurality of ceramic layers, wherein the conductive metal pattern portion is fired simultaneously with the plurality of ceramic layers and is bonded to the ceramic layers.

[0017] Here, the conductive metal pattern portion may be disposed between adjacent ceramic layers among the plurality of ceramic layers, and may include an input port connection terminal that electrically connects an input port for inputting a signal to an adjacent resonator post among the plurality of resonator posts, and an output port connection terminal that electrically connects an output port for outputting a signal to an adjacent resonator post among the plurality of resonator posts.

[0018] In addition, the conductive metal pattern portion may further include an input port shielding pattern and an output port shielding pattern that shield the upper surfaces of the input port via hole and the output port via hole, which are provided with at least two ceramic layers that penetrate in the thickness direction to form the input port and the output port.

[0019] In addition, the conductive metal pattern portion may further include a strip line pattern disposed between adjacent ceramic layers among the plurality of ceramic layers and for implementing cross coupling among the plurality of resonator posts.

[0020] In addition, the strip line pattern may be arranged to be spaced apart from the outer surface of one of the plurality of resonator posts and the outer surface of the other so as to implement capacitive coupling by the cross coupling.

[0021] In addition, the plurality of resonator posts may further include a plurality of partition walls cut inwardly from the outer end to a predetermined depth so as to partition a plurality of resonant blocks, each of which is formed with a plurality of resonator posts, and the strip pattern line may be formed at a bridge end that is sintered and connected with a ceramic material so as to separate any one of the plurality of partition walls into two.

[0022] In addition, the bridge section may be placed between two adjacent ceramic layers among the plurality of ceramic layers when the two adjacent ceramic layers are formed by laminating each other.

[0023] In addition, the conductive metal pattern portion may further include a plurality of resonator panels having a predetermined diameter size arranged between adjacent ceramic layers among the plurality of ceramic layers and provided to cover the upper ends of the plurality of resonator posts.

[0024] Additionally, the plurality of resonator panels may be integrally formed on the lower surface of adjacent ceramic layers forming the plurality of resonator posts.

[0025] In addition, the plurality of ceramic layers may be formed by stacking 13 layers in the thickness direction, and the plurality of resonator posts may be formed such that at least some of them penetrate in the thickness direction, and then be formed by being coated with a metal film.

[0026] In addition, the plurality of resonator posts may further include a plurality of partition walls cut inward from the outer end to a predetermined depth so as to partition a plurality of resonant blocks, each of which is formed with a plurality of resonator posts.

[0027] In addition, the plurality of ceramic layers may further include a coupling adjustment post formed through the thickness direction to adjust the amount of coupling by adjacent coupling of at least two adjacent resonator posts among the plurality of resonator posts.

[0028] In addition, when the plurality of resonator posts are sequentially spaced apart from each other, including a first resonator post electrically connected to the input port, a fifth resonator post electrically connected to the output port, and a second resonator post, a third resonator post, and a fourth resonator post provided between the first resonator post and the fifth resonator post, a signal input through the input port is sequentially transmitted from the first resonator post to the second resonator post, the third resonator post, and the fourth resonator post to the fifth resonator post, and can be output to the outside through the output port.

[0029] In addition, adjacent coupling is sequentially formed between the first resonator post and the second resonator post and between the second resonator post and the third resonator post, and cross coupling is formed between the third resonator post and the first resonator post, but inductive coupling is implemented to form an L-notch on the right side of the pass band.

[0030] In addition, when a coupling adjustment post is further provided at each boundary portion of the first resonator post, the second resonator post, and the third resonator post, and is formed by penetrating the plurality of ceramic layers in the thickness direction, the coupling adjustment post can adjust the amount of coupling by adjacent coupling.

[0031] Additionally, when the strip line pattern is provided between the third resonator post and the fifth resonator post, capacitive coupling can be implemented between the third resonator post and the fifth resonator post.

[0032]

[0033] According to the multilayer ceramic waveguide filter of the present invention, the problem of insertion loss that was a problem when installing additional structures for existing ceramic materials to form notches (C-notches, L-notches) on both left and right sides of the pass band can be solved through the application of the LTCC technique, and there is an advantage in that a more compact product can be manufactured.

[0034] In addition, the frequency selectivity is improved, and the circuit structure is very simple, so controllability is excellent, which has the advantage of improving the product yield.

[0035]

[0036] Figure 1 is a perspective view showing an example of a ceramic waveguide filter for an antenna according to the prior art.

[0037] Figure 2 is a perspective view of the upper (a) and lower (b) exterior of a multilayer ceramic waveguide filter according to one embodiment of the present invention.

[0038] Figure 3 is an upper (a) and lower (b) perspective view showing the state in which the metal plating layer has been removed from the configuration of Figure 2 (a) and (b).

[0039] Figure 4 is a plan view of (a) and (b) of Figure 2,

[0040] Figure 5a is an exploded perspective view of each layer of Figure 3 (a),

[0041] Figure 5b is an exploded perspective view of each layer of Figure 3 (b),

[0042] Fig. 6a is a perspective view showing the first to ninth ceramic layers of the configuration of Fig. 3.

[0043] Fig. 6b is a perspective view showing the 10th ceramic layer of the configuration of Fig. 3,

[0044] Figure 6c is a perspective view showing the 11th ceramic layer among the configurations of Figure 3.

[0045] Figure 7 is a cutaway perspective view taken along line AA of Figure 3,

[0046] Fig. 8 is a cutaway perspective view taken along the BB line of Fig. 3.

[0047] FIG. 9 is a plan view illustrating the coupling appearance of a multilayer ceramic waveguide filter according to one embodiment of the present invention.

[0048]

[0049] <Explanation of symbols>

[0050] 1: Multilayer ceramic waveguide filter 11 to 15: Resonant block

[0051] 21; Input port 22: Output port

[0052] 31 to 35: Resonator posts 40-1 to 40-5: Bulkheads

[0053] 50: Coupling adjustment post 60: Bridge stage

[0054] 70: Stripline pattern 80: Resonator panel pattern

[0055] 90: Film

[0056]

[0057] Hereinafter, a multilayer ceramic waveguide filter according to an embodiment of the present invention will be described in detail with reference to the attached drawings. When adding reference numerals to components in each drawing, it should be noted that the same components are given the same numerals as much as possible even if they are shown in different drawings. In addition, when describing an embodiment of the present invention, if a specific description of a related known configuration or function is judged to hinder understanding of the embodiment of the present invention, the detailed description thereof will be omitted.

[0058] In describing components of embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by these terms. Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this application.

[0059]

[0060] FIG. 2 is an upper (a) and lower (b) perspective view of a multilayer ceramic waveguide filter according to one embodiment of the present invention, FIG. 3 is an upper (a) and lower (b) perspective view showing a state in which a metal plating layer has been removed among the configurations of FIG. 2 (a) and (b), and FIG. 4 is a plan view of FIG. 2 (a) and (b).

[0061] A communication antenna includes a filter for filtering signals of a specific passband. Depending on the characteristics, a cavity filter, a waveguide filter, etc. may be used as the filter. However, in an embodiment of the present invention, a ceramic waveguide filter using a ceramic material dielectric among the waveguide filters provided in the antenna will be described. However, one embodiment of the present invention may be limited to a multilayer ceramic waveguide filter in which a plurality of ceramic layers are laminated in a predetermined manner among the above-described ceramic waveguide filters.

[0062] As referenced in FIG. 1, the multilayer ceramic waveguide filter (1) according to the present invention includes a plurality of resonant blocks (11 to 15).

[0063] In general, a ceramic waveguide filter (1) includes at least four resonant blocks, and may include, for example, four to twenty resonant blocks in one filter.

[0064] The multilayer ceramic waveguide filter (1) according to the present invention is described as an example of one composed of five resonant blocks (refer to drawing reference numerals '11 to 15') as shown in FIGS. 2 to 4.

[0065] A multilayer ceramic waveguide filter (1) according to one embodiment of the present invention comprises a plurality of ceramic layers (refer to reference numerals '1L to 13L') made of a dielectric material of a ceramic material, which are laminated, and a conductive metal pattern portion (refer to reference numerals 21c, 22c, 70, 80 of FIGS. 2 to 9) is disposed between at least two adjacent ceramic layers among the plurality of ceramic layers (1L to 13L). Here, the conductive metal pattern portion can be manufactured to be bonded to the ceramic layers (1L to 13L) by a low temperature co-fired ceramics (LTCC) technique.

[0066] Specifically, low-temperature co-fired ceramics (LTCC) technology is a technology for manufacturing ceramics that form metal wiring (the aforementioned conductive metal pattern portion) inside by simultaneously firing a conductive metal and a ceramic that can be sintered at a low temperature. The material that makes up the conductive metal pattern portion is determined by considering electrical resistance, durability, cost, etc., and copper (Cu) can be selected as the most suitable material.

[0067] A multilayer ceramic waveguide filter (1) according to one embodiment of the present invention is formed with five resonant blocks (11 to 15) as one of the resonant elements, as shown in FIGS. 2 to 4, and each resonant block (11 to 15) is not completely physically separated, but at least part of it can be separated by a partition wall (40-1 to 40-5) described later.

[0068] The interior of each resonant block (11 to 15) is filled with a dielectric of a predetermined material, except for the resonator posts (31 to 35) and coupling adjustment posts (50) described later, and the dielectric material may be a ceramic material as described above. In the multilayer ceramic waveguide filter (1) according to one embodiment of the present invention, the dielectric material will be described as being limited to a ceramic material in order to apply the LTCC technology described above.

[0069] In addition, as described above, the outer surface of the plurality of ceramic layers (1L to 13L) laminated can be formed with a film portion (90) plated with a metal material to form a film with a predetermined thickness.

[0070] That is, the multilayer ceramic waveguide filter (1) has a film portion (90) over the entire outer surface, so that electrical signal transmission to and from the inside and the outside is completely blocked except for the input port (21) or the output port (22) described later, and the signal passing through the input port (21) and the output port (22) can be filtered in a state where the signal to and from the outside is blocked by the film portion (90). Referring to Fig. 2, it can be confirmed that the laminated appearance of a plurality of ceramic layers (1L to 13L) is not observed from the outside by the film portion (90).

[0071] Each of the plurality of resonant blocks (11 to 15) operates as one resonator (① to ⑤), and a multilayer ceramic waveguide filter (1) composed of five resonators (① to ⑤) can be formed through five resonant blocks (11 to 15).

[0072] More specifically, each resonator block (11 to 15) may be provided with a resonator post (31 to 35). The resonator post (31 to 35) is provided in the form of a cylinder (cylinder) cut out within each resonator block (11 to 15), and as described above, it is sufficient to understand that the inner portion cut out by the film portion (90) is formed with a film of a conductive material, thereby forming a metal cylinder.

[0073] However, the resonator posts (31 to 35) may be filled with a dielectric having a different permittivity from the ceramic material, but since air is also a type of dielectric having a predetermined permittivity, the resonator posts (31 to 35) may be defined as being formed in the form of an empty space in which a portion of each resonator block (11 to 15) is removed, assuming that the resonator posts (31 to 35) have the permittivity of air.

[0074] In the following, for convenience of explanation, it will be assumed that each resonator post (31 to 35) is provided in a hollow shape into which a dielectric having the permittivity of air is inserted. This should also be interpreted in the same way for the bulkheads (40-1 to 40-5) and coupling adjustment posts (50) described later.

[0075] The resonator posts (31 to 35) may be provided on the lower surface of each resonator block (11 to 15) of a plurality of ceramic layers (1L to 13L). Here, the precise meaning of the resonator posts (31 to 35) being provided on the lower surface may mean that the outer surface of each resonator post (31 to 35) is provided to match the lower surface.

[0076] When each resonator post (31 to 35) is made of air having a predetermined permittivity, being installed on the lower surface means that each opening direction is formed to open toward the lower surface.

[0077] The first to fifth resonant blocks (11 to 15) are combined with the first to fifth resonator posts (31 to 35) to operate as independent resonators.

[0078] A multilayer ceramic waveguide filter (1) according to one embodiment of the present invention may further include a plurality of partition walls (40-1 to 40-5) as a configuration for dividing each resonant block (11 to 15).

[0079] For example, the plurality of partition walls (40-1 to 40-5), as shown in FIGS. 2 and 4, include a first partition wall (40-1) formed to be cut inward (in the x direction) from the outer end between the first resonance block (11) and the second resonance block (12), a second partition wall (40-2) formed to be cut inward (in the y direction) from the outer end between the second resonance block (12) and the third resonance block (13), a third partition wall (40-3) formed to be cut inward (in the y direction) from the outer end between the third resonance block (13) and the fourth resonance block (14), and a fourth partition wall (40-4) and a fifth resonance block (15) formed to be cut inward (in the x direction) from the outer end between the fourth resonance block (14) and the fifth resonance block (15). It may include a fifth bulkhead (40-5) formed to be cut to a predetermined depth from the outer end to the inside (in the y direction) between the first resonance blocks (11).

[0080] Here, the depth of each cut of the first to fifth bulkheads (40-1 to 40-5) can be set differently according to the designer's final design value, and in particular, the fifth bulkhead (40-5) can be cut in an inclined shape in the x and y directions so as to physically completely partition the space between the adjacent fifth resonance block (15) and the first resonance block (11), as well as partition the space between the third resonance block (13) and the fifth resonance block (15).

[0081] In this way, the size and resonance characteristics of each resonance block (11 to 15) can be varied depending on the size (width, length) and position of a plurality of partition walls (40-1 to 40-5) cut to different depths between each resonance block (11 to 15) or a coupling adjustment post (50) described later.

[0082] For example, the amount of signal shielding between adjacent resonance blocks (11 to 15) is different depending on the shape of each partition wall (40-1 to 40-5), so the resonance characteristics are varied as originally designed.

[0083] Meanwhile, a multilayer ceramic waveguide filter (1) according to one embodiment of the present invention performs a function similar to that of the multiple partition walls (40-1 to 40-5) described above, and may further be provided with a coupling adjustment post (50) as referenced in FIGS. 2 and 3.

[0084] Here, the coupling adjustment post (50) may be provided in the form of a circular hole that penetrates the entirety of the plurality of ceramic layers (1L to 13L) in the thickness direction, unlike the plurality of resonator posts (31 to 35) described above, which are formed in a shape that is closed in the upper direction but open only in the lower direction.

[0085] In particular, in the multilayer ceramic waveguide filter (1) according to one embodiment of the present invention, the coupling adjustment post (50) is formed at each boundary portion of the first resonator post (31) of the first resonator block (11), the second resonator post (32) of the second resonator block (12), and the third resonator post (33) of the third resonator block (13), thereby performing the function of adjusting the amount of coupling between the first resonator post (31) - the second resonator post (32), the second resonator post (32) - the third resonator post (33), and the third resonator post (33) - the first resonator post (31).

[0086] In the embodiment of the present invention, the adjacent coupling between adjacent resonator posts is described as inductive coupling, i.e. L-coupling.

[0087] To prevent the amount of adjacent coupling (L-coupling) between adjacent resonator posts from increasing significantly and to maintain an appropriate amount of coupling, a coupling adjustment post (50) is provided between adjacent resonator posts.

[0088] Referring to FIG. 9, the coupling adjustment post (50) is formed at a predetermined distance from the first resonator post (31), the second resonator post (32), and the third resonator post (33), and can appropriately adjust the amount of coupling by reducing the strength of the L-coupling between the first resonator post (31) and the second resonator post (32), the L-coupling between the second resonator post (32) and the third resonator post (33), and the L-coupling between the third resonator post (33) and the first resonator post (31).

[0089] Meanwhile, a multilayer ceramic waveguide filter (1) according to one embodiment of the present invention may further include an input port (21) provided in the first resonant block (11) and provided on one side of the first resonator post (31), as shown in FIGS. 2 to 4, and an output port (22) provided in the fifth resonant block (15) and provided on one side of the fifth resonator post (32).

[0090] The input port (21) and the output port (22) are formed so as to be exposed to the lower surface so as to be electrically connected to the mounting surface of a main board (not shown) on which a multilayer ceramic waveguide filter (1) according to an embodiment of the present invention is fixed and mounted, and may further include an input port via hole (21h) and an output port via hole (22h) provided in the form of via holes penetrating through the first ceramic layer (1L) and the second ceramic layer (2L) close to the main board among a plurality of ceramic layers (1L to 13L) in the thickness direction, and an input port cut-off portion (21T) and an output port cut-off portion (22T) formed by annularly cutting a film portion (90) formed on the lower surface of the first ceramic layer (1L) and around the input port via hole (21h) and the output port via hole (22h), respectively (see FIGS. 8 and 9 described later).

[0091] Electrical signal connection is possible by forming a film using the film portion (90) described above on the inside of the input port empty hole (21h) and the output port empty hole (22h).

[0092] The input port (21) and output port (22) provided in this manner can be electrically connected to the first resonator post (31) and the fifth resonator post (35) through the input port connection terminal (21d) and the output port connection terminal (22d), which are each one of the conductive metal pattern portions formed on the upper surface of the second ceramic layer (2L) using the LTCC technology described above.

[0093] FIG. 5a is an exploded perspective view of each stack of (a) in FIG. 3, FIG. 5b is an exploded perspective view of each stack of (b) in FIG. 3, FIG. 6a is a perspective view showing the first to ninth ceramic layers in the configuration of FIG. 3, FIG. 6b is a perspective view showing the tenth ceramic layer in the configuration of FIG. 3, FIG. 6c is a perspective view showing the eleventh ceramic layer in the configuration of FIG. 3, FIG. 7 is a cutaway perspective view taken along line AA in FIG. 3, and FIG. 8 is a cutaway perspective view taken along line BB in FIG. 3.

[0094] A multilayer ceramic waveguide filter (1) according to one embodiment of the present invention may further include a plurality of ceramic layers (1L to 13L) laminated to be manufactured using the LTCC technique, as shown in FIGS. 5A to 6C.

[0095] Here, the LTCC technique is, as described above, a method of firing a conductive metal and sinterable ceramics simultaneously at a low temperature (particularly, 1250℃ or lower, preferably around 900℃). When a ceramic material is fired and formed at a high temperature, the ceramic properties deteriorate, and the conductive metal pattern portion melts during the firing process, causing a problem in that it cannot be manufactured in the shape originally designed. Therefore, to prevent this, the conductive metal is fired simultaneously with the ceramics at a low temperature.

[0096] Meanwhile, a plurality of ceramic layers (1L to 13L) laminated by the LTCC technique form 13 layers in the thickness direction in the case of one embodiment of the present invention, but as described above, since the entire outer surface is formed with a film of a predetermined thickness by the film portion (90), if it is assumed that the film portion (90) also forms a layer, it can be understood that a total of 15 layers are formed in the thickness direction.

[0097] Here, the bottom, which is relatively close to the main board and on which the above-described input port (21) and output port (22) are formed, is coated, corresponds to the input / output layer, and the top, which is the opposite side and on which the 13th ceramic layer (13L) is coated, corresponds to the ground metal layer.

[0098] The multiple ceramic layers (1L to 13L) may have different thicknesses, but may be approximately 0.1T (where T is a length unit in mm).

[0099] Here, a configuration commonly formed in a plurality of ceramic layers (1L to 13L) is described. As shown in FIGS. 5A and 5B, in a plurality of ceramic layers (1L to 13L), each of the first to fifth resonance blocks (11 to 15) is partitioned, and a plurality of partition walls (40-1 to 40-5) provided for shielding all or part of a signal according to a design value desired by the designer, and a coupling adjustment post (50) performing a similar function can be formed to penetrate in the thickness direction at a commonly corresponding outer end and position.

[0100] Below, the configuration individually formed in multiple ceramic layers (1L to 13L) is described as follows.

[0101] Referring to FIGS. 5A and 5B, at the same positions of the first to tenth ceramic layers (1L to 10L), circular holes of a predetermined size for forming the first to fifth resonator posts (31 to 35) can be formed to penetrate in the thickness direction.

[0102] Here, the first to fifth resonator posts (31 to 35) can be formed into a cylindrical (column) shape by, as described above, laminating and molding a circular hole using the LTCC technique and then coating the inside with a conductive material film (90).

[0103] At this time, the first to fifth resonator posts (31 to 35) may have an input / output layer portion, which is the lower portion close to the main board, open, and the upper portion opposite thereto may be closed by the 11th ceramic layer (11L) in which no circular hole is formed. In addition, the 12th ceramic layer (12L) and the 13th ceramic layer (13L) located at the upper portion of the 11th ceramic layer (11L) and the film portion (90) coated thereon may also be closed without forming a circular hole.

[0104] Here, on the lower surface of the 11th ceramic layer (11L), a resonator panel pattern (80) may be formed integrally, which is one of the conductive metal pattern portions described above and is arranged to cover and contact the upper ends of each of the first to fifth resonator posts (31 to 35). The resonator panel pattern (80) may be provided in the form of a metal disk that forms the inner end of each of the resonator posts (31 to 35).

[0105] That is, the resonator panel pattern (80) may be provided in the form of a disk of a circular panel of a conductive material, and may include the first to fifth resonator panels (81P to 85P) so as to cover the upper portions of each of the first to fifth resonator posts (31 to 35), as shown in FIG. 6c.

[0106] The first to fifth resonator panels (81P to 85P) may be formed to be at least larger than the diameter of the upper portion of each of the first to fifth resonator posts (31 to 35).

[0107] The first to fifth resonator panels (81P to 85P) are provided with the same conductive material as the aforementioned film portion (90) coated on the inner surface of the first to fifth resonator posts (31 to 35), and by designing the diameter sizes differently, the designer can design the panel to selectively raise or lower the frequency of the passband.

[0108] In one embodiment of the present invention, as shown in FIGS. 6A to 8, the first to fifth resonator posts (31 to 35) are formed only from the first ceramic layer (1L) to the tenth ceramic layer (10L), and the upper end is covered by the resonator panel pattern (80) formed on the eleventh ceramic layer (11L), but the present invention is not necessarily limited thereto. That is, it may also be possible for the resonator panel pattern (80) to be provided on the lower surface of the twelfth ceramic layer (12L) depending on the resonance characteristic design value.

[0109] Meanwhile, the first ceramic layer (1L) and the second ceramic layer (2L) may further be provided with a first input port hole (21a) and a first output port hole (22a) and a second input port hole (22b) and a second output port hole (22b) that penetrate in the thickness direction to form an input port (21) and an output port (22), which are among the conductive metal pattern portions described above.

[0110] In addition, on the lower surface of the third ceramic layer (3L), which is the surface facing the main board, an input port shielding pattern (21c) and an output port shielding pattern (22c) that shield the upper surface of the input port via hole (21h) and the output port via hole (22h) may be further provided.

[0111] The input port shielding pattern (21c) and the output port shielding pattern (22c) can be formed by simultaneously firing at low temperature after inserting the corresponding metal material between them before laminating the third ceramic layer (3L) on top of the second ceramic layer (2L) for forming using the LTCC technique.

[0112] In addition, on the upper surface of the second ceramic layer (2L), an input port connection terminal (21d) that electrically connects the outer surface of the input port via hole (21h) and the outer surface of the adjacent first resonator post (31), and an output port connection terminal (22d) that electrically connects the outer surface of the output port via hole (22h) and the outer surface of the adjacent fifth resonator post (35) can be formed using the LTCC technique.

[0113] Here, the input port empty hole (21h) and the output port empty hole (22h) are electrically isolated from the film part (90) by the input port short-circuit part (21T) and the output port short-circuit part (22T), so that a signal transmission path independent from the main board can be established, and the input and output of signals can be performed through the input port connection terminal (21d) and the output port connection terminal (22d).

[0114] In addition, the input port connection terminal (21d) and the output port connection terminal (22d) may be one of the design variable configurations that can be adjusted so that the resonance characteristics desired by the designer are implemented depending on the size of the width or the position in the direction of the formed thickness (i.e., the formed ceramic layer).

[0115] Meanwhile, a bridge section (60) may be formed in the 10th ceramic layer (10L) and the 11th ceramic layer (11L), which is sintered and connected with a ceramic material so as to separate the fifth partition wall (40-5) among the plurality of partition walls (40-1 to 40-5) into two. That is, the bridge section (60) may be formed by the 10th ceramic layer (10L) and the 11th ceramic layer (11L).

[0116] Here, a strip line pattern (70) for implementing cross coupling between the third resonator post (33) and the fifth resonator post (35) can be formed on the upper surface of the bridge section (60) of the 10th ceramic layer (10L) using the LTCC technique.

[0117] More specifically, the strip pattern line (70) is not involved in the formation of the fifth bulkhead (40-5) and is disposed between the tenth ceramic layer (10L) and the eleventh ceramic layer (11L) forming the bridge section (60) described above as an uncut portion, and can be formed using the LTCC technique described above.

[0118] At this time, the strip line pattern (70) is one of the conductive metal pattern portions described above, and is arranged at a predetermined distance from the outer surface of the third resonator post (33) and the outer surface of the fifth resonator post (35), thereby implementing capacitive coupling during cross coupling, thereby forming a C-notch.

[0119] That is, even when only the bridge (60) is formed between the third resonator post (33) and the fifth resonator post (35) without the strip line pattern (70), an L-notch implemented by inductive coupling during cross coupling is formed, but when the strip line pattern (70) is additionally provided spaced apart from each resonator post (33, 35), a C-notch implemented by capacitive coupling during cross coupling is formed.

[0120] Through this, the strip line pattern (70) plays a role in forming a transmission zero point in a relatively low frequency band compared to the pass band. Here, the designer can control the characteristics of the transmitted signal by controlling the width of the strip line pattern (70), its arrangement location, etc.

[0121] FIG. 9 is a plan view illustrating the coupling appearance of a multilayer ceramic waveguide filter according to one embodiment of the present invention.

[0122] A frequency filter process using a multilayer ceramic waveguide filter (1) according to one embodiment of the present invention configured as described above is briefly described below with reference to the attached drawings (particularly, FIG. 9).

[0123] As referenced in Fig. 9, a signal input through the input port (21) is sequentially transmitted from the first resonator post (31) to the second resonator post (32), the third resonator post (33), the fourth resonator post (34), and to the fifth resonator post (35), and is output to the outside through the output port (22).

[0124] Adjacent coupling is sequentially formed between the first resonator post (31) and the second resonator post (32) and between the second resonator post (32) and the third resonator post (33), and cross coupling is formed between the third resonator post (33) and the first resonator post (31). In particular, by implementing inductive coupling, an L-notch can be formed on the right side of the pass band.

[0125] At this time, the coupling adjustment post (50) is formed at an appropriate position at each boundary portion of the first resonance block (11), the second resonance block (12), and the third resonance block (13), so that the coupling amount of the adjacent coupling can be adjusted.

[0126] Here, if there is no structure such as a coupling adjustment post (50) at the boundary between the first resonance block (11), the second resonance block (12), and the third resonance block (13), the amount of coupling between the respective resonance blocks (11, 12, 13) may increase, and thus the above-described amount of coupling can be adjusted through appropriate position design of the coupling adjustment post (50).

[0127] Meanwhile, adjacent coupling may be sequentially formed between the third resonator post (33) and the fourth resonator post (34) and between the fourth resonator post (34) and the fifth resonator post (35), and cross coupling may be formed between the third resonator post (33) and the fifth resonator post (35). In particular, by implementing capacitive coupling by the above-described strip line pattern (70), a C-notch may be formed on the left side of the pass band. In addition, the strip line pattern (70) serves to form a C-notch having a transmission zero point in a lower frequency range than the band frequency between the third resonator post (33) and the fifth resonator post (35).

[0128] According to a multilayer ceramic waveguide filter (1) according to one embodiment of the present invention having such a configuration, the problem of insertion loss that was a problem when installing an additional structure for a conventional ceramic material to form a notch (C-notch, L-notch) on both left and right sides of the pass band can be solved by applying the LTCC technique, and more compact product manufacturing is possible, frequency selectivity is improved, and the circuit structure is very simple, so controllability is excellent, and it provides the advantage of effectively improving the yield of the product.

[0129]

[0130] Hereinafter, a multilayer ceramic waveguide filter (1) according to an embodiment of the present invention has been described in detail with reference to the attached drawings. However, the embodiment of the present invention is not necessarily limited to the above-described embodiment, and it will be understood that various modifications and equivalent implementations are possible by those skilled in the art to which the present invention pertains. Therefore, the true scope of the present invention is defined by the claims set forth below.

Claims

1. A dielectric material made of ceramic material and a plurality of ceramic layers laminated in the thickness direction; A plurality of resonator posts formed on at least a portion of the plurality of ceramic layers and penetrating in the thickness direction as one of the resonant elements; and A conductive metal pattern portion disposed between at least two adjacent ceramic layers among the plurality of ceramic layers; A multilayer ceramic waveguide filter, wherein the conductive metal pattern portion is simultaneously fired with the plurality of ceramic layers and bonded to the ceramic layers.

2. In claim 1, A multilayer ceramic waveguide filter, wherein the conductive metal pattern portion comprises: an input port connection terminal electrically connecting an input port for inputting a signal and an adjacent resonator post among the plurality of resonator posts, the input port connection terminal being arranged between adjacent ceramic layers among the plurality of ceramic layers; and an output port connection terminal electrically connecting an output port for outputting a signal and an adjacent resonator post among the plurality of resonator posts.

3. In claim 2, A multilayer ceramic waveguide filter, wherein the conductive metal pattern portion further includes an input port shielding pattern and an output port shielding pattern which shield upper surfaces of the input port via hole and the output port via hole, the input port shielding pattern and the output port shielding pattern having at least two ceramic layers penetrating in the thickness direction for forming the input port and the output port.

4. In claim 2, The above-mentioned challenging metal pattern portion, A multilayer ceramic waveguide filter further comprising a strip line pattern disposed between adjacent ceramic layers among the plurality of ceramic layers and for implementing cross-coupling among the plurality of resonator posts.

5. In claim 4, A multilayer ceramic waveguide filter, wherein the above strip line pattern is arranged spaced apart from the outer surface of one of the plurality of resonator posts and the other outer surface to implement capacitive coupling by the cross coupling.

6. In claim 4, It further includes a plurality of partitions cut inwardly from the outer end to a predetermined depth so that a plurality of resonant blocks, each of which has a plurality of resonator posts formed thereon, are partitioned; The above strip pattern line is a multilayer ceramic waveguide filter formed at a bridge section that is sintered and connected with a ceramic material so as to separate one of the plurality of partitions into two.

7. In claim 6, The above bridge section is a multilayer ceramic waveguide filter, which is disposed between two adjacent ceramic layers among the plurality of ceramic layers, when the two adjacent ceramic layers are laminated.

8. In claim 2, The above-mentioned challenging metal pattern portion, A multilayer ceramic waveguide filter further comprising: a plurality of resonator panels having a predetermined diameter, arranged between adjacent ceramic layers among the plurality of ceramic layers and arranged to cover the upper ends of the plurality of resonator posts; 9. In claim 8, A multilayer ceramic waveguide filter, wherein the plurality of resonator panels are integrally formed on the lower surface of adjacent ceramic layers forming the plurality of resonator posts.

10. In any one of claims 1 to 9, The above multiple ceramic layers are laminated in 13 layers in the thickness direction, A multilayer ceramic waveguide filter, wherein the above plurality of resonator posts are formed so that at least some of them penetrate in the thickness direction and are then coated with a metal film.

11. In any one of claims 1 to 9, A multilayer ceramic waveguide filter further comprising a coupling control post formed through the plurality of ceramic layers in the thickness direction to control the amount of coupling by adjacent coupling of at least two adjacent resonator posts among the plurality of resonator posts.

12. In claim 4, When the above plurality of resonator posts are sequentially spaced apart from each other, a first resonator post electrically connected to the input port, a fifth resonator post electrically connected to the output port, and a second resonator post, a third resonator post, and a fourth resonator post provided between the first resonator post and the fifth resonator post, A multilayer ceramic waveguide filter, wherein a signal input through the input port is sequentially transmitted from the first resonator post to the fifth resonator post through the second resonator post, the third resonator post, and the fourth resonator post, and output to the outside through the output port.

13. In claim 12, Between the first resonator post and the second resonator post and between the second resonator post and the third resonator post, adjacent couplings are sequentially formed, respectively. A multilayer ceramic waveguide filter in which cross coupling is formed between the third resonator post and the first resonator post, but inductive coupling is implemented to form an L-notch on the right side of the pass band.

14. In claim 12, When a coupling adjustment post is further provided at each boundary portion of the first resonator post, the second resonator post, and the third resonator post, which is formed by penetrating the plurality of ceramic layers in the thickness direction, The above coupling adjustment post is a multilayer ceramic waveguide filter that adjusts the amount of coupling by adjacent coupling.

15. In claim 12, A multilayer ceramic waveguide filter, wherein when the above strip line pattern is provided between the third resonator post and the fifth resonator post, capacitive coupling is implemented between the third resonator post and the fifth resonator post.

Images