Cavity resonator and cavity filter

Abstract

The application discloses a cavity resonator and a cavity filter. The cavity resonator comprises a resonant cavity and a resonant tube which is connected to the resonant cavity in a rotating manner. One end of the resonant tube is arranged outside the resonant cavity, and the other end is arranged inside the resonant cavity. One side of the resonant cavity which is opposite to the resonant tube is a stepped surface, and the stepped surface comprises at least two planes with different heights. The overlapping area of the resonant tube and the planes with different heights in the stepped surface changes with the rotation of the resonant tube. Through the above design, the process of adjusting the frequency of the filter is simplified, the production efficiency is improved, and the production cost is reduced.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a cavity resonator and a cavity filter. Background Technology

[0002] In base station communication products, filters play a crucial role as radio frequency modules in the entire system. Their primary function is to select communication signals and filter out noise or interference signals outside the communication frequency range. With the development of filters, low cost and lightweight design have become increasingly important. Currently, cavity resonators in cavity filters typically include a cavity, a resonant rod, a tuning screw, and a cover plate. The tuning screw is mounted on the cover plate via a threaded structure. By rotating the tuning screw, the capacitance between the resonant rod and the cover plate is changed, thereby altering the frequency characteristics of the cavity filter.

[0003] However, currently, the tuning screws of such cavity resonators need to be prepared in many different lengths during the production and debugging process, and then replaced according to the needs of the cavity resonator. This consumes a lot of time during the debugging process, thereby reducing production efficiency and increasing production costs. Summary of the Invention

[0004] The purpose of this application is to provide a cavity resonator and a cavity filter to simplify the process of adjusting the filter frequency, thereby improving production efficiency and reducing production costs.

[0005] This application discloses a cavity resonator, including a resonant cavity and a resonant tube rotatably connected to the resonant cavity. One end of the resonant tube is disposed outside the resonant cavity, and the other end is disposed inside the resonant cavity. The side of the resonant cavity opposite to the resonant tube is a stepped surface, and the stepped surface includes at least two planes with different heights. The overlap area between the resonant tube and the planes with different heights in the stepped surface changes with the rotation of the resonant tube.

[0006] Optionally, the resonant tube includes a resonant column and a resonant disk. The resonant disk is positioned directly opposite the stepped surface of the resonant cavity, and the side facing the stepped surface is a plane. One end of the resonant column passes through a through-hole in the resonant cavity and extends outside the resonant cavity. The other end is connected to the resonant disk located inside the resonant cavity. The cross-sectional area of ​​the resonant disk is larger than the cross-sectional area of ​​the resonant column, and the overlap area between the resonant disk and planes at different heights in the stepped surface changes with the rotation of the resonant column.

[0007] Optionally, the resonant column and the resonant cavity are coaxially arranged, and the central axis of the resonant cavity is located at the intersection of planes of different heights in the stepped surface; the orthographic projection of the resonant column is located within the orthographic projection of the resonant tube disk and is tangent to the edge of the orthographic projection of the resonant tube disk.

[0008] Optionally, the resonant tube disk has a fan-shaped structure, which includes two side edges, a apex edge, and an outer arc edge. One end of each of the two side edges is connected to both ends of the apex edge, and the other end of each of the two side edges is connected to both ends of the outer arc edge. The included angle formed by the two side edges is less than 180° and greater than 150°. Furthermore, the orthographic projection of the resonant tube is tangent to the orthographic projection of the apex edge.

[0009] Optionally, both sides are arc-shaped, and the centers of the two sides are set opposite to each other; the top corner side and the outer arc side are arc-shaped, and the centers of the top corner side and the outer arc side are set opposite to each other; the centers of the top corner side and the outer arc side coincide with the center of the resonant tube.

[0010] Optionally, the edge of the resonant tube disk is rounded in the direction perpendicular to the stepped surface; the resonant tube disk has a groove on the side facing away from the stepped surface, and the sidewall of the groove has the same thickness as the bottom.

[0011] Optionally, different planes in the stepped surface are connected by a transition surface, which is inclined to the stepped surface.

[0012] Optionally, the resonant cavity includes a cavity body and a cover plate. The cover plate covers the opening of the cavity body and has a through hole. The stepped surface is located at the bottom of the cavity body. The resonant column includes a first resonant column and a second resonant column. One end of the first resonant column passes through the through hole in the cover plate, extends to the outside of the cover plate, and is locked by a locking member in the cavity resonator. The locking member is disposed outside the resonant cavity to limit the length of the resonant tube outside the resonant cavity. The other end of the first resonant column is connected to the second resonant column located inside the cavity body. One end of the second resonant column is connected to the first resonant column, and the other end is connected to the resonant tube disk. The cross-sectional area of ​​the second resonant column is larger than the cross-sectional area of ​​the first resonant column and the cross-sectional area of ​​the through hole. The resonant tube disk is located inside the cavity body and is disposed opposite to the stepped surface at the bottom of the cavity body.

[0013] Optionally, the resonant cavity includes a cavity body and a cover plate, the cover plate covering the opening of the cavity body, the bottom of the cavity body having a through hole, and the stepped surface located on the side of the cover plate facing the cavity body; the resonant column includes a first resonant column and a second resonant column, one end of the first resonant column passing through the through hole at the bottom of the cavity body, extending to the outside of the cavity body, and being locked by a locking member in the cavity resonator; the locking member is disposed outside the resonant cavity to limit the length of the resonant tube outside the resonant cavity; the other end of the first resonant column is connected to the second resonant column located inside the cavity body; one end of the second resonant column is connected to the first resonant column, and the other end is connected to the resonant tube disk; the cross-sectional area of ​​the second resonant column is larger than the cross-sectional area of ​​the first resonant column and the cross-sectional area of ​​the through hole; the resonant tube disk is located inside the cavity body and is disposed opposite to the stepped surface in the cover plate.

[0014] This application also discloses a cavity filter, including the cavity resonator described above.

[0015] Compared to the current method of using a cavity resonator consisting of a cover plate, resonant rod, cavity, and tuning screw, and adjusting the resonant frequency by changing the length of the tuning screw, this application provides a cavity resonator composed of a resonant cavity and a resonant tube. The surface of the resonant cavity opposite the resonant tube is designed as a stepped surface of different heights. By rotating the resonant tube, it is aligned with the different heights of the stepped surface, thereby changing the distance between the resonant tube and the resonant cavity, and consequently, the capacitance between them. As shown in the resonant frequency calculation formula, a larger capacitance results in a lower frequency, and a smaller capacitance results in a higher frequency. Therefore, by rotating the resonant tube relative to the different heights of the stepped surface, the resonant frequency of the cavity resonator can be changed, achieving the effect of adjusting the frequency properties of the cavity filter. Furthermore, this frequency adjustment process does not require replacing any components within the cavity resonator, simplifying the process, improving production efficiency, and reducing production costs. Attached Figure Description

[0016] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings:

[0017] Figure 1 This is a cross-sectional schematic diagram of a cavity resonator provided in the first embodiment of this application;

[0018] Figure 2This is a cross-sectional schematic diagram of another cavity resonator provided in the first embodiment of this application;

[0019] Figure 3A This is a three-dimensional schematic diagram of the resonant tube in the cavity resonator provided in the first embodiment of this application;

[0020] Figure 3B This is a front view of the resonant tube in the cavity resonator provided in the first embodiment of this application;

[0021] Figure 3C This is a top view of the resonant tube in the cavity resonator provided in the first embodiment of this application;

[0022] Figure 4 This is a cross-sectional schematic diagram of a cavity resonator provided in the second embodiment of this application;

[0023] Figure 5 This is a cross-sectional schematic diagram of another cavity resonator provided in the second embodiment of this application.

[0024] Figure 6A This is a front view of the cavity structure in the cavity resonator provided in the third embodiment of this application;

[0025] Figure 6B This is a top view of the cavity structure in the cavity resonator provided in the third embodiment of this application;

[0026] Figure 7 This is a schematic block diagram of a cavity filter provided in this application.

[0027] Among them, 10 is a cavity filter; 100 is a cavity resonator; 110 is a resonant cavity; 111 is a stepped surface; 112 is a cavity; 113 is a cover plate; 114 is a through hole; 115 is a transition surface; 120 is a resonant tube; 121 is a resonant pillar; 1211 is the first resonant pillar; 1212 is the second resonant pillar; 122 is a resonant tube disk; a is a side edge; b is a apex edge; c is an outer arc edge; 124 is a groove; and 130 is a locking element. Detailed Implementation

[0028] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0029] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean non-exclusive inclusion, where one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0030] In addition, terms such as “center,” “horizontal,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” that indicate orientation or positional relationship are based on the orientation or relative positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0031] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0033] Example 1:

[0034] Figure 1 This is a cross-sectional schematic diagram of a cavity resonator provided in the first embodiment of this application, as shown below. Figure 1 As shown, the cavity resonator 100 includes a resonant cavity 110 and a resonant tube 120 rotatably connected to the resonant cavity 110. One end of the resonant tube 120 is disposed outside the resonant cavity 110, and the other end is disposed inside the resonant cavity 110. The side of the resonant cavity 110 opposite to the resonant tube 120 is a stepped surface 111, and the stepped surface 111 includes at least two planes with different heights. Figure 2 A cross-sectional schematic diagram of another cavity resonator 100 provided in the first embodiment of this application, combined with... Figure 1 and Figure 2As shown, the overlapping area of ​​the resonant tube 120 and the planes at different heights in the stepped surface 111 changes with the rotation of the resonant tube 120.

[0035] Compared to the current cavity resonator composed of a cover plate, resonant rod, cavity, and tuning screw, and whose frequency attributes are adjusted by changing the length of the tuning screw, this application provides a cavity resonator 100 composed of a resonant cavity 110 and a resonant tube 120. Tuning is achieved by rotating the resonant tube 120, eliminating the need for a conventional filter's tuning screw. The surface of the resonant cavity 110 opposite the resonant tube 120 is designed as a stepped surface 111 of different heights. By rotating the resonant tube 120 to face different planes, the distance between the resonant tube 120 and the resonant cavity 110 is adjusted, thereby changing the capacitance between them. As shown in the resonant frequency calculation formula, a larger capacitance results in a lower frequency, and a smaller capacitance results in a higher frequency. Therefore, by rotating the resonant tube 120 to face different planes within the resonant cavity 110, the resonant frequency of the cavity resonator 100 can be changed, achieving the effect of adjusting the frequency attributes of the cavity filter 10. Furthermore, during frequency adjustment, there is no need to replace the components in the cavity resonator 100, making the adjustment process simple, improving production efficiency, and reducing production costs.

[0036] Furthermore, the cavity resonator 100 described in this application avoids the impact of burrs in the threads and other factors affecting intermodulation and power in conventional filters, thus improving intermodulation and high-power performance, thereby increasing product yield, reducing production costs, and enhancing product competitiveness. Moreover, the resonant tube 120 does not need to move into the resonant cavity 110 during rotation, eliminating the safety distance for the tuning screw movement within the resonant cavity 110, further reducing the filter's size.

[0037] Furthermore, compared to the double-step surface scheme where both the resonant tube and the resonant cavity face each other as stepped surfaces, and the resonant tube is rotated to make the stepped surfaces of the resonant tube and the resonant cavity alternately concave and convex, this application only provides a stepped surface 111 on the surface of the resonant cavity 110 facing the resonant tube 120. The overlapping area of ​​the planes of different heights in the stepped surface 111 with the side of the resonant tube 120 facing the resonant cavity 110 changes with the rotation of the resonant tube 120. This design allows the resonant tube 120 to face either the plane furthest away in the stepped surface 111 of the resonant cavity 110 or the plane closest in the stepped surface 111 of the resonant cavity 110. This makes the adjustable distance between the resonant tube 120 and the stepped surface 111 the distance between the highest and lowest planes in the stepped surface 111. In the double-step surface scheme, as the resonant tube rotates, the distance between one step surface of the resonant tube and one step surface of the resonant cavity gradually increases, while the distance between the other step surface of the resonant tube and the other step surface of the resonant cavity gradually decreases. This results in both the increase and decrease of distance between the step surfaces of the resonant tube and the resonant cavity occurring simultaneously, thus maintaining the overall distance between the resonant tube and the resonant cavity within a stable range. Since the adjustable distance between the resonant tube 120 and the step surface 111 in this design is the distance between the highest and lowest planes of the step surface 111, there is no situation where the distances of the two opposing step surfaces 111 cancel each other out during rotation. Therefore, compared to the double-step surface scheme, the cavity resonator 100 in this design has a wider adjustable range of capacitance and resonant frequency, better meeting the application requirements.

[0038] Of course, the technical solution in this application can also be achieved by having one part of the resonant tube face the farthest plane in the step surface 111 of the resonant cavity 110, and another part face the closest plane in the step surface 111 of the resonant cavity 110. By rotating the resonant tube 120, the overlap area between the resonant tube 120 and the planes at different heights in the step surface 111 can be controlled, so as to achieve the effect of gradually changing the overall distance between the resonant tube 120 and the resonant cavity 110, and gradually changing the capacitance and resonant frequency of the cavity resonator 100, making it easier to precisely adjust the resonant frequency of the cavity resonator 100.

[0039] Specifically, the resonant tube 120 includes a resonant column 121 and a resonant tube disk 122. The resonant tube disk 122 is positioned directly opposite the stepped surface 111 of the resonant cavity 110, and the side opposite to the stepped surface 111 is a plane. One end of the resonant column 121 passes through the through hole 114 of the resonant cavity 110 and extends outside the resonant cavity 110. The other end is connected to the resonant tube disk 122 located inside the resonant cavity 110. The cross-sectional area of ​​the resonant tube disk 122 is larger than that of the resonant column 121, and the overlap area between the resonant tube disk 122 and the planes at different heights in the stepped surface 111 changes with the rotation of the resonant column 121.

[0040] Rotating the resonant column located outside the resonant cavity 110 can control the rotation of the resonant tube disk 122, thereby controlling the overlap area between the resonant tube disk 122 and the planes at different heights in the stepped surface 111, achieving the effect of adjusting the distance between the resonant tube 120 and the resonant cavity 110, and controlling the capacitance and resonant frequency of the cavity resonator 100. Figure 1 When the resonant tube disk 122 rotates to the position directly facing the protrusion (higher horizontal plane) in the step surface 111, the distance between the resonant tube disk 122 and the resonant tube 120 is the smallest, the parallel plate capacitance is the largest, and the resonant frequency is the lowest. Figure 2 When the resonant tube disk 122 rotates to the recessed position (lower horizontal plane) directly opposite the step surface 111, the distance between the resonant tube disk 122 and the resonant tube 120 is the largest, the parallel plate capacitance is the smallest, and the resonant frequency is the highest.

[0041] Since the resonant tube 120 has an additional resonant tube disk 122 opposite to the stepped surface 111 on the basis of the resonant column, the cross-sectional area of ​​the resonant tube disk 122 is larger than the cross-sectional area of ​​the resonant column 121, so that there is a large relative area between the resonant tube 120 and the stepped surface 111. As can be seen from the capacitance formula, the larger the area, the larger the capacitance. Therefore, the cavity resonator 100 has a large capacitance and a large resonant frequency, thereby improving the performance of the cavity filter 10.

[0042] In this embodiment, the cavity resonator 100 has a regular structure, wherein the resonant cavity 110 has a regular circular or square structure. The stepped surface 111 of the resonant cavity 110 can be composed of only two planes with different heights, each plane having the same area, and each plane being a semicircle or rectangle. Alternatively, the stepped surface 111 of the resonant cavity 110 can be composed of three or more planes with different heights, each plane having the same area, and each plane being a sector or triangle.

[0043] The resonant tube 120 can be an L-shaped structure, and the resonant column 121 is cylindrical and perpendicular to the resonant tube disk 122. The central axis of the resonant column 121 is coaxial with the resonant cavity 110. The central axis of the resonant cavity 110 is located at the intersection of planes of different heights in the stepped surface 111. In this way, no matter how the resonant column 121 rotates, the overlapping area with each plane of height in the stepped surface 111 is equal, so it will not affect the resonant frequency of the cavity resonator 100. The orthographic projection of the resonant column 121 is also located within the orthographic projection of the resonant tube disk 122 and is tangent to the edge of the orthographic projection of the resonant tube disk 122. The cross-sectional area of ​​the resonant tube disk 122 is also smaller than the area of ​​any plane in the step surface 111. In this way, the resonant tube disk 122 can be located only within one height plane range of the step surface 111, and when the resonant column 121 is slightly rotated, the resonant tube disk 122 will not rotate to other height plane ranges, thus avoiding the change of the tuned resonant frequency when the cavity resonator 100 is shaken, thereby improving the stability of the cavity resonator 100.

[0044] Of course, in this embodiment, the resonant column 121 can also be oblique or arc-shaped. The resonant tube disk 122 can achieve the purpose of overlapping with multiple planes of different heights by increasing the area or the length of both ends. As long as the overlapping area of ​​the planes of different heights in the step surface 111 and the side of the resonant tube disk 122 facing the resonant cavity 110 changes when the resonant column 121 is rotated.

[0045] like Figure 3A , 3B As shown in 3C, the stepped surface 111 is composed of two planes with different heights and equal areas. The resonant tube disk 122 has a fan-shaped structure, which includes two side edges a, a apex edge b, and an outer arc edge c. One end of each side edge a is connected to both ends of the apex edge b, and the other end of each side edge a is connected to both ends of the outer arc edge c. The included angle formed by the two side edges a is less than 180° and greater than 150°. Furthermore, the orthographic projection of the resonant column 121 is tangent to the orthographic projection of the apex edge.

[0046] In this embodiment, under the premise that the cross-sectional area of ​​the resonant tube disk 122 is smaller than the area of ​​a plane in the stepped surface 111, the cross-sectional area of ​​the resonant tube disk 122 is kept within a large range, thereby improving the resonant frequency attribute of the cavity resonator 100.

[0047] Furthermore, both sides a are arc-shaped, and their centers face away from each other; the apex b and outer arc c are also arc-shaped, and their centers face each other; the centers of the apex b and outer arc c coincide with the center of the resonant column 121. By making the edges of the resonant tube disk 122 arc-shaped, a smooth transition between the resonant tube disk 122 and the stepped surface 111 is ensured while the resonant column 121 rotates, preventing abrupt changes in height and thus avoiding abrupt changes in the electric field, achieving precise frequency control. Compared to a typical fan-shaped structure, the two sides a in this embodiment are concave arc-shaped. This not only achieves a smooth transition at the edges of the resonant tube disk 122 but also avoids situations where the side a overlaps with other height planes when the resonant tube disk 122 only needs to rotate to one height plane, thus better meeting usage requirements.

[0048] Furthermore, the edges of the resonant tube disk 122 are rounded in the direction perpendicular to the step surface 111; thus, the edges of the resonant tube disk 122 are arc-shaped in both the vertical and horizontal directions, which further ensures that the electric field will not change abruptly while the resonant tube 120 rotates; and also avoids the risk of tip discharge or arc discharge.

[0049] The resonant tube disk 122 has a groove 124 on the side facing away from the stepped surface 111. The groove 124 can be formed by bending the edge of the resonant tube disk 122. Specifically, the thickness of the resonant tube disk 122 is uniform throughout. The edge of the resonant tube disk 122 is bent in the direction away from the stepped surface 111, so that the edge of the resonant tube disk 122 is rounded in the direction perpendicular to the stepped surface 111, and the bent resonant tube disk 122 forms a groove 124 with a high edge and a low center. Of course, the groove 124 can also be directly carved in the middle of the resonant tube disk 122. Through the above design of the groove 124, the sidewall and bottom of the groove 124 have the same thickness, maintaining the uniformity of the resonant tube disk 122 and improving the stability of the resonant frequency attribute in the cavity resonator 100. In addition, it can also reduce the weight of the resonant tube disk 122 itself, reduce the tension on the resonant cavity 110, and prevent the resonant tube 120 from deforming.

[0050] In this embodiment, the resonant cavity 110 includes a cavity 112 and a cover plate 113. The cover plate 113 covers the opening of the cavity 112 and has a through hole 114. The stepped surface 111 is located at the bottom of the cavity 112. The resonant pillar 121 includes a first resonant pillar 1211 and a second resonant pillar 1212. One end of the first resonant pillar 1211 passes through the through hole 114 in the cover plate 113, extends to the outside of the cover plate 113, and is locked by a locking member 130 in the cavity resonator 100. The locking member 130 is disposed in the resonant cavity 110. Outside the cavity 110, the length of the resonant tube 120 is defined; the other end of the first resonant column 1211 is connected to the second resonant column 1212 located inside the cavity 112; one end of the second resonant column 1212 is connected to the first resonant column 1211, and the other end is connected to the resonant tube disk 122; the cross-sectional area of ​​the second resonant column 1212 is larger than the cross-sectional area of ​​the first resonant column 1211 and the cross-sectional area of ​​the through hole 114; the resonant tube disk 122 is located inside the cavity 112 and is disposed opposite to the stepped surface 111 at the bottom of the cavity 112.

[0051] Specifically, after adjusting the height of the resonant column 121 protruding from the cover plate 113, the first resonant column 1211 is fixed in place with the locking member 130, and the second resonant column 1212 abuts against the cover plate 113. This prevents the resonant tube 120 from moving up and down, avoiding other factors affecting the distance between the resonant tube 120 and the step surface, which could make it difficult to accurately adjust the resonant frequency of the cavity resonator 100. The locking member 130 can be a rigid nut. After the resonant tube 120 is rotated to the appropriate position, the rigid nut secures the resonant tube 120, ensuring good contact and reliability of all components in the cavity resonator 100. Furthermore, the first resonant column 1211 is elastic to the cover plate 113, ensuring good contact between the resonant tube 120 and the resonant cavity 110 while the tube rotates. This can be achieved by adding a spring between the first resonant column 1211 and the locking member 130, or by making the locking member 130 an elastic structure.

[0052] Furthermore, an inner hole is provided inside the resonant post 121, making the inside of the resonant post 121 hollow, thereby reducing the weight of the resonant post 121. The resonant post 121 can also be made of a mixture of two or more materials to achieve a temperature compensation effect, so that the resonant post 121 will not deform in environments with large temperature differences, and the resonant frequency attribute of the cavity resonator 100 will not change due to temperature factors.

[0053] In the cavity resonator 100, there are multiple resonant cavities 110 and multiple resonant tubes 120. The resonant tubes 120 are normally coupled to each other. Of course, the resonant tubes 120 can be normally coupled to each other through a fly rod. The resonant tubes 120 and the taps of the cavity resonator 100 are normally coupled to each other.

[0054] Example 2:

[0055] Figure 4 This is a cross-sectional schematic diagram of a cavity resonator provided in the second embodiment of this application. Unlike the first embodiment, the resonant cavity 110 also includes a cavity 112 and a cover plate 113. The cover plate 113 covers the opening of the cavity 112, but the bottom of the cavity 112 has a through hole 114. The stepped surface 111 is located in the cover plate 113 on the side facing the cavity 112. The resonant pillar 121 includes a first resonant pillar 1211 and a second resonant pillar 1212. One end of the first resonant pillar 1211 penetrates through the through hole 114 at the bottom of the cavity 112, extends to the outside of the cavity 112, and is secured by a locking member in the cavity resonator 100. 130 locking; the locking member 130 is disposed outside the resonant cavity 110 and is used to limit the length of the resonant tube 120 outside the resonant cavity 110; the other end of the first resonant column 1211 is connected to the second resonant column 1212 located inside the cavity 112; one end of the second resonant column 1212 is connected to the first resonant column 1211, and the other end is connected to the resonant tube disk 122; the cross-sectional area of ​​the second resonant column 1212 is larger than the cross-sectional area of ​​the first resonant column 1211 and the cross-sectional area of ​​the through hole 114; the resonant tube disk 122 is located inside the cavity 112 and is disposed opposite to the stepped surface 111 in the cover plate 113.

[0056] Combination Figure 5 As shown, when the first resonant column 1211 located outside the cavity 112 is rotated, the overlap between the resonant tube disk 122 and the plane at different heights in the stepped surface 111 can also be adjusted. Compared to the first embodiment where the first resonant column 1211 passes through the cover plate 113 for convenient installation, in this embodiment, the through hole 114 is provided in the cavity 112, and the first resonant column 1211 passes through the bottom of the cavity 112. Since the bottom of the cavity 112 is part of the cavity 112, it has good stability. Therefore, the bottom of the cavity 112 and the part of the cavity 112 near the through hole are not easily deformed by the resonant column 121, so the cavity resonator itself has good stability.

[0057] Example 3:

[0058] Figure 6AThis is a cross-sectional schematic diagram of the cavity in the cavity resonator provided in the third embodiment of this application. The third embodiment is a further improvement on the cavity 112 based on the first embodiment, combined with... Figure 6B As shown, different planes in the step surface 111 are connected by a transition surface 115. The cross section of the transition surface 115 can be a diagonal line or an arc, and the transition surface 115 is inclined to the step surface 111.

[0059] In this embodiment, when the resonant disk 122 rotates from one height plane to another, the presence of the transition surface 115 causes the resonant frequency in the cavity resonator 100 to change gradually, rather than abruptly. This improves the precision of resonant frequency adjustment and enhances the quality of the cavity resonator 100 and the cavity filter 10. Of course, this embodiment can also be an improvement based on the second embodiment, where a transition surface is provided between different height planes on the stepped surface of the cover plate.

[0060] like Figure 7 As shown, this application also discloses a cavity filter 10, including at least one cavity resonator 100 as described in the above embodiments.

[0061] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0062] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A cavity resonator, comprising a resonant cavity and a resonant tube rotatably connected relative to the resonant cavity, wherein one end of the resonant tube is disposed outside the resonant cavity and the other end is disposed inside the resonant cavity, characterized in that, The side of the resonant cavity opposite to the resonant tube is a stepped surface, and the stepped surface includes at least two planes with different heights. The overlap area between the resonant tube and the planes at different heights in the stepped surface changes with the rotation of the resonant tube. The resonant tube includes a resonant pillar and a resonant tube disk. The resonant tube disk is disposed opposite to the stepped surface of the resonant cavity, and the side opposite to the stepped surface is a plane. One end of the resonant column passes through the through hole of the resonant cavity and extends outside the resonant cavity; the other end is connected to the resonant tube disk located inside the resonant cavity. The cross-sectional area of ​​the resonant tube disk is larger than that of the resonant column, and the overlap area between the resonant tube disk and the planes at different heights in the stepped surface changes with the rotation of the resonant column. The resonant column and the resonant cavity are coaxially arranged, and the central axis of the resonant cavity is located at the intersection of planes of different heights in the stepped surface; The orthographic projection of the resonant column lies within the orthographic projection of the resonant tube disk and is tangent to the edge of the orthographic projection of the resonant tube disk; the cross-sectional area of ​​the resonant tube disk is also smaller than the area of ​​any plane in the stepped surface.

2. The cavity resonator as described in claim 1, characterized in that, The resonant tube disk has a fan-shaped structure, which includes two side edges, a top corner edge, and an outer arc edge. One end of each of the two side edges is connected to both ends of the top corner edge, and the other end of each of the two side edges is connected to both ends of the outer arc edge. The included angle formed by the two sides is less than 180° and greater than 150°; and the orthographic projection of the resonant column is tangent to the orthographic projection of the top corner side.

3. The cavity resonator as described in claim 2, characterized in that, Both sides are arc-shaped, and the centers of the two sides are set opposite to each other; Both the apex and the outer arc are rounded, and their centers are positioned opposite each other. The centers of the apex and outer arc sides coincide with the center of the resonant tube.

4. The cavity resonator as described in claim 3, characterized in that, The edges of the resonant tube disk are rounded in the direction perpendicular to the stepped surface; The resonant tube disk has a groove on the side facing away from the stepped surface, and the sidewall of the groove has the same thickness as the bottom.

5. The cavity resonator as described in claim 1, characterized in that, Different planes in the stepped surface are connected by transition surfaces, which are inclined to the stepped surface.

6. The cavity resonator according to any one of claims 1-5, characterized in that, The resonant cavity includes a cavity body and a cover plate. The cover plate covers the opening of the cavity body and has a through hole. The stepped surface is located at the bottom of the cavity body. The resonant column includes a first resonant column and a second resonant column. One end of the first resonant column passes through a through hole in the cover plate, extends to the outside of the cover plate, and is locked by a locking member in the cavity resonator. The locking member is disposed outside the resonant cavity and is used to limit the length of the resonant tube outside the resonant cavity. The other end of the first resonant post is connected to the second resonant post located inside the cavity; One end of the second resonant post is connected to the first resonant post, and the other end is connected to the resonant tube disk; the cross-sectional area of ​​the second resonant post is larger than the cross-sectional area of ​​the first resonant post and the cross-sectional area of ​​the through hole; The resonant tube disk is located inside the cavity and is positioned opposite to the stepped surface at the bottom of the cavity.

7. The cavity resonator according to any one of claims 1-5, characterized in that, The resonant cavity includes a cavity body and a cover plate. The cover plate covers the opening of the cavity body. The bottom of the cavity body is provided with a through hole. The stepped surface is located on the side of the cover plate facing the cavity body. The resonant column includes a first resonant column and a second resonant column. One end of the first resonant column passes through a through hole at the bottom of the cavity, extends to the outside of the cavity, and is locked by a locking member in the cavity resonator. The locking member is disposed outside the resonant cavity and is used to limit the length of the resonant tube outside the resonant cavity. The other end of the first resonant post is connected to the second resonant post located inside the cavity; One end of the second resonant post is connected to the first resonant post, and the other end is connected to the resonant tube disk; the cross-sectional area of ​​the second resonant post is larger than the cross-sectional area of ​​the first resonant post and the cross-sectional area of ​​the through hole; The resonant tube disk is located inside the cavity and is positioned opposite to the stepped surface in the cover plate.

8. A cavity filter, characterized in that, Includes the cavity resonator as described in any one of claims 1-7.

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