KR20210002052A - Waveguide resonator filter made with multiple substrates - Google Patents

Abstract

Disclosed is a resonator filter. The resonator filter includes: a first substrate having a flat square structure; a second substrate placed in a lower part of the first substrate, having first, second, third and fourth holes having a square structure, and including first through vias placed to surround the first to fourth holes entirely and second through vias placed on a partition dividing the first to fourth holes; and a third substrate placed in a lower part of the second substrate and including a first area where the second substrate is placed and a second area for input and output ports. The third substrate includes: an upper conductive thin film having fifth, sixth, seventh and eighth holes formed on positions corresponding to the first to fourth holes of the second substrate, respectively, and including first, second, third and fourth circular patches placed in the fifth to eighth holes respectively, and a conductor strip inducing the coupling of first polarity with the second and third circular patches; an insulator placed in a lower part of the upper conductive thin film and including first to fourth conductor pillars electrically connected with the first to fourth circular patches, first through vias placed along a part of the circumference of the first area, second through vias placed in a part of a position corresponding to the partition, and third through vias forming input and output ports in the second area; and a lower conductive thin film placed in a lower part of the insulator, having a square flat structure and having a part removed to form input and output ports. Therefore, the present invention is capable of facilitating the manufacture of a resonator filter.

Description

Waveguide resonator filter with a multilayer board structure {WAVEGUIDE RESONATOR FILTER MADE WITH MULTIPLE SUBSTRATES}

The present invention relates to a resonator filter, and more particularly, to a bandpass cavity resonator filter having a multilayer substrate structure.

In general, wireless communication systems and radars perform communication and detection functions using frequencies filtered by a bandpass filter. In general, a waveguide-type bandpass filter has a lower insertion loss and a high power handling performance than a planar filter. In addition, when a filter is designed using a dual mode waveguide resonator, the size of the filter can be reduced by two times compared to when a filter is designed using a single mode resonator. Another way to reduce the size of the filter is to design a filter using a waveguide resonator with a post inserted in the center.

Since the high-performance bandpass waveguide filter has a three-dimensional, non-planar structure, it is generally fabricated using a solid such as aluminum and then subjected to silver plating and then assembling. Therefore, there is a disadvantage in that a detailed manufacturing process of several steps is essential and the manufacturing period is long. In particular, for example, if there is a structure such as a post inside the resonator constituting the filter, and if there is an auxiliary structure to realize negative coupling, the number of manufacturing steps increases and the manufacturing period is long because manufacturing is not easy. Losing has a disadvantage. Another disadvantage is that since the input/output ports are generally formed of a coaxial connector, it is not compatible with a general printed circuit board (PCB).

S. Nam, B. Lee, B. Koh, C. Kwak, and J. Lee, "K-band fully reconfigurable pseudo-elliptic waveguide resonator filter with tunable positive and negative couplings," IEICE Transactions on Communications, vol. 99, pp. 2136-2145, Oct, 2016.

The problem to be solved by the present invention is to provide a resonator filter that is easy to manufacture and compatible with a printed circuit board.

In order to achieve the problem to be solved, the resonator filter according to embodiments of the present invention includes a first substrate having a rectangular plate-shaped structure, a first hole, a second hole, and a third having a quadrangular structure and disposed under the first substrate. A first through-via having a hole and a fourth hole and disposed to entirely surround the first through fourth holes, and a second through-via disposed in a partition wall separating the first through fourth holes. 2 substrate, and a third substrate disposed below the second substrate and including a first region in which the second substrate is disposed and a second region for input/output ports, wherein the third substrate is the second substrate A first circular patch having a fifth hole, a sixth hole, a seventh hole, and an eighth hole formed at positions corresponding to each of the first to fourth holes of, and disposed in each of the fifth to eighth holes , An upper conductive thin film including a second circular patch, a third circular patch, and a fourth circular patch, and a conductor strip for inducing a first polarity coupling to the second and third circular patches, and a lower portion of the upper conductive thin film First to fourth conductor pillars disposed at and electrically connected to the first to fourth circular patches, first through vias disposed along a portion of the edge of the first region, and a position corresponding to the partition wall The second through-vias disposed in a part of the insulator, the insulator including third through-vias constituting the input/output ports in the second region, and And a lower conductive thin film from which is removed.

According to embodiments of the present invention, by forming a conductor strip for forming a bonding structure of different polarity together when forming a circular patch of a post, it is easier to manufacture a resonator filter. In addition, since the input/output ports have a GCPW (grounded co-planar waveguide) structure, the resonator filter is compatible with the printed circuit board.

Detailed description of each drawing is provided in order to more fully understand the drawings cited in the detailed description of the present invention.
1 is an exploded perspective view illustrating a resonator filter according to an embodiment of the present invention.
2 is a perspective view illustrating a structure of a third substrate in the resonator filter shown in FIG. 1.
3 is a top view of the third substrate shown in FIG. 2.
4 is a bottom view of the third substrate shown in FIG. 2.
5 is a graph showing a resonator filter coupling diagram shown in FIG. 1.
6 is a graph showing simulation results of a resonator filter according to an embodiment of the present invention.
7 is a graph showing a measurement result of a resonator filter according to an embodiment of the present invention.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in the present specification are exemplified only for the purpose of describing the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention are It may be implemented in various forms and is not limited to the embodiments described herein.

Since the embodiments according to the concept of the present invention can apply various changes and have various forms, embodiments are illustrated in the drawings and will be described in detail in the present specification. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosed forms, and includes all changes, equivalents, or substitutes included in the spirit and scope of the present invention.

Terms such as first or second may be used to describe various elements, but the elements should not be limited by the terms. The terms are only for the purpose of distinguishing one component from other components, for example, without departing from the scope of the rights according to the concept of the present invention, the first component may be named as the second component and similarly the second component. The component may also be referred to as a first component.

When a component is referred to as being "connected" or "connected" to another component, it is understood that it is directly connected to or may be connected to the other component, but other components may exist in the middle. Should be. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in the middle. Other expressions describing the relationship between components, such as "between" and "directly between" or "adjacent to" and "directly adjacent to" should be interpreted as well.

Terms used in the present specification are used only to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprises" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described herein, but one or more other features. It is to be understood that the possibility of addition or presence of elements or numbers, steps, actions, components, parts, or combinations thereof is not preliminarily excluded.

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 belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this specification. Does not.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the scope of the patent application is not limited or limited by these embodiments. The same reference numerals in each drawing indicate the same members.

Hereinafter, a waveguide-type bandpass resonator filter will be described. Since the bandpass filter has a waveguide shape, insertion loss is lower than that of a planar filter and has high power handling performance. In addition, when a filter is designed using a dual mode waveguide resonator, the size of the filter can be reduced to 1/2 or less than when a filter is designed using a single mode waveguide resonator. In addition, when a waveguide resonator with a post inserted in the center is used, the size of the filter can be further reduced.

1 is an exploded perspective view for explaining a resonator filter according to an embodiment of the present invention, FIG. 2 is a perspective view for explaining the structure of a third substrate in the resonator filter shown in FIG. 1, and FIG. 3 is It is a top view of the shown third substrate, and FIG. 4 is a bottom view of the third substrate shown in FIG. 2.

1 to 4, the resonator filter 1000 may be composed of a plurality of vertically stacked substrates. According to an embodiment, the resonator filter 1000 may include a first substrate 100, a second substrate 200, and a third substrate 300.

The first substrate 100 is disposed on the top of the resonator filter 1000 and may have a square plate-shaped structure. As the first substrate 100, a commonly used conductor plate may be used. Depending on the embodiment, the first substrate 100 may be implemented using one surface of a general substrate as a conductor surface. For example, the first substrate 100 may include FR4 epoxy.

The second substrate 200 is disposed under the first substrate 100 and may have the same size and shape as the first substrate 100. In addition, the second substrate 200 may include the same FR4 epoxy as the first substrate 100. For example, the thickness of the second substrate 200 may be 0.2 mm.

According to an embodiment of the present invention, the second substrate 200 may include a plurality of holes for forming an air layer. In the present embodiment, a bandpass cavity resonator filter 1000 will be described, but a filter 1000 including four resonators and having a coupling structure having a different polarity will be exemplarily described. However, in the resonator filter 1000 of the present invention, the number of resonators and the number of coupling structures having different polarities are not limited thereto.

According to an embodiment, the second substrate 200 includes four holes, and each of the four holes may have a rectangular structure in a plan view. In addition, the four holes have the same size and may be spaced apart from each other. For example, when the second substrate 200 has a quadrangular structure, four holes may be disposed inside the second substrate 200 to have a predetermined separation distance. Hereinafter, for ease of description, each of the four holes is referred to as a first hole HL1, a second hole HL2, a third hole HL3, and a fourth hole HL4.

The first hole HL1, the second hole HL2, the third hole HL3, and the fourth hole HL4 of the second substrate 200 may be separated by a partition wall. According to an embodiment, a part of the partition wall separating the second hole HL2 and the third hole HL3 is removed, so that the second hole HL2 and the third hole HL3 may have a structure in communication with each other. .

In the second substrate 200, first through vias TV1 disposed to completely surround the first hole HL1, the second hole HL2, the third hole HL3, and the fourth hole HL4. And, second through vias TV2 formed in the partition wall may be provided. Each of the first through vias TV1 and the second through vias TV2 has a structure penetrating the second substrate 200, and the first substrate 100 and the third substrate ( 300) can be electrically connected to each other. The first through vias TV1 are spaced apart from each other by a first separation distance, but since the gap is narrow, it will be described that they are continuously disposed. The second through vias TV2 may be continuously disposed, and may be spaced apart by a second separation distance greater than the first separation distance in the partition wall separating the second hole HL2 and the third hole HL3. A passage PT may be formed in a partition wall separating the second hole HL2 and the third hole HL3 by second through vias TV2 spaced apart from each other.

The vias or via holes described in the present specification are holes having a cylindrical structure and may be formed by plating an inner surface of the hole with a conductive material. The conductive material may include copper, brass, silver, gold, and the like, but it is obvious that the scope of the present invention is not limited to the type of conductive material.

The third substrate 300 may have a larger size than the second substrate 200. According to an embodiment, the third substrate 300 may include a first area AR1 for resonators and a second area AR2 for input/output ports P_In and P_Out. For example, the second substrate 200 may be disposed to cover the first area AR1 of the third substrate 300.

The third substrate 300 may include an upper conductive thin film 310, an insulator 320, and a lower conductive thin film 330.

Four holes are formed in the upper conductive thin film 310, and each of the four holes may be formed in the same size and shape at positions corresponding to the four holes of the second substrate 200. In addition, the upper conductive thin film 310 may have a partition wall having the same size and shape at a position corresponding to the partition wall of the second substrate 200. For ease of description, each of the four holes of the upper conductive thin film 310 is referred to as a fifth hole HL5, a sixth hole HL6, a seventh hole HL7, and an eighth hole HL8. As in the second substrate 200, in the upper conductive thin film 310, a part of the partition wall between the sixth hole HL6 and the seventh hole HL7 is removed, so that the sixth hole HL6 and the seventh hole HL7 are formed. Can communicate with each other. Accordingly, the passage PT may be formed in portions of the sixth hole HL6 and the seventh hole HL7 among the partition walls of the upper conductive thin film 310.

The upper conductive thin film 310 may include circular patches and a conductor strip (CS). The circular patches include a first circular patch CP1 and a second circular patch disposed at the centers of each of the fifth hole HL5, the sixth hole HL6, the seventh hole HL7, and the eighth hole HL8. CP2), a third circular patch CP3, and a fourth circular patch CP4. The conductor strip CS includes a first portion having a curvature to surround a part of the second circular patch CP2, and a second portion extending from the first portion and crossing the sixth hole HL6 and the seventh hole HL7. A portion and a third portion extending from the second portion and having a curvature to surround a portion of the third circular patch CP3 may be included. For example, the conductor strip CS may have an "S" shape in plan view.

According to an embodiment, in the upper conductive thin film 310, the conductor strip CS is formed together while forming circular patches, so that the resonator filter 1000 can be easily manufactured.

The insulator 320 may include a thermoset microwave material (TMM).

The insulator 320 includes conductive posts electrically connected to the first to fourth circular patches CP1, CP2, CP3, and CP4, and a third disposed along the edge of the first area AR1. The through vias TV3, the fourth through vias TV4 disposed at positions corresponding to the partition wall of the upper conductive thin film 310 in the first region AR1, and the input/output port P_Out in the second region AR2 It may include fifth through vias TV5 constituting ). At this time, the conductor pillars, the third through vias TV3, the fourth through vias TV4, and the fifth through vias TV5 each pass through the insulator 320 to form the upper conductive thin film 310 and the lower part. The conductive thin films 330 may be electrically connected.

The conductor pillars are arranged along the edge of the first circular patch CP1 at a position corresponding to the first circular patch CP1, so that the plurality of first conductor pillars P1 and the first conductor pillars P1 having a ring structure in a plan view 2 In a position corresponding to the circular patch CP2, the plurality of second conductor pillars P2 and the third circular patch CP3 are arranged along the edge of the second circular patch CP2 and have a ring structure in a plan view. A plurality of third conductor pillars P3 having a ring structure in a plan view by being disposed along the edge of the third circular patch CP3 at a corresponding position, and a fourth at a position corresponding to the fourth circular patch CP4. It may include a plurality of fourth conductor pillars P4 arranged along the edge of the circular patch CP4 and having a ring structure in a plan view.

Accordingly, a first post including a first circular patch CP1 and first conductor pillars P1, a second post including a second circular patch CP2 and second conductor pillars P2, A third post including a third circular patch CP3 and third conductor pillars P3, and a fourth post including a fourth circular patch CP4 and fourth conductor pillars P4 may be formed. have. In this embodiment, a filter 1000 having posts in each of the cavity resonators is described, but the present invention is also applicable to a filter 1000 without posts.

The first area AR1 of the insulator 320 is a first portion PAT1 corresponding to the fifth hole HL5 and a second portion PAT2 corresponding to the sixth hole HL6 in the upper conductive thin film 310. , A third portion PAT3 corresponding to the seventh hole HL7 and a fourth portion PAT4 corresponding to the eighth hole HL8.

The third through vias TV3 cover the first portion PAT1, the second portion PAT2, the third portion PAT3, and the fourth portion PAT4 of the first area AR1 of the insulator 320. It is disposed along the edge of the first region AR1 so as to surround it, and the third through vias TV3 are spaced apart from the first part PAT1 to form a first passage, and are spaced apart from the fourth part PAT4 again. A second passage can be formed. The first passage and the second passage are for input/output ports P_In and P_Out, and for ease of explanation, it will be described that the first passage is composed of an input port P_In and the second passage is composed of an output port P_Out. . The opposite is also possible.

The fourth through vias TV4 are disposed to be spaced apart from each other to define a third passage in a partition wall separating the first portion PAT1 and the second portion PAT2, and the second portion PAT2 and the third portion PAT3 ) Are spaced apart from each other to define a fourth passage, and are spaced apart to define a fifth passage in the partition wall separating the third portion (PAT3) and the fourth portion (PAT4), and the fourth portion ( PAT4) and the first portion PAT1 may be spaced apart from each other to define a sixth passage in the partition wall. In this case, the above-described conductor strip CS may be disposed in the fifth passage.

The fifth through-vias TV5 are disposed in the second area AR2 and may be disposed to extend from the third through-vias TV3. According to an embodiment, the input port P_In is formed by the third through-vias TV3 extending from both ends of the first passage defined by the third through-vias TV3 to the end of the insulator 320 Can be. In addition, the output port P_Out may be formed by third through vias TV3 extending from both ends of the second passage defined by the third through vias TV3 to the end of the insulator 320.

The lower conductive thin film 330 has a rectangular plate-like structure, and a portion of the lower conductive thin film 330 may be removed from an end portion of the first region AR1 to correspond to the input port P_In and the output port P_Out of the insulator 320. The lower conductive thin film 330 is disposed immediately adjacent to the third through vias TV3 constituting the input port P_In, is parallel to each other, and crosses from the first region AR1 to the second region AR2. 1 The first removal portion RMP1 surrounding a part of the conductor pillars P1 and the third through-vias TV3 constituting the output port P_Out are disposed immediately adjacent to each other and are parallel to each other, and the first area AR1 ) May have a second removal portion RMP2 that crosses the second region AR2 and surrounds a portion of the second conductor pillars P2. This structure is called GCPW (grounded co-planar waveguide).

As described above, since the resonator filter 1000 constitutes input/output ports of the GCPW structure, the resonator filter 1000 can be mounted on a printed circuit board and used, thereby having compatibility with the printed circuit board. In addition, in the case of using a connector such as a coaxial connector, it is possible to measure using a measuring instrument or connect it to another circuit to which the connector is attached, so that the usability may be further improved. That is, according to the present invention, it is possible to provide a waveguide resonator filter structure compatible with a printed circuit board (PCB) and capable of connecting a connector.

The resonator filter 1000 according to an exemplary embodiment of the present invention includes a first conductor pillar P1, a first circular patch CP1, and a first hole HL1 of the second substrate 200. A second resonator including a resonator, second conductor pillars P2, a second circular patch CP2, and a second hole HL2 of the second substrate 200, and third conductor pillars P3 , A third circular patch CP3, and a third resonator including a third hole HL3 of the second substrate 200, fourth conductor pillars P4, a fourth circular patch CP4, and 2 It may include a fourth resonator including a fourth hole HL4 of the substrate 200.

5 is a graph showing a resonator filter coupling diagram shown in FIG. 1.

In FIG. 5, each of the input port and the output port is denoted by "S" and "L", and numbers represent resonators. That is, "1" represents a first resonator, "2" represents a second resonator, "3" represents a third resonator, and "4" represents a fourth resonator, respectively.

Referring to FIGS. 1 and 5, the conductor strip CS may be disposed between the second resonator and the third resonator to form a coupling structure having a polarity different from that of the other resonators. For example, when a negative coupling structure is formed in the conductor strip CS, a negative coupling is formed between the second resonator and the third resonator, and the remaining resonators, that is, the first and second resonators, and the third and third resonators. A positive coupling structure may be formed between the 4 resonators and the first and fourth resonators, respectively. That is, a solid line represents a positive bond and a dotted line represents a negative bond. The opposite is also possible.

6 is a graph showing simulation results of a resonator filter according to an embodiment of the present invention.

6 shows a case where the center frequency is 5 GHz and the bandwidth is 300 MHz in the resonator filter according to an embodiment of the present invention. It can be seen that a pair of transmission zeros are formed due to the negative coupling structure formed between the second and third resonators.

7 is a graph showing a measurement result of a resonator filter according to an embodiment of the present invention.

Referring to FIG. 7, it can be seen that the simulation results of FIG. 6 are similar. That is, it can be seen that a pair of transmission zero points are formed in the actual measurement result by the negative coupling structure formed between the second and third resonators.

In the above, embodiments of the present invention have been described with reference to the accompanying drawings, but those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features. You can understand that there is. Therefore, it should be understood that the embodiments described above are illustrative in all respects and are not limiting.

The present invention has been described with reference to the embodiments shown in the drawings, but these are only exemplary, and those of ordinary skill in the art will appreciate that various modifications and other equivalent embodiments are possible therefrom. For example, the described techniques are performed in a different order from the described method, and/or components such as systems, structures, devices, and circuits described are combined or combined in a form different from the described method, or other components Alternatively, even if substituted or substituted by an equivalent, an appropriate result can be achieved. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the attached registration claims.

1000: resonator filter
100: first substrate
200: second substrate
300: third substrate
310: lower conductive thin film
320: insulator
330: upper conductive thin film
RMP1, RMP2: removed part
CS: Conductor strip

Claims (6)

A first substrate having a rectangular plate-shaped structure;
First through vias disposed under the first substrate, having a first hole, a second hole, a third hole, and a fourth hole having a rectangular structure, and disposed to completely surround the first to fourth holes And a second substrate including second through vias disposed in a partition wall separating the first to fourth holes. And
A third substrate disposed under the second substrate and including a first region in which the second substrate is disposed and a second region for input/output ports,
The third substrate,
The second substrate has a fifth hole, a sixth hole, a seventh hole, and an eighth hole formed at positions corresponding to each of the first to fourth holes, and is disposed in each of the fifth to eighth holes. An upper conductive thin film including a first circular patch, a second circular patch, a third circular patch, a fourth circular patch, and a conductor strip for inducing coupling of a first polarity to the second and third circular patches;
First to fourth conductor pillars disposed under the upper conductive thin film and electrically connected to the first to fourth circular patches, first through vias disposed along a portion of the edge of the first region, the An insulator including second through vias disposed at a portion of a position corresponding to the partition wall, and third through vias constituting the input/output ports in the second region; And
A resonator filter comprising a lower conductive thin film disposed under the insulator and having a rectangular plate-shaped structure and partially removed to constitute the input/output port.
The method of claim 1,
A bonding structure of a first polarity is defined between the second and third circular patches in the conductor strip,
A resonator filter in which a coupling structure having a second polarity opposite to the first polarity is defined between the first and second circular patches, the third and fourth circular patches, and the first and fourth circular patches .
The method of claim 1,
A first resonator including the first hole, the first circular patch, and the first conductive pillars, a second resonator including the second hole, the second circular patch, and the second conductive pillars, A third resonator including the third hole, the third circular patch, and the third conductive pillars, and a fourth resonator including the fourth hole, the fourth circular patch, and the fourth conductive pillars Constructing resonator filter.
The method of claim 1,
Each of the first and second substrates includes FR4 epoxy,
The insulator is a resonator filter including a thermoset microwave material (TMM).
The method of claim 1,
The conductor strip is a resonator filter formed together when forming the first to fourth circular patches.
The method of claim 1,
The lower conductive thin film is a resonator filter having a GCPW (grounded co-planar waveguide) structure.

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