Multilayer ceramic waveguide filter

Abstract

The present application relates to a kind of multilayer ceramic waveguide filters, comprising: multiple ceramic layers, by the dielectric body of ceramic material is formed, and in thickness direction layer is stacked;Multiple resonator columns, form in at least a portion of the multiple ceramic layers, as one of resonant elements through in the thickness direction;Conductive metal pattern part, between the adjacent 2 or more ceramic layers in the multiple ceramic layers;Wherein, the conductive metal pattern part is sintered simultaneously with the multiple ceramic layers to be combined to the ceramic layer;Further, the advantages that product miniaturization can be realized and product yield can be improved are provided.

Description

Technical Field

[0001] This invention relates to a multilayer ceramic waveguide filter, and more specifically, to a multilayer ceramic waveguide filter that can be manufactured into a compact product, minimizes insertion loss, has high frequency selectivity, and has a simple circuit structure that improves controllability, thereby effectively improving overall yield. Background Technology

[0002] Recently, with the increasing variety of wireless communication services, the frequency environment has become more complex. Since the frequencies available for wireless communication are limited, it is necessary to make wireless communication channels as adjacent as possible to effectively utilize frequency resources.

[0003] However, signal interference frequently occurs in environments that provide various wireless communication services. Therefore, in order to minimize signal interference between adjacent frequency resources, antennas include bandpass filters for specific frequency bands.

[0004] Typically, to improve the attenuation characteristics of a bandpass filter, a transmission zero (hereinafter referred to as a notch filter) must be applied, which is achieved by applying cross-coupling between non-adjacent resonant elements.

[0005] In RF filters, ceramic waveguide filters consist of a dielectric block surrounded by a conductive film, including a resonator for notch filtering. The resonator is designed to impart resonant characteristics to electromagnetic waves to limit specific frequencies.

[0006] At this point, if an even number of resonators are skipped for cross-coupling, a notch will usually appear symmetrically on the left and right sides of the passband; if an odd number of resonators are skipped for cross-coupling, a notch will usually appear on the left or right side depending on the type of coupling.

[0007] The implementation of notch filters for communication applications requires a wide variety of implementations depending on the performance of the communication system, but there are performance limitations in implementing filters suitable for the characteristics of the communication system.

[0008] Therefore, in terms of antennas, it is necessary to make different settings according to the communication system so that notch filtering can be achieved on the left and right sides of a specific passband.

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

[0010] like Figure 1As shown, the prior art antenna ceramic waveguide filter 100 includes: six resonant blocks (111 to 116) divided by a partition wall 140 and six resonators (① to ⑥) disposed in each of the resonant blocks (111 to 116); any one of the six resonators (e.g., the first resonator ①) is connected to an input port (not shown), and another of the six resonators (e.g., the sixth resonator ⑥) is connected to an output port (not shown). The resonant characteristics can be changed according to the shape of each resonant block (or the individual shape of the resonator pillars (131 to 136) formed in the resonant blocks) and the size and position of the partition wall 140 during the output process of the signal input through the input port.

[0011] However, according to the existing technology, the ceramic waveguide filter 100 for antennas changes its resonance characteristics only according to the shape of each resonator (111 to 116), and the structural design for the left and right notch filters realized by the coupling between the resonators is very complicated. At the same time, from the point of view that it is formed by the integral molding of ceramic material, it is difficult to insert additional structures inside to achieve cross coupling, so there is a problem that it is difficult to achieve an effective coupling design.

[0012] For example, there is a problem that most of the additional structures used to achieve the above-mentioned left and right notch filters are made of conductive materials, and the methods for setting additional structures of conductive materials in ceramic materials that are different from these are very limited. Summary of the Invention

[0013] (The problem to be solved)

[0014] This invention is proposed to solve the technical problems mentioned above. Its purpose is to provide a multilayer ceramic waveguide filter that can be manufactured into a more compact product, minimizes insertion loss, has high frequency selectivity, and has a simple circuit structure that improves controllability, thereby effectively improving the overall yield.

[0015] The subject matter of this invention is not limited to the subject matter mentioned above, and other subject matters not mentioned will be clearly understood by those skilled in the art from the following description.

[0016] (Solutions)

[0017] A multilayer ceramic waveguide filter according to an embodiment of the present invention configured as described above includes: a plurality of ceramic layers, which are made of a dielectric material of ceramic material and are stacked in the thickness direction; a plurality of resonator pillars formed in at least a portion of the plurality of ceramic layers and extending in the thickness direction as one of the resonant elements; and a conductive metal pattern portion disposed between two or more adjacent ceramic layers; wherein the conductive metal pattern portion is sintered simultaneously with the plurality of ceramic layers to bond to the ceramic layers.

[0018] Here, the conductive metal pattern portion may include: an input port connection terminal disposed between adjacent ceramic layers in the plurality of ceramic layers, and an input port for an input signal electrically connected to an adjacent resonator post in the plurality of resonator posts; and an output port connection terminal electrically connected to an output port for an output signal and an adjacent resonator post in the plurality of resonator posts.

[0019] In addition, the conductive metal pattern portion may also include an input port shielding pattern and an output port shielding pattern, which shield the top of the input port via and the output port via. The input port via and the output port via are formed by at least two ceramic layers that extend through the thickness direction to form the input port and the output port.

[0020] Additionally, the conductive metal pattern may include a strip pattern disposed between adjacent ceramic layers in the plurality of ceramic layers and used to achieve cross-coupling in the plurality of resonator pillars.

[0021] In addition, the strip pattern can be configured to be spaced apart from the outer peripheral surface of any one of the plurality of resonator pillars to achieve capacitive coupling through the cross coupling.

[0022] In addition, the multilayer ceramic waveguide filter also includes multiple partitions, which are cut to a predetermined depth from the outer end to the inner end to divide multiple resonant blocks that are respectively formed with multiple resonator pillars; the strip pattern can be formed at the bridging end, which is sintered with ceramic material to divide any one of the multiple partitions into two.

[0023] In addition, the bridging end is disposed between two adjacent ceramic layers when the plurality of ceramic layers are stacked.

[0024] In addition, the conductive metal pattern portion may also include a plurality of resonator panels disposed between adjacent ceramic layers in the plurality of ceramic layers and having a predetermined diameter to cover the upper ends of the plurality of resonator pillars.

[0025] In addition, the plurality of resonator panels may be integrally formed under a ceramic layer adjacent to the ceramic layer forming the plurality of resonator pillars.

[0026] In addition, the plurality of ceramic layers are stacked in the thickness direction in 13 layers, and the plurality of resonator pillars can be formed by at least a portion of them being formed through the thickness direction and then coated with a metal material coating portion.

[0027] In addition, the multilayer ceramic waveguide filter may also include multiple partitions, which are cut to a predetermined depth from the outer end to the inner end to divide multiple resonant blocks that are respectively formed with the multiple resonator pillars.

[0028] In addition, the multilayer ceramic waveguide filter may also include a coupling adjustment post, which is formed by penetrating the plurality of ceramic layers in the thickness direction, so as to adjust the coupling amount of adjacent coupling through at least two adjacent resonator posts among the plurality of resonator posts.

[0029] Furthermore, when the plurality of resonator pillars are arranged in a sequentially spaced manner, such that a first resonator pillar electrically connected to the input port, a fifth resonator pillar electrically connected to the output port, and a second, third, and fourth resonator pillar disposed between the first and fifth resonator pillars, the signal input through the input port is transmitted from the first resonator pillar through the second, third, and fourth resonator pillars to the fifth resonator pillar, and can be output to the outside through the output port.

[0030] In addition, adjacent coupling is sequentially achieved between the first resonator post and the second resonator post, and between the second resonator post and the third resonator post, respectively. Cross coupling is achieved between the third resonator post and the first resonator post, and inductive coupling is also achieved, thereby forming an L-notch filter on the right side of the passband.

[0031] In addition, when a coupling adjustment column formed by penetrating the multiple ceramic layers in the thickness direction is disposed at the boundary of the first resonator column, the second resonator column, and the third resonator column, the coupling adjustment column can adjust the coupling amount of adjacent couplings.

[0032] Furthermore, when the strip pattern is arranged between the third resonator post and the fifth resonator post, capacitive coupling can be achieved between the third resonator post and the fifth resonator post.

[0033] (The effect of the invention)

[0034] The multilayer ceramic waveguide filter according to the present invention has the following advantages: by applying LTCC technology, the insertion loss problem that exists when setting additional structures on existing ceramic materials to form notches (C notches, L notches) on the left and right sides of the passband can be solved. Moreover, it can also manufacture more miniaturized products.

[0035] In addition, it improves frequency selectivity, has a very simple circuit structure and excellent controllability, thus effectively improving product yield. Attached Figure Description

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

[0037] Figure 2 These are perspective views of the upper (a) and lower (b) parts of a multilayer ceramic waveguide filter according to an embodiment of the present invention.

[0038] Figure 3 It is shown Figure 2 Three-dimensional views of the upper (a) and lower (b) parts of the structures with the metal plating removed;

[0039] Figure 4 yes Figure 2 Plan views of (a) and (b);

[0040] Figure 5a yes Figure 3 The layer-by-layer decomposition of (a);

[0041] Figure 5b yes Figure 3 (b) is a layer-by-layer decomposition 3D diagram;

[0042] Figure 6a It is shown Figure 3 A three-dimensional view of the first to ninth ceramic layers in the structure;

[0043] Figure 6b It is shown Figure 3 A three-dimensional diagram of the tenth ceramic layer in the structure;

[0044] Figure 6c It is shown Figure 3 A three-dimensional diagram of the eleventh ceramic layer in the structure;

[0045] Figure 7 It is along Figure 3 A perspective 3D image captured by the AA line;

[0046] Figure 8 It is along Figure 3 A sectional perspective view taken from the BB line;

[0047] Figure 9 This is a plan view illustrating the coupling pattern of a multilayer ceramic waveguide filter according to an embodiment of the present invention.

[0048] (Explanation of reference numerals in the attached image)

[0049] 1: Multilayer ceramic waveguide filter; 11 to 15: Resonant block

[0050] 21: Input port 22: Output port

[0051] 31 to 35: Resonator pillars; 40-1 to 40-5: Divider

[0052] 50: Coupling adjustment post; 60: Bridging terminal

[0053] 70: Strip pattern; 80: Resonator panel pattern

[0054] 90: Coating Department Detailed Implementation

[0055] Hereinafter, a multilayer ceramic waveguide filter according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. When affixing reference numerals to components in the various drawings, care should be taken to ensure that identical components are used as much as possible, even when shown in different drawings. Furthermore, when describing embodiments of the present invention, if it is determined that a detailed description of a known structure or function would hinder understanding of the embodiments of the present invention, such detailed description will be omitted.

[0056] When describing the components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are merely used to distinguish the component from other components and should not limit the nature or order of the component. Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having the same meaning as in related technical articles and should not be interpreted in an ideal or overly formal sense unless expressly defined herein.

[0057] Figure 2 These are perspective views of the upper (a) and lower (b) parts of a multilayer ceramic waveguide filter according to an embodiment of the present invention. Figure 3 It is shown Figure 2 Three-dimensional views of the upper (a) and lower (b) parts of the structures with the metal plating removed; Figure 4 yes Figure 2 Plan views (a) and (b).

[0058] Communication antennas include filters for filtering signals in a specific passband. Depending on their characteristics, filters can be cavity filters, waveguide filters, etc., but in embodiments of the present invention, the focus is on ceramic waveguide filters using a dielectric material of ceramic material in the waveguide filter of the antenna configuration. However, in one embodiment of the present invention, the ceramic waveguide filter described above may also be limited to a multilayer ceramic waveguide filter that stacks multiple ceramic layers in a predetermined manner.

[0059] like Figure 2 As shown, the multilayer ceramic waveguide filter 1 according to the present invention includes a plurality of resonant blocks (11 to 15).

[0060] Typically, a ceramic waveguide filter 1 includes four or more resonant blocks; for example, a filter may include four to 20 resonant blocks.

[0061] like Figures 2 to 4 As shown, the multilayer ceramic waveguide filter 1 according to the present invention will be described as an example consisting of 5 resonant blocks (refer to reference numerals "11 to 15" in the accompanying drawings).

[0062] According to an embodiment of the present invention, a multilayer ceramic waveguide filter 1 comprises stacked multiple ceramic layers (referring to reference numerals "1L to 13L") made of a dielectric material of ceramic material, wherein conductive metal pattern portions are disposed between two or more adjacent ceramic layers (for example, referring to...). Figures 2 to 9 (Referring to reference numerals 21c, 22c, 70, 80). Here, the conductive metal patterned portion can be manufactured by bonding it to a ceramic layer (1L to 13L) using low-temperature co-fired ceramic (LTCC) technology.

[0063] Specifically, low-temperature co-fired ceramic (LTCC) technology is a technique that simultaneously sintersects a conductive metal with a sinterable ceramic at low temperatures to create ceramics with internal metal wiring (the aforementioned conductive metal patterned portion). The material constituting the conductive metal patterned portion is determined considering factors such as resistance, durability, and cost; copper (Cu) is the most suitable material.

[0064] like Figures 2 to 4 As shown, according to an embodiment of the present invention, the multilayer ceramic waveguide filter 1 is formed as one of the resonant elements, comprising five resonant blocks (11 to 15). Each resonant block (11 to 15) is not completely physically distinguished, but at least a portion of them can be distinguished by the partitions (40-1 to 40-5) described later.

[0065] The interior of each resonator block (11 to 15), except for the resonator pillars (31 to 35) and coupling adjustment pillar 50 described later, is filled with a dielectric material of a predetermined material. As mentioned above, the dielectric material can be ceramic. In the multilayer ceramic waveguide filter 1 according to an embodiment of the present invention, the dielectric material is described in the context of ceramic material in order to be applicable to the above-described LTCC technology.

[0066] Meanwhile, the outer surfaces of the multiple ceramic layers (1L to 13L) stacked as described above are all coated with a coating portion 90 of a predetermined thickness using a metal material.

[0067] That is, the entire exterior of the multilayer ceramic waveguide filter 1 is completely blocked by the coating section 90, except for the input port 21 or output port 22 described later for transmitting electrical signals to the inside and outside. This allows filtering of signals passing through the input port 21 and output port 22 while the coating section 90 shields the signal from external transmission. (Refer to...) Figure 2 The diagram shows that the stacked ceramic layers (1L to 13L) cannot be observed from the outside because of the coating section 90.

[0068] Multiple resonant blocks (11 to 15) operate as resonators (① to ⑤) respectively. A multilayer ceramic waveguide filter 1 composed of five resonators (① to ⑤) can be formed by using five resonant blocks (11 to 15).

[0069] More specifically, resonator pillars (31 to 35) may be configured in each resonator block (11 to 15). The resonator pillars (31 to 35) are configured in the form of a cylinder (circumference) cut within each resonator block (11 to 15). As described above, the inner portion of the cut is coated with a conductive material by the coating portion 90. This can be understood as a metal cylinder.

[0070] However, a dielectric material with a dielectric constant different from that of ceramic material can be inserted (filled) into the resonator pillars (31 to 35). However, air is usually a dielectric material with a predetermined dielectric constant. Therefore, the resonator pillars (31 to 35) can be defined as forming each resonator pillar (31 to 35) as a blank space form with a portion of each resonator block (11 to 15) removed, assuming that the dielectric constant of air is taken into account.

[0071] For ease of explanation, the following description assumes that each resonator post (31 to 35) is configured in a hollow shape with a dielectric material having an air dielectric constant inserted. The same explanation applies to the partition walls (40-1 to 40-5) and coupling adjustment post 50, which will be described later.

[0072] The resonator pillars (31 to 35) may be disposed below each of the resonator blocks (11 to 15) of the plurality of ceramic layers (1L to 13L). Here, the precise meaning of the resonator pillars (31 to 35) being disposed below is that they are configured such that the outer surface of the resonator pillars (31 to 35) matches the surface below.

[0073] When each resonator pillar (31 to 35) is made of air with a predetermined dielectric constant, "located below" means that each opening is oriented downwards.

[0074] The first to fifth resonant blocks (11 to 15) are combined with the first to fifth resonator pillars (31 to 35) to operate as independent resonators.

[0075] According to an embodiment of the present invention, the multilayer ceramic waveguide filter 1, as a structure for dividing the individual resonant blocks (11 to 15), may also include a plurality of partitions (40-1 to 40-5).

[0076] For example, such as Figure 2 and Figure 4 As shown, the plurality of partitions (40-1 to 40-5) may include: a first partition 40-1, formed by cutting a predetermined depth from the outer end between the first resonant block 11 and the second resonant block 12 inward (x direction); a second partition 40-2, formed by cutting a predetermined depth from the outer end between the second resonant block 12 and the third resonant block 13 inward (y direction); a third partition 40-3, formed by cutting a predetermined depth from the outer end between the third resonant block 13 and the fourth resonant block 14 inward (y direction); a fourth partition 40-4, formed by cutting a predetermined depth from the outer end between the fourth resonant block 14 and the fifth resonant block 15 inward (x direction); and a fifth partition 40-5, formed by cutting a predetermined depth from the outer end between the fifth resonant block 15 and the first resonant block 11 inward (y direction).

[0077] Here, the cutting depths of the first to fifth partitions (40-1 to 40-5) can be set differently according to the final design value of the designer; in particular, the fifth partition 40-5 can be cut into an inclined shape in the x and y directions, which can not only physically and completely separate the fifth resonant block 15 from the first resonant block 11, but also separate the third resonant block 13 from the fifth resonant block 15.

[0078] As described above, the size and resonance characteristics of each resonant block (11 to 15) can be changed by cutting partitions (40-1 to 40-5) of different depths or by adjusting the size (width, length) and position of the coupling adjustment column 50 described later.

[0079] For example, the amount of signal shielding between adjacent resonant blocks (11 to 15) varies depending on the shape of the partitions (40-1 to 40-5), thus altering the resonant characteristics according to the original design intent.

[0080] On the other hand, according to an embodiment of the present invention, the multilayer ceramic waveguide filter 1 is a structure that performs a function similar to the aforementioned plurality of partitions (40-1 to 40-5), such as... Figure 2 and Figure 3 As shown, a coupling adjustment column 50 can also be configured.

[0081] Here, in contrast to the plurality of resonator pillars (31 to 35) that are formed in a shape that is closed in the upper direction and open only in the lower direction, the coupling adjustment pillar 50 can be configured as a circular hole shape that allows all of the plurality of ceramic layers (1L to 13L) to pass through in the thickness direction.

[0082] In particular, in a multilayer ceramic waveguide filter 1 according to an embodiment of the present invention, coupling adjustment posts 50 are formed at the boundary locations 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 enabling the coupling adjustment function between the first resonator post 31 and the second resonator post 32, the second resonator post 32 and the third resonator post 33, and the third resonator post 33 and the first resonator post 31.

[0083] In the embodiments of the present invention, the adjacent coupling between adjacent resonator pillars is described as inductive coupling, i.e., L-coupling.

[0084] To prevent a significant increase in the amount of adjacent coupling (L-coupling) between adjacent resonator pillars and to maintain an appropriate amount of coupling, coupling adjustment pillars 50 are configured between adjacent resonator pillars.

[0085] Reference Figure 9 The coupling adjustment column 50 is formed by spacing a predetermined distance between the first resonator column 31, the second resonator column 32, and the third resonator column 33, and reduces the strength of the L-coupling between the first resonator column 31 and the second resonator column 32, the L-coupling between the second resonator column 32 and the third resonator column 33, and the L-coupling between the third resonator column 33 and the first resonator column 31, thereby allowing for appropriate adjustment of the amount of coupling.

[0086] On the other hand, such as Figures 2 to 4 As shown, the multilayer ceramic waveguide filter 1 according to an embodiment of the present invention may further include: an input port 21, disposed within the first resonant block 11 and on one side of the first resonator post 31; and an output port 22, disposed within the fifth resonant block 15 and on one side of the fifth resonator post 35.

[0087] The input port 21 and output port 22 may further include: an input port via 21h and an output port via 22h, exposed downwards to allow electrical connection to the mounting surface of a motherboard (not shown) for fixing and mounting the multilayer ceramic waveguide filter 1 according to an embodiment of the present invention, and configured to penetrate in the thickness direction through the via shape of the first ceramic layer 1L and the second ceramic layer 2L of the motherboard among multiple ceramic layers (1L to 13L); an input port power-off portion 21T and an output port power-off portion 22T, formed below the first ceramic layer 1L, and formed by cutting the coated portion 90 formed on the periphery of the input port via 21h and the output port via 22h into a ring shape (see below). Figure 8 and Figure 9 ).

[0088] The interior of the input port via 21h and the output port via 22h is also coated with the above-mentioned coating part 90, thereby enabling electrical signal connection.

[0089] The input port 21 and output port 22 configured as described above 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, respectively. The input port connection terminal 21d and the output port connection terminal 22d are one of the conductive metal pattern portions formed on the second ceramic layer 2L by the above-mentioned LTCC technology.

[0090] Figure 5a yes Figure 3 The layer-by-layer decomposition of (a); Figure 5b yes Figure 3 (b) is a layer-by-layer decomposition 3D diagram; Figure 6a It is shown Figure 3 A three-dimensional view of the first to ninth ceramic layers in the structure; Figure 6b It is shown Figure 3 A three-dimensional diagram of the tenth ceramic layer in the structure; Figure 6c It is shown Figure 3 A three-dimensional diagram of the eleventh ceramic layer in the structure; Figure 7 It is along Figure 3 A perspective 3D image captured by the AA line; Figure 8 It is along Figure 3 A sectional perspective view taken from the BB line.

[0091] like Figures 5a to 6c As shown, the multilayer ceramic waveguide filter 1 according to an embodiment of the present invention may further include multilayer ceramic layers (1L to 13L) stacked for manufacturing by LTCC technology.

[0092] Here, as mentioned above, LTCC technology is a process of simultaneously sintering conductive metals and sinterable ceramics at low temperatures (especially below 1250°C; preferably around 900°C). When ceramic materials are sintered and formed at high temperatures, the ceramic properties deteriorate, and the conductive metal pattern melts during the sintering process, resulting in a problem where the material cannot be manufactured according to the originally designed shape. In order to prevent this problem, conductive metals and ceramics are simultaneously sintered at low temperatures.

[0093] On the other hand, the multiple ceramic layers (1L to 13L) formed by LTCC technology are, in one embodiment of the present invention, 13 layers are formed in the thickness direction. However, as described above, the outer surface is covered with a predetermined thickness by the coating part 90. From this point of view, assuming that the coating part 90 is also formed as a layer, it can be understood that a total of 15 layers are formed in the thickness direction.

[0094] Here, the lower part of the first ceramic layer 1L covered with a film that is relatively close to the motherboard and has the aforementioned input port 21 and output port 22 is equivalent to the input / output layer, and the upper part of the thirteenth ceramic layer 13L covered with a film that is the opposite side is equivalent to the ground metal layer.

[0095] The thickness of the multiple ceramic layers (1L to 13L) can vary from one another, but can be around 0.1T (here, T is a unit of length and refers to mm).

[0096] Here, we will explain the structure formed by multiple ceramic layers (1L to 13L), such as Figure 5a and Figure 5b As shown, in multiple ceramic layers (1L to 13L), partitions (40-1 to 40-5) and coupling adjustment columns 50 performing similar functions are formed in a thickness direction to form common corresponding outer ends and positions. These partitions (40-1 to 40-5) respectively divide the first resonant blocks to the fifth resonant blocks (11 to 15) and are configured to shield all or part of the signals according to the design values ​​desired by the designer.

[0097] The following describes the structure formed individually in multiple ceramic layers (1L to 13L).

[0098] Reference Figure 5a and Figure 5b A circular hole of a predetermined size can be formed at the same position in the thickness direction of the first to tenth ceramic layers (1L to 10L) to form the first to fifth resonator pillars (31 to 35).

[0099] Here, as described above, the first to fifth resonator pillars (31 to 35) can be formed into a cylindrical (circumferential) shape after the circular holes are laminated using LTCC technology and the conductive material coating portion 90 is coated inside.

[0100] At this time, the first to fifth resonator pillars (31 to 35) serve as openings in the input / output layer near the lower end of the motherboard, and the upper end on the opposite side can be closed by the eleventh ceramic layer 11L, which does not have a circular hole. Furthermore, the twelfth ceramic layer 12L and the thirteenth ceramic layer 13L located at the upper end of the eleventh ceramic layer 11L, as well as the coating portion 90 on which this layer is coated, may also be closed without forming a circular hole.

[0101] Here, the lower surface of the eleventh ceramic layer 11L, as one of the aforementioned conductive metal patterned portions, can integrally form a resonator panel pattern 80, which is configured to cover and contact the upper ends of each of the first to fifth resonator pillars (31 to 35). The resonator panel pattern 80 can be configured to form a metal disk shape forming the inner end of each resonator pillar (31 to 35).

[0102] That is, the resonator panel pattern 80 can be configured as a disk shape of a circular panel made of conductive material, such as... Figure 6c As shown, it may include a first resonator panel to a fifth resonator panel (81P to 85P) covering the upper end of each of the first resonator pillars to the fifth resonator pillars (31 to 35).

[0103] The first to fifth resonator panels (81P to 85P) may be formed to be at least larger than the diameter of the upper circle of each of the first to fifth resonator pillars (31 to 35).

[0104] The first to fifth resonator panels (81P to 85P) are made of the same conductive material as the coating portion 90 on the inner circumferential surface of the first to fifth resonator pillars (31 to 35), and different diameters are designed so that the designer can selectively increase or decrease the passband frequency.

[0105] like Figures 6a to 8 As shown, in one embodiment of the present invention, a structure is disclosed in which the first resonator pillar to the fifth resonator pillar (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. However, it is not limited to this. That is, according to the design value of the resonance characteristics, the resonator panel pattern 80 can also be arranged on the lower surface of the twelfth ceramic layer 12L.

[0106] On the other hand, the first ceramic layer 1L and the second ceramic layer 2L may also be configured 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, which are through in the thickness direction to form one of the above-mentioned conductive metal pattern portions.

[0107] Additionally, in the third ceramic layer 3L, an input port shielding pattern 21c and an output port shielding pattern 22c can be configured on the underside of the surface facing the motherboard to shield the top of the input port via 21h and the output port via 22h.

[0108] The input port shielding pattern 21c and the output port shielding pattern 22c are designed to achieve LTCC technology. Before stacking the third ceramic layer 3L on top of the second ceramic layer 2L, the corresponding metal material is inserted between them and then sintered at low temperature.

[0109] Meanwhile, using LTCC technology, an input port connection terminal 21d and an output port connection terminal 22d can be formed on the second ceramic layer 2L. The input port connection terminal 21d is electrically connected to the outer peripheral surface of the input port via 21h and the outer peripheral surface of the adjacent first resonator post 31. The output port connection terminal 22d is electrically connected to the outer peripheral surface of the output port via 22h and the outer peripheral surface of the adjacent fifth resonator post 35.

[0110] Here, the input port via 21h and the output port via 22h are disconnected from the coating section 90 through the input port power-off section 21T and the output port power-off section 22T, thus configuring an independent signal transmission path from the motherboard, which can perform the function of inputting and outputting signals through the input port connection terminal 21d and the output port connection terminal 22d.

[0111] In addition, the input port connection terminal 21d and the output port connection terminal 22d can be one of the design variable structures, which can be adjusted according to the size of their width or the position in the thickness direction (i.e., the formed ceramic layer) to achieve the resonant characteristics desired by the designer.

[0112] On the other hand, bridging ends 60, which are sintered and connected by ceramic materials, can be formed in the tenth ceramic layer 10L and the eleventh ceramic layer 11L respectively, so as to divide the fifth partition 40-5 of the plurality of partitions (40-1 to 40-5) into two. That is, the bridging ends 60 can be formed through the tenth ceramic layer 10L and the eleventh ceramic layer 11L.

[0113] Here, using LTCC technology, a strip pattern 70 can be formed on the top of the bridging end 60 of the tenth ceramic layer 10L to achieve cross-coupling between the third resonator post 33 and the fifth resonator post 35.

[0114] More specifically, the strip pattern 70, as an uncut portion that does not participate in the formation of the fifth partition 40-5, is disposed between the tenth ceramic layer 10L and the eleventh ceramic layer 11L that form the aforementioned bridging end 60, and can be formed by the aforementioned LTCC technology.

[0115] At this time, the strip pattern 70, as one of the aforementioned conductive metal pattern portions, is arranged at a predetermined distance from the outer peripheral surfaces of the third resonator post 33 and the fifth resonator post 35, respectively, to achieve capacitive coupling in cross-coupling, thereby performing the function of forming a C-notch filter.

[0116] That is, when there is no stripline pattern 70 between the third resonator post 33 and the fifth resonator post 35, but only a bridge end 60 is formed, an L-notch filter can be formed through inductive coupling in cross coupling. However, when stripline patterns 70 are added at intervals to each resonator post (33, 35), a C-notch filter can be formed through capacitive coupling in cross coupling.

[0117] Accordingly, the stripline pattern 70 functions to create transmission zeros in the relatively low frequency band of the passband. Designers can adjust the characteristics of the transmitted signal by varying the width and placement of the stripline pattern 70.

[0118] Figure 9 This is a plan view illustrating the coupling pattern of a multilayer ceramic waveguide filter according to an embodiment of the present invention.

[0119] Refer to the attached figures (especially, Figure 9 The following is a brief description of the frequency filtering process using a multilayer ceramic waveguide filter 1 constructed as described above according to an embodiment of the present invention.

[0120] like Figure 9 As shown, the signal input through the input port 21 is transmitted sequentially from the first resonator post 31 through the second resonator post 32, the third resonator post 33, the fourth resonator post 34 to the fifth resonator post 35, and is output to the outside through the output port 22.

[0121] Adjacent couplings are sequentially achieved 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. Cross coupling is achieved between the third resonator post 33 and the first resonator post 31, especially inductive coupling, which can then form an L-notch wave on the right side of the passband.

[0122] At this time, the coupling adjustment column 50 is formed at appropriate positions at the boundary parts of the first resonant block 11, the second resonant block 12, and the third resonant block 13, thereby adjusting the coupling amount of adjacent couplings.

[0123] Here, in the absence of a structure such as the coupling adjustment column 50 at the boundary between the first resonant block 11 and the second resonant block 12 and the third resonant block 13, the coupling amount between the resonant blocks (11, 12, 13) can be increased. Therefore, the coupling amount can be adjusted by appropriately designing the position of the coupling adjustment column 50.

[0124] On the other hand, adjacent couplings are sequentially achieved 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, respectively, and cross coupling can be achieved between the third resonator post 33 and the fifth resonator post 35. In particular, capacitive coupling is achieved through the aforementioned stripline pattern 70, thereby forming a C-notch on the left side of the passband. Furthermore, the stripline pattern 70 performs the function of forming a C-notch, which has a transmission zero in the low-frequency region lower than the passband frequency between the third resonator post 33 and the fifth resonator post 35.

[0125] According to an embodiment of the present invention, a multilayer ceramic waveguide filter 1 with the above-described structure can solve the insertion loss problem when additional structures are set on existing ceramic materials to form notches (C-notches, L-notches) on the left and right sides of the passband by applying LTCC technology. Moreover, it can also manufacture more miniaturized products, improve frequency selectivity, and has a very simple circuit structure with excellent controllability, thus providing the advantage of effectively improving product yield.

[0126] The multilayer ceramic waveguide filter 1 according to an embodiment of the present invention has been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the one described above, and various modifications and equivalent implementations can certainly be made by those skilled in the art. Therefore, the true scope of the present invention should be defined by the claims.

Claims

1. A multilayer ceramic waveguide filter, comprising: Multiple ceramic layers, composed of dielectric ceramic materials, are stacked in the thickness direction; Multiple resonator pillars, formed in at least a portion of the multiple ceramic layers, extend through the thickness direction as one of the resonant elements; and A conductive metal pattern portion is disposed between two or more adjacent ceramic layers in the plurality of ceramic layers; The conductive metal pattern portion is sintered simultaneously with the plurality of ceramic layers to bond to the ceramic layers.

2. The multilayer ceramic waveguide filter according to claim 1, characterized in that, The conductive metal pattern portion includes: an input port connection terminal disposed between adjacent ceramic layers in the plurality of ceramic layers, and an input port for electrically connecting an input signal to an adjacent resonator post in the plurality of resonator posts; and an output port connection terminal electrically connected to an output port for connecting an output signal to an adjacent resonator post in the plurality of resonator posts.

3. The multilayer ceramic waveguide filter according to claim 2, characterized in that, The conductive metal pattern portion further includes an input port shielding pattern and an output port shielding pattern, which shield the top of the input port via and the output port via. The input port via and the output port via are formed by at least two ceramic layers extending in the thickness direction to form the input port and the output port.

4. The multilayer ceramic waveguide filter according to claim 2, characterized in that, The conductive metal patterned portion also includes a strip line pattern. The strip pattern is configured between adjacent ceramic layers in the plurality of ceramic layers and is used to achieve cross coupling in the plurality of resonator pillars.

5. The multilayer ceramic waveguide filter according to claim 4, characterized in that, The strip pattern is configured to be spaced apart from the outer peripheral surface of any one of the plurality of resonator pillars, so as to achieve capacitive coupling through the cross coupling.

6. The multilayer ceramic waveguide filter according to claim 4, characterized in that, Also includes: Multiple partitions are cut to a predetermined depth from the outer end to the inner side to divide multiple resonant blocks, each of which has a plurality of resonator pillars. The strip pattern is formed at the bridging end, which is sintered with ceramic material to divide any one of the plurality of partitions into two.

7. The multilayer ceramic waveguide filter according to claim 6, characterized in that, The bridging terminal is disposed between two adjacent ceramic layers when the plurality of ceramic layers are stacked.

8. The multilayer ceramic waveguide filter according to claim 2, characterized in that, The conductive metal pattern section also includes multiple resonator panels. The plurality of resonator panels are disposed between adjacent ceramic layers in the plurality of ceramic layers and have a predetermined diameter to cover the upper ends of the plurality of resonator pillars.

9. The multilayer ceramic waveguide filter according to claim 8, characterized in that, The plurality of resonator panels are integrally formed beneath a ceramic layer adjacent to the ceramic layer forming the plurality of resonator pillars.

10. The multilayer ceramic waveguide filter according to any one of claims 1 to 9, characterized in that, The plurality of ceramic layers consists of 13 layers stacked in the thickness direction; The plurality of resonator pillars are formed by at least a portion of them being formed through the thickness direction and then coated with a metal material.

11. The multilayer ceramic waveguide filter according to any one of claims 1 to 9, characterized in that, Also includes: A coupling adjustment post, formed by penetrating the plurality of ceramic layers in the thickness direction, is used to adjust the coupling amount of adjacent couplings through at least two adjacent resonator posts among the plurality of resonator posts.

12. The multilayer ceramic waveguide filter according to claim 4, characterized in that, The plurality of resonator posts are configured such that a first resonator post electrically connected to the input port, a fifth resonator post electrically connected to the output port, and a second, third, and fourth resonator post disposed between the first and fifth resonator posts are arranged at intervals. The signal input through the input port is transmitted sequentially from the first resonator post through the second, third, and fourth resonator posts to the fifth resonator post, and is output to the outside through the output port.

13. The multilayer ceramic waveguide filter according to claim 12, characterized in that, Adjacent couplings are sequentially achieved between the first resonator post and the second resonator post, and between the second resonator post and the third resonator post. Cross-coupling and inductive coupling are achieved between the third resonator post and the first resonator post, thereby forming an L-notch wave on the right side of the passband.

14. The multilayer ceramic waveguide filter according to claim 12, characterized in that, When coupling adjustment pillars, formed by penetrating the multiple ceramic layers in the thickness direction, are further disposed at the boundary locations of the first resonator pillar, the second resonator pillar, and the third resonator pillar, The coupling adjustment column adjusts the coupling amount of adjacent couplings.

15. The multilayer ceramic waveguide filter according to claim 12, characterized in that, When the strip pattern is arranged between the third resonator post and the fifth resonator post, capacitive coupling is achieved between the third resonator post and the fifth resonator post.

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