Resonator filter

Abstract

This application proposes a resonant filter. The resonant filter includes: a housing, multiple metal resonators, an input port, and an output port. The housing has a accommodating cavity and a first inner surface and a second inner surface disposed opposite each other, and is provided with a first through hole and a second through hole communicating with the accommodating cavity. The multiple metal resonators are located in the accommodating cavity and disposed on the first inner surface and the second inner surface. The multiple metal resonators are substantially located on the same plane and are distributed in opposite directions, and coupling is generated between the multiple metal resonators to form a signal connection. The input port is connected to the first through hole and is connected to one of the multiple metal resonators. The output port is connected to the second through hole and is connected to another of the multiple metal resonators. Therefore, a flat design of the resonant filter is achieved.

Description

Technical Field

[0001] This application relates to the field of filter technology, and in particular to a resonant filter. Prior Technology

[0002] A filter is a frequency selective device used to filter out unwanted frequency band signals (i.e., attenuate signals outside the frequency band) and leave signals in the useful frequency band (i.e., allow signals within the frequency band to pass through).

[0003] Existing resonant filters mainly consist of a housing with a cavity and an opening, a cover plate over the opening, and resonant components disposed within the cavity. These resonant components are typically arranged in multiple rows and include bent components, multiple metal resonant plates, and combinations thereof. The multi-row arrangement of resonant components occupies a large space within the cavity, which is detrimental to the miniaturization design of the resonant filter; resonant components including bent components present challenges in processing and dimensional accuracy.

[0004] Therefore, there is an urgent need to provide a resonant filter to solve the above problems. Summary of the Invention

[0005] This application provides a resonant filter that solves the problems of existing resonant filters, such as the multi-row arrangement of resonant components, which is not conducive to the miniaturization design of the resonant filter, and the high processing difficulty and low dimensional accuracy of existing resonant filters due to the inclusion of bent components.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows:

[0007] This application provides a resonant filter, comprising: a housing, a plurality of metal resonators, an input port, and an output port. The housing has a accommodating cavity and a first inner surface and a second inner surface disposed opposite to each other, and is provided with a first through hole and a second through hole communicating with the accommodating cavity. The plurality of metal resonators are located in the accommodating cavity and disposed on the first inner surface and the second inner surface. The plurality of metal resonators are substantially located on the same plane and are distributed in opposite directions. The plurality of metal resonators are coupled to form a signal connection. The input port is connected to the first through hole and is connected to one of the plurality of metal resonators. The output port is connected to the second through hole and is connected to another of the plurality of metal resonators.

[0008] In the resonant filter of this application embodiment, multiple metal resonators do not need to be bent, which has the advantage of simple processing; multiple metal resonators are actually located on the same plane and are distributed in opposite directions, realizing the flat design of the resonant filter (that is, the length of the resonant filter along the direction perpendicular to the arrangement direction of multiple metal resonators is significantly reduced), which is conducive to the miniaturization of the resonant filter; adjacent two metal resonators are coupled to form a signal connection, which does not require the design of bending parts, so there are no problems of high processing difficulty and low dimensional accuracy. Simple Explanation of the Diagram

[0009] The drawings illustrated herein are provided to further illustrate this application and form part of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0010] Figure 1 is a perspective view of an embodiment of a resonant filter according to this application;

[0011] Figure 2 is an exploded view of an embodiment of the resonant filter in Figure 1;

[0012] Figure 3 is a cross-sectional schematic diagram of the resonant filter in Figure 2;

[0013] Figure 4 is a perspective view of another embodiment of the resonant filter according to this application;

[0014] Figure 5 is an exploded view of an embodiment of the resonant filter in Figure 4;

[0015] Figure 6 is a cross-sectional schematic diagram of the resonant filter in Figure 5;

[0016] Figure 7 is an exploded view of another embodiment of the resonant filter in Figure 1;

[0017] Figure 8 is a cross-sectional schematic diagram of the resonant filter in Figure 7;

[0018] Figure 9 shows the frequency band insertion loss curves of the resonant filter in Figure 3 and the resonant filter in Figure 8;

[0019] Figure 10 is a perspective view of yet another embodiment of the resonant filter according to this application;

[0020] Figure 11 is an exploded view of an embodiment of the resonant filter in Figure 10;

[0021] Figure 12 is a cross-sectional schematic diagram of the resonant filter in Figure 11;

[0022] Figure 13 is an exploded view of another embodiment of the resonant filter in Figure 10; and

[0023] Figure 14 is a cross-sectional schematic diagram of the resonant filter in Figure 13. Implementation

[0024] The embodiments of the present invention will be described below with reference to the accompanying drawings. In these drawings, the same reference numerals denote the same or similar components or method flows.

[0025] It must be understood that the use of terms such as "comprising" or "including" in this specification is intended to indicate the presence of specific technical features, values, method steps, work processes, components and / or components, but does not preclude the addition of more technical features, values, method steps, work processes, components, or any combination thereof.

[0026] It is important to understand that when a component is described as "connected" or "coupled" to another component, it can be a direct connection or coupling to other components, and there may be intermediate components. Conversely, when a component is described as "directly connected" or "directly coupled" to another component, there are no intermediate components.

[0027] In addition, although the terms "first," "second," etc. are used in this article to describe different components, these terms are only used to distinguish components or operations described with the same technical terms.

[0028] Please refer to Figures 1 to 3. Figure 1 is a perspective view of an embodiment of the resonant filter according to this application, Figure 2 is an exploded view of an embodiment of the resonant filter of Figure 1, and Figure 3 is a cross-sectional view of the resonant filter of Figure 2. As shown in Figures 1 to 3, the resonant filter 100 is applicable to frequency bands above 5.5 GHz and includes: a housing 110, a plurality of metal resonators 120, an input port 130, and an output port 140. The housing 110 has a cavity 111 and a first inner surface 112 and a second inner surface 113 disposed opposite to each other, and is provided with a first through hole 114 and a second through hole 115 communicating with the cavity 111; the plurality of metal resonators 120 are located in the cavity 111 and disposed in... On the first inner surface 112 and the second inner surface 113 (i.e., multiple metal resonators 120 are arranged in two rows), the multiple metal resonators 120 are substantially located on the same plane and are arranged opposite each other, and the multiple metal resonators 120 are coupled to form a signal connection; the input port 130 is connected to the first through hole 114 and is connected to one of the multiple metal resonators 120; the output port 140 is connected to the second through hole 115 and is connected to another of the multiple metal resonators 120.

[0029] Each of the multiple metal resonators 120 can be, but is not limited to, a sheet with a metal surface or a metal plate. Therefore, the multiple metal resonators 120 do not require bending, which has the advantage of simple processing. Since the multiple metal resonators 120 are substantially located on the same plane and are distributed in opposite directions, the flattened design of the resonant filter 100 is achieved (i.e., the length of the resonant filter 100 along the first direction F is significantly reduced, and the first direction F is perpendicular to the arrangement direction C of the multiple metal resonators 120), which is beneficial to the miniaturization of the resonant filter 100. In addition, the coupling between two adjacent metal resonators 120 forms a signal connection, eliminating the need for bending components and thus avoiding problems such as high processing difficulty and low dimensional accuracy. Furthermore, the thickness of the metal resonators 120 can be, but is not limited to, 0.5 mm to 3 mm. The thickness of each metal resonator 120 is usually consistent. If it is inconsistent, the thickness difference can be, but is not limited to, less than 50%. The thickness of the metal resonators 120 is related to the size and performance requirements of the resonant filter 100. Furthermore, the shape of the metal resonator 120 can be designed according to its frequency and coupling requirements with adjacent metal resonators 120, while ensuring that the size is as small as possible. In addition, multiple metal resonators 120 can be fixed on the first inner surface 112 or the second inner surface 113 by laser soldering, solder paste soldering or brazing.

[0030] In one embodiment, the material of the plurality of metal resonators 120 may be, but is not limited to, iron or iron alloy, and the processing method may be, but is not limited to, laser cutting, wire cutting, or sheet metal stamping.

[0031] In one embodiment, a plurality of metal resonators 120 may be alternately arranged on the first inner surface 112 and the second inner surface 113.

[0032] In one embodiment, each of the plurality of metal resonators 120 may include an upright segment 121, an extension segment 123 extending from one end of the upright segment 121, and a coupling segment 125 extending from the end of the extension segment 123 away from the upright segment 121. The end of the upright segment 121 away from the extension segment 123 is fixed to a first inner surface 112 or a second inner surface 113. The coupling segment 125 of each of the plurality of metal resonators 120 is close to the coupling segment 125 of an adjacent metal resonator 120. Adjacent metal resonators 120 may be two metal resonators 120 arranged opposite each other or two metal resonators 120 arranged along the arrangement direction C.

[0033] In one embodiment, the plurality of metal resonators 120 are not physically connected. In one example, the plurality of metal resonators 120 fixed on the first inner surface 112 are spaced apart, and the plurality of metal resonators 120 fixed on the second inner surface 113 are spaced apart; the spacing between two adjacent metal resonators 120 fixed on the first inner surface 112 and the second inner surface 113 is related to the size and performance requirements of the resonant filter 100.

[0034] In one embodiment, the outer casing 110 is further provided with a plurality of partitions 116, which divide the accommodating cavity 111 into a plurality of resonant cavities 117 arranged in two rows. A plurality of metal resonant plates 120 are disposed within the plurality of resonant cavities 117, and two adjacent opposing resonant cavities 117 are connected. Specifically, adjacent upper and lower rows of resonant cavities 117 are connected, and since a plurality of metal resonant plates 120 are disposed within a plurality of resonant cavities 117, coupling can be generated between two opposing metal resonant plates 120 to form a signal connection. A resonant cavity 117 may be provided with one or more metal resonant plates 120, and the number and corresponding arrangement of resonant cavities 117 and metal resonant plates 120 can be designed according to actual needs.

[0035] In one embodiment, the outer casing 110 may include a base plate 118, a housing 119, and a cover plate 127. The housing 119 has a first opening 1191 and a second opening 1192 disposed opposite to each other. The base plate 118 is disposed at the first opening 1191, and the cover plate 127 is disposed at the second opening 1192. The base plate 118, housing 119, and cover plate 127 surround to form an accommodating cavity 111. The base plate 118 has a first inner surface 112, and the cover plate 127 has a second inner surface 113. The base plate 118, housing 119, and cover plate 127 may be made of, but are not limited to, aluminum or aluminum alloy. The housing 119 may be manufactured by, but is not limited to, computer numerical control (CNC) machine tools, die casting, or extrusion molding.

[0036] In one embodiment, a first through hole 114 and a second through hole 115 are disposed on a base plate 118 or a cover plate 127. The input port 130 includes a first support base 132. A metal resonator 120 connected to the input port 130 passes through the first support base 132 via a first tap 120a and extends out of the outer shell 110. The first tap 120a and the metal resonator 120 connected to the input port 130 are integrally formed. The output port 140 includes a second support base 142. A metal resonator 120 connected to the output port 140 passes through the second support base 142 via a second tap 120b and extends out of the outer shell 110. The second tap 120b and the metal resonator 120 connected to the output port 140 are integrally formed. The first support 132 and the second support 142 can be made of engineering plastics, such as polytetrafluoroethylene (PTFE), perfluoropropyl vinyl ether (PFA), and polyphenylene sulfide (PPS). The processing methods of the first support 132 and the second support 142 can be, but are not limited to, CNC machining, injection molding, and powder sintering. The first support 132 and the second support 142 can be joined by an adhesive to the first through hole 114 and the second through hole 115. The first tap 120a is used to feed the signal into the resonant filter 100. The second tap 120b is used to feed the signal out of the resonant filter 100. The number of the first tap 120a and the second tap 120b is related to the number of channels of the resonant filter 100. In this embodiment, the resonant filter 100 is a single-channel filter. Therefore, the number of the first tap 120a and the second tap 120b is one.

[0037] Please refer to Figures 4 to 6. Figure 4 is a perspective view of another embodiment of the resonant filter according to this application, Figure 5 is an exploded view of an embodiment of the resonant filter of Figure 4, and Figure 6 is a cross-sectional view of the resonant filter of Figure 5. As shown in Figures 4 to 6, it can be seen that the difference between the embodiments of Figures 4 to 6 and the embodiments of Figures 1 to 3 lies in the placement of the first through hole 114 and the second through hole 115, as well as the design of the input port 130 and the output port 140. In Figures 4 to 6, the first through hole 114 and the second through hole 115 can be disposed on the same side wall of the housing 119. The same side wall can be the side wall 1193 of the housing 119 parallel to the arrangement direction C of the metal resonator 120. The input port 130 can include a first port conductor 134 and a first base 136. One end of the first port conductor 134 is connected to a metal resonator 120. The first base 136 is engaged with the first through hole 114. The other end of the first port conductor 134 passes through the first base 136 and extends out of the housing 110. The output port 140 can include a second port conductor 144 and a second base 146. One end of the second port conductor 144 is connected to another metal resonator 120. The second base 146 is engaged with the second through hole 115. The other end of the second port conductor 144 passes through the second base 146 and extends out of the housing 110. The first base 136 and the second base 146 may be made of, but are not limited to, engineering plastics; the processing methods of the first base 136 and the second base 146 may be, but are not limited to, CNC machining, injection molding, and powder sintering; the first base 136 and the second base 146 may be joined by an adhesive to the first through hole 114 and the second through hole 115; the first port conductor 134 is used to feed the signal into the resonant filter 100; the second port conductor 144 is used to feed the signal out of the resonant filter 100; the number of input ports 130 and output ports 140 is related to the number of channels of the resonant filter 100. In this embodiment, the resonant filter 100 is a single-channel filter, therefore, the number of input ports 130 and output ports 140 is one each.

[0038] In one embodiment, the first through hole 114 and the second through hole 115 can be disposed on different side walls of the housing 119. These different side walls can be two corresponding side walls of the housing 119 parallel to the arrangement direction C of the metal resonator 120. The input port 130 may include a first port conductor 134 and a first base 136. One end of the first port conductor 134 is connected to a metal resonator 120, the first base 136 is engaged with the first through hole 114, and the other end of the first port conductor 134 extends out of the housing 110 after passing through the first base 136. The output port 140 may include a second port conductor 144 and a second base 146. One end of the second port conductor 144 is connected to another metal resonator 120, the second base 146 is engaged with the second through hole 115, and the other end of the second port conductor 144 extends out of the housing 110 after passing through the second base 146. In other words, the placement of the input port 130 and the output port 140 is more flexible and can adapt to different design requirements.

[0039] Please refer to Figures 1 to 3. The plurality of metal resonators 120 include a first resonator 122, a second resonator 124, a third resonator 126 and a fourth resonator 128 connected in sequence. The first resonator 122 and the fourth resonator 128 are spaced apart on the second inner surface 113, and the second resonator 124 and the third resonator 126 are spaced apart on the first inner surface 112. The first resonator 122 and the fourth resonator 128 are located in different resonant cavities 117, and the second resonator 124 and the third resonator 126 are located in the same resonant cavity 117. The signal transmission path is sequentially formed by the first resonator 122, the second resonator 124, the third resonator 126, and the fourth resonator 128. Each time the signal passes through a metal resonator 120, its phase changes by -90°. Inductive coupling can occur between the first resonator 122 and the second resonator 124, between the second resonator 124 and the third resonator 126, and between the third resonator 126 and the fourth resonator 128. This inductive coupling enhances the high-frequency suppression of the resonant filter 100. The coupling between the first resonator 122 and the third resonator 126, and between the second resonator 124 and the fourth resonator 128, is extremely small; therefore, it does not affect the implementation of the resonant filter 100.

[0040] In one embodiment, the input port 130 and the output port 140 are respectively connected to the first resonant plate 122 and the fourth resonant plate 128.

[0041] Please refer to Figures 7 and 8. Figure 7 is an exploded view of another embodiment of the resonant filter of Figure 1, and Figure 8 is a cross-sectional view of the resonant filter of Figure 7. As shown in Figures 7 and 8, it can be seen that the difference between the embodiments of Figures 7 and 8 and the embodiments of Figures 1 to 3 is that the first resonant plate 122 and the fourth resonant plate 128 are disposed in different resonant cavities 117 that are interconnected, and capacitive cross-coupling can be generated between the first resonant plate 122 and the fourth resonant plate 128.

[0042] Please refer to Figures 3, 8, and 9. Figure 9 shows the frequency band insertion loss curves of the resonant filter in Figure 3 and the resonant filter in Figure 8. In Figure 9, the horizontal axis is the frequency in megahertz (MHz); the vertical axis is the insertion loss in decibels (dB). The solid line is the frequency band insertion loss curve of the resonant filter 100 (i.e., the resonant filter 100 in Figure 8) when the first resonant plate 122 and the fourth resonant plate 128 are located in different resonant cavities 117 that are interconnected. The dashed line is the frequency band insertion loss curve of the resonant filter 100 (i.e., the resonant filter 100 in Figure 3) when the first resonant plate 122 and the fourth resonant plate 128 are located in their own independent resonant cavities 117. As shown in Figure 9, when the first resonator 122 and the fourth resonator 128 are located in their respective independent resonant cavities 117, the first resonator 122 and the fourth resonator 128 are blocked by the partition 116 and no cross-coupling occurs. As a result, the out-of-band signal suppression capability of the resonant filter 100 is relatively poor (slow attenuation). When the first resonator 122 and the fourth resonator 128 are located in different resonant cavities 117 that are interconnected, capacitive cross-coupling can occur between the first resonator 122 and the fourth resonator 128, causing the signal phase to change by +90°. Symmetrical zeros are achieved on both sides of the insertion loss curve of the resonant filter 100 (i.e., capacitive zeros are generated on the left side of the frequency band to enhance the low-frequency suppression of the resonant filter 100; and inductive zeros are generated on the right side of the frequency band to enhance the high-frequency suppression of the resonant filter 100), thereby significantly increasing the out-of-band signal suppression capability of the resonant filter 100.

[0043] In one embodiment, when the first resonant element 122 and the fourth resonant element 128 are disposed in different resonant cavities 117 that are interconnected, the resonant filter 100 may further include a first connecting rib 150. The first connecting rib 150 and the first resonant element 122 are substantially located on the same plane, and the first connecting rib 150 connects the first resonant element 122 and the fourth resonant element 128 (as shown in FIG8). The first connecting rib 150, the first resonant element 122, and the fourth resonant element 128 may be, but are not limited to, integrally formed. The first connecting rib 150 is used to enhance the amount of capacitive cross-coupling generated between the first resonant element 122 and the fourth resonant element 128.

[0044] In one embodiment, the resonant filter 100 may further include a second connecting rib 160, which is substantially located on the same plane as the second resonant plate 124. The second connecting rib 160 connects the second resonant plate 124 and the third resonant plate 126 (as shown in FIG8). The second connecting rib 160, the second resonant plate 124, and the third resonant plate 126 may be, but are not limited to, integrally formed. The second connecting rib 160 is used to enhance the electromagnetic coupling between the second resonant plate 124 and the third resonant plate 126.

[0045] In one embodiment, when other factors remain constant, the smaller the distance between the end of the second resonant plate 124 away from the first inner surface 112 and the end of the third resonant plate 126 away from the first inner surface 112 (i.e., the smaller the distance between the coupling segment 125 of the second resonant plate 124 and the coupling segment 125 of the third resonant plate 126), the smaller the distance between the second connecting rib 160 and the first inner surface 112; the larger the distance between the end of the second resonant plate 124 away from the first inner surface 112 and the end of the third resonant plate 126 away from the first inner surface 112 (i.e., the larger the distance between the coupling segment 125 of the second resonant plate 124 and the coupling segment 125 of the third resonant plate 126), the larger the distance between the second connecting rib 160 and the first inner surface 112. The larger the distance between the second connecting rib 160 and the first inner surface 112, the stronger the coupling effect between the second resonant plate 124 and the third resonant plate 126.

[0046] Please refer to Figures 10 to 12. Figure 10 is a perspective view of another embodiment of the resonant filter according to this application, Figure 11 is an exploded view of an embodiment of the resonant filter of Figure 10, and Figure 12 is a cross-sectional view of the resonant filter of Figure 11. As shown in Figures 10 to 12, the first resonant plate 122, the second resonant plate 124, the third resonant plate 126, and the fourth resonant plate 128 can constitute a set of resonant plates 129. These metal resonant plates 120 can include N sets of resonant plates 129 and N-1 intermediate resonant plates 170. An intermediate resonant plate 170 is disposed between two adjacent sets of resonant plates 129, where N is an integer greater than or equal to 2. Each of the N-1 intermediate resonant plates 170 is disposed on the first inner surface 112 or the second inner surface 113 and is coupled with the fourth resonant plate 128 and the first resonant plate 122 adjacent to both sides (i.e., the fourth resonant plate 128 of the previous set of resonant plates 129 and the first resonant plate 122 of the next set of resonant plates 129, the previous set of resonant plates 129 and the next set of resonant plates 129 are defined by the order of signal transmission) to form a signal connection. In this embodiment, N can be, but is not limited to, 2. Therefore, the resonant filter 100 includes two sets of resonant plates 129 and an intermediate resonant plate 170. The intermediate resonant plate 170 can be disposed on the first inner surface 112. Because the resonant filter 100 includes two sets of resonant plates 129, it can generate two capacitive zeros and two inductive zeros. It should be noted that the intermediate resonant plate 170 will not couple with the third resonant plate 126 of the previous set of resonant plates 129 and the second resonant plate 124 of the subsequent set of resonant plates 129. Therefore, the intermediate resonant plate 170 can be disposed on the first inner surface 112 or the second inner surface 113.

[0047] In one embodiment, input port 130 and output port 140 are respectively connected to the first resonator 122 of the first group of resonators 129 and the fourth resonator 128 of the Nth group of resonators 129. For example, referring to FIG12, input port 130 and output port 140 are respectively connected to the first resonator 122 of the first group of resonators 129 (i.e., the leftmost group of resonators 129 in FIG12) and the fourth resonator 128 of the second group of resonators 129 (i.e., the rightmost group of resonators 129 in FIG12). Therefore, the signal transmission path is sequentially the first resonator 122, the second resonator 124, the third resonator 126 and the fourth resonator 128 of the first group of resonators 129, the intermediate resonator 170, and the first resonator 122, the second resonator 124, the third resonator 126 and the fourth resonator 128 of the second group of resonators 129.

[0048] In one embodiment, the intermediate resonant plate 170 disposed on the second inner surface 113, the fourth resonant plate 128 and the first resonant plate 122 adjacent to its two sides are disposed in the same resonant cavity 117.

[0049] Please refer to Figures 10, 13, and 14. Figure 13 is an exploded view of another embodiment of the resonant filter of Figure 10, and Figure 14 is a cross-sectional view of the resonant filter of Figure 13. As shown in Figures 13 and 14, the difference between the embodiments of Figures 13 and 14 and the embodiments of Figures 11 and 12 is that the intermediate resonant plate 170 of Figures 13 and 14 is disposed on the first inner surface 112. The intermediate resonant plate 170 disposed on the first inner surface 112 is disposed in a different resonant cavity 117 from the adjacent second resonant plate 124 and third resonant plate 126 (i.e., the third resonant plate 126 of the previous group of resonant plates 129 and the second resonant plate 124 of the next group of resonant plates 129).

[0050] In summary, in the resonant filter of this application embodiment, multiple metal resonators do not require bending, offering the advantage of simple processing. Since the multiple metal resonators are essentially located on the same plane and arranged in opposite directions, the length of the resonant filter along the direction perpendicular to the arrangement of the multiple metal resonators is significantly reduced, which is beneficial for the miniaturization of the resonant filter. Adjacent metal resonators are coupled to form a signal connection, eliminating the need for bending components and thus avoiding problems such as high processing difficulty and low dimensional accuracy. Furthermore, the resonant filter of this application embodiment can be a single-layer stacked, drawer-type design, resulting in a compact structure. This architecture facilitates subsequent multiplexer expansion. In addition, the resonant filter of this application embodiment is applicable to frequency bands above 5.5 GHz. Moreover, the input and output port settings of the resonant filter of this application embodiment are more flexible, adapting to different design requirements.

[0051] While the present invention has been described using the above embodiments, it should be noted that these descriptions are not intended to limit the invention. Rather, this invention encompasses modifications and similar arrangements that are obvious to those skilled in the art. Therefore, the scope of the patent application should be interpreted in the broadest possible sense to include all obvious modifications and similar arrangements.

[0052] 100: Resonant Filter 110: Outer shell 111: Receptacle 112: First inner surface 113: Second inner surface 114: First through hole 115: Second through hole 116: Reinforcing bars 117: Resonant Cavity 118: Base Plate 119: Shell 1191: First Opening 1192: Second opening 1193: Sidewall 120: Metal resonator 120a: First tap piece 120b: Second tap tip 121: Upright Section 122: First resonator 123: Extension 124: Second resonator 125: Coupled segment 126: Third resonator 127: Cover plate 128: Fourth resonator 129: Resonator 130: Input Port 132: First support seat 134: First Port Conductor 136: First Plinth 140: Output Port 142: Second support seat 144: Second Port Conductor 146: Second Plinth 150: First connecting bar 160: Second connecting bar 170: Intermediate resonator F: First direction C: Arrangement direction

Claims

1. A resonant filter, comprising: A housing having a receiving cavity and a first inner surface and a second inner surface disposed opposite to each other, and having a first through hole and a second through hole communicating with the receiving cavity; a plurality of metal resonators located in the receiving cavity and disposed on the first inner surface and the second inner surface, the metal resonators being substantially located on the same plane and distributed opposite to each other, the metal resonators being coupled to form a signal connection; an input port connected to the first through hole and connected to one of the metal resonators; and an output port connected to the second through hole and connected to another of the metal resonators; wherein the metal resonators include a first resonator, a second resonator, a third resonator and a fourth resonator connected in sequence, the first resonator and the fourth resonator being spaced apart on the second inner surface, the second resonator and the third resonator being spaced apart on the first inner surface, and the first resonator and the fourth resonator being disposed in different resonant cavities.

2. The resonant filter as described in claim 1, wherein, The housing is also provided with multiple partitions, which divide the accommodating cavity into multiple resonant cavities arranged in two rows. The metal resonant plates are disposed in the resonant cavities, and two adjacent resonant cavities are connected.

3. The resonant filter as described in claim 2, wherein, The second resonator and the third resonator are located in the same resonant cavity.

4. The resonant filter as described in claim 3, wherein, The input port and the output port are respectively connected to the first resonator and the fourth resonator.

5. The resonant filter as described in claim 3, wherein, Different resonant cavities are connected, and capacitive cross-coupling occurs between the first resonant plate and the fourth resonant plate.

6. The resonant filter as described in claim 5, wherein, It also includes a first connecting rib, which is substantially located on the same plane as the first resonant plate, and the first connecting rib connects the first resonant plate and the fourth resonant plate.

7. The resonant filter as described in claim 3, wherein, It also includes a second connecting rib, which is substantially located on the same plane as the second resonant plate, and the second connecting rib connects the second resonant plate and the third resonant plate.

8. The resonant filter as described in claim 7, wherein, The smaller the distance between the end of the second resonator away from the first inner surface and the end of the third resonator away from the first inner surface, the smaller the distance between the second connecting rib and the first inner surface; the larger the distance between the end of the second resonator away from the first inner surface and the end of the third resonator away from the first inner surface, the larger the distance between the second connecting rib and the first inner surface.

9. The resonant filter as described in claim 3, wherein, The first resonant plate, the second resonant plate, the third resonant plate, and the fourth resonant plate constitute a set of resonant plates. The metal resonant plates include N sets of resonant plates and N-1 intermediate resonant plates. An intermediate resonant plate is disposed between two adjacent sets of resonant plates. N is an integer greater than or equal to 2. Each of the N-1 intermediate resonant plates is disposed on the first inner surface or the second inner surface and is coupled with the fourth resonant plate and the first resonant plate on both sides to form a signal connection.

10. The resonant filter as claimed in claim 9, wherein, The input port and the output port are respectively connected to the first resonator of a first group of resonators and the fourth resonator of an Nth group of resonators.

11. The resonant filter as claimed in claim 9, wherein, The intermediate resonator plate disposed on the second inner surface, along with the fourth resonator plate and the first resonator plate adjacent to it on both sides, are disposed in the same resonant cavity.

12. The resonant filter as claimed in claim 9, wherein, The intermediate resonator plate disposed on the first inner surface is disposed in a different resonant cavity from the adjacent second and third resonator plates.

13. The resonant filter as claimed in claim 1, wherein, The housing includes a base plate, a shell, and a cover plate. The shell has a first opening and a second opening disposed opposite to each other. The base plate is disposed at the first opening, and the cover plate is disposed at the second opening. The base plate, the shell, and the cover plate surround to form the receiving cavity. The base plate has the first inner surface, and the cover plate has the second inner surface.

14. The resonant filter as claimed in claim 1, wherein, The first through hole and the second through hole are provided on the base plate or the cover plate.

15. The resonant filter as claimed in claim 14, wherein, The input port includes a first support base, and the metal resonator connected to the input port extends out of the housing through the first support base via a first tap. The first tap and the metal resonator connected to the input port are integrally formed. The output port includes a second support base, and the other metal resonator connected to the output port extends out of the housing through the second support base via a second tap. The second tap and the other metal resonator connected to the output port are integrally formed.

16. The resonant filter as claimed in claim 1, wherein, The first through hole and the second through hole are provided on the same side wall or different side walls of the housing.

17. The resonant filter as claimed in claim 16, wherein, The input port includes a first port conductor and a first base. One end of the first port conductor is connected to the metal resonator. The first base is engaged with the first through hole. The other end of the first port conductor passes through the first base and extends out of the housing. The output port includes a second port conductor and a second base. One end of the second port conductor is connected to the other metal resonator. The second base is engaged with the second through hole. The other end of the second port conductor passes through the second base and extends out of the housing.

18. The resonant filter as claimed in claim 1, wherein, Each of the metal resonators includes an upright segment, an extension segment extending from one end of the upright segment, and a coupling segment extending from one end of the extension segment away from the upright segment. The end of the upright segment away from the extension segment is fixed to the first inner surface or the second inner surface. The coupling segment of each of the metal resonators is close to the coupling segment of an adjacent metal resonator.

19. The resonant filter as claimed in claim 1, wherein, Each of these metal resonators is a sheet material having a metal surface or a metal sheet.

20. The resonant filter as claimed in claim 1, wherein, These metal resonators are not physically connected to each other.

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