filter

Abstract

The application relates to the field of radio frequency devices, and provides a filter which comprises a cavity with resonance cavities, a cover plate covering the cavity, at least one resonance rod, at least one nut and at least one fastening screw, the cover plate is provided with at least one first through hole; each resonance rod is arranged in each resonance cavity, the resonance rod is provided with a resonance hole and a second through hole arranged at the bottom of the resonance hole; the nut is arranged on the side of the first through hole away from the cavity; the fastening screw is provided with a head and a nail part which are connected in sequence, the head of the fastening screw is stopped at the bottom of the resonance hole, the nail part of the fastening screw is arranged in the second through hole and the first through hole in sequence and is threadedly connected with the nut. Compared with the existing filter, the filter provided by the application can obviously simplify the tuning rod, and the adjustment of the resonance frequency of the resonance cavity is not affected, so that the structure and assembly of the filter can be effectively simplified, the assembly time of the filter can be effectively shortened, and the use performance of the filter can be effectively guaranteed and improved.

Description

Technical Field

[0001] This invention belongs to the field of radio frequency device technology, and particularly relates to a filter. Background Technology

[0002] like Figure 1 , Figure 2 As shown, existing filters typically include a cavity 10', a cover plate 20' that covers the cavity 10', at least one resonant rod 40' mounted on the inner wall of the cavity 10' opposite to the cover plate 20' by fastening screws 30', and at least one tuning rod 50' passing through the cover plate 20' and disposed opposite to the resonant rod 40'. The tuning rod 50' is used to adjust the resonant frequency of the resonant cavity 11' where the resonant rod 40' is located. Therefore, as the number of resonant rods 40' increases, the number of tuning rods 50' required for the filter also increases, resulting in a complex filter structure and long assembly time. Summary of the Invention

[0003] The purpose of this invention is to provide a filter to solve the technical problem that existing filters require numerous tuning rods, resulting in complex structures and long assembly times.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a filter, comprising a cavity having at least one resonant cavity and a cover plate covering the cavity, wherein the cover plate has at least one through-hole; the filter further comprises:

[0005] At least one resonant rod is disposed in each of the resonant cavities, and the resonant rod has a resonant hole and a second through hole disposed at the bottom of the resonant hole;

[0006] At least one nut is located on the side of the first perforation opposite to the cavity;

[0007] At least one fastening screw has a head and a nail portion connected in sequence. The head of the fastening screw stops at the bottom of the resonant hole, and the nail portion of the fastening screw passes through the second through hole and the first through hole in sequence, and is threadedly connected to the nut.

[0008] In one embodiment, the head of the fastening screw has at least one corner in its circumferential direction, and the bottom of the resonant hole is provided with a limiting groove for the fastening screw to be limited and accommodated therein.

[0009] The resonant rod includes a rod portion and a disk portion connected in sequence. The disk portion of the resonant rod is a polygonal disk, an irregularly shaped disk, or an eccentric disk whose center is offset from the central axis of the rod portion.

[0010] In one embodiment, the head of the fastening screw has at least one corner portion in the circumferential direction thereof, and the bottom of the resonant hole is provided with a limiting groove for limiting the accommodation of the fastening screw therein.

[0011] The resonant rod comprises a rod portion and a disc portion connected in sequence, and the cross-sectional shape of the rod portion of the resonant rod perpendicular to the axial direction thereof is polygonal or special-shaped.

[0012] In one embodiment, the head of the fastening screw has at least one corner portion in the circumferential direction thereof, and the bottom of the resonant hole is provided with a limiting groove for limiting the accommodation of the fastening screw therein.

[0013] The resonant rod is in the shape of a straight rod, and the cross-sectional shape of the resonant rod perpendicular to the axial direction thereof is polygonal or special-shaped.

[0014] In one embodiment, the first through hole is a light hole.

[0015] In one embodiment, the cover plate is provided with a first groove on the side thereof away from the cavity, the bottom of the first groove forms a deformed portion, and the first through hole is arranged on the deformed portion.

[0016] In one embodiment, the cover plate is provided with a second groove on the side thereof away from the cavity, and the groove bottom of the second groove is provided with the first groove.

[0017] The filter further comprises at least one elastic sheet, the circumferential edge of the elastic sheet elastically abuts against the groove wall of the second groove, the middle portion of the elastic sheet is provided with a third through hole for the nail portion of the fastening screw to pass through, and the middle portion of the elastic sheet elastically abuts against the nut.

[0018] In one embodiment, the deformed portion is provided with a boss, and the first through hole is arranged on the boss.

[0019] In one embodiment, the filter further comprises at least one elastic sheet arranged on the side of the cover plate facing the cavity, the circumferential edge of the elastic sheet elastically abuts against the cover plate, the middle portion of the elastic sheet is provided with a third through hole for the nail portion of the fastening screw to pass through, and the middle portion of the elastic sheet elastically abuts against the resonant rod.

[0020] In one embodiment, the side of the cover plate facing the cavity is provided with a third groove, and the circumferential edge of the elastic sheet elastically abuts against the groove wall of the third groove.

[0021] The present application provides the following beneficial effects:

[0022] The filter provided by the embodiment of the present application is characterized in that: in each resonant cavity, the resonant rod is installed on one side of the cover plate by sequentially penetrating the resonant rod and the cover plate through the fastening screw and then threadedly connecting the fastening screw with the nut, and the resonant rod and the inner wall of the cavity opposite to the cover plate are spaced apart and have a capacitive coupling value. Therefore, when the resonant frequency of the resonant cavity is adjusted, the nut can be conveniently rotated to cause the fastening screw threadedly connected with the nut to move upward or downward, thereby adjusting the distance between the resonant rod and the inner wall of the cavity opposite to the cover plate, adjusting the capacitive coupling value formed between the resonant rod and the inner wall of the cavity opposite to the cover plate, and adjusting the resonant frequency of the resonant cavity. The adjustment is very convenient, and the adjustment amount is accurately controllable. Therefore, compared with the existing filter, the filter provided by the embodiment of the present application can obviously simplify the tuning rod, and does not affect the adjustment of the resonant frequency of the resonant cavity, thereby effectively simplifying the structure and assembly of the filter, effectively shortening the assembly time of the filter, and effectively guaranteeing and improving the use performance of the filter. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 A perspective view of the filter provided by the prior art;

[0025] Figure 2 A perspective view of the filter provided by the prior art; Figure 1 A sectional view of the filter provided by the prior art;

[0026] Figure 3 A perspective view of the filter provided by the embodiment one of the present application;

[0027] Figure 4 A sectional view of the filter provided by the embodiment one of the present application; Figure 3 A sectional view of the filter provided by the embodiment one of the present application;

[0028] Figure 5 An exploded view of the filter provided by the embodiment one of the present application; Figure 3 An exploded view of the filter provided by the embodiment one of the present application;

[0029] Figure 6 An exploded view of the resonant rod and the fastening screw provided by the embodiment one of the present application; Figure 5 An exploded view of the resonant rod and the fastening screw provided by the embodiment one of the present application;

[0030] Figure 7 A perspective view of the filter provided by the embodiment four of the present application;

[0031] Figure 8 A perspective view of the filter provided by the embodiment four of the present application; Figure 7A cross-sectional view of the filter provided;

[0032] Figure 9 For Figure 7 An exploded schematic view of the filter provided.

[0033] In the drawings:

[0034] 10' - cavity, 11' - resonant cavity, 20' - cover plate, 30' - fastening screw, 40' - resonant rod, 50' - tuning rod, 60' - coupling rod;

[0035] 10 - cavity, 11 - resonant cavity; 20 - cover plate, 21 - first through hole, 22 - first slot, 23 - deformation, 231 - boss, 24 - second slot; 30 - resonant rod, 31 - resonant hole, 32 - second through hole, 33 - limiting slot, 34 - rod part, 35 - disc part; 40 - nut; 50 - fastening screw, 51 - head, 511 - corner, 52 - nail part; 60 - elastic sheet, 61 - third through hole. DETAILED DESCRIPTION

[0036] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0037] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0038] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0039] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and other terms should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] As shown in Figure 1 、 Figure 2 In the prior art, the filter generally includes a cavity 10', a cover plate 20' covering the cavity 10', at least one resonant rod 40' mounted on the inner wall opposite to the cover plate 20' of the cavity 10' through a fastening screw 30', and at least one tuning rod 50' penetrating the cover plate 20' and arranged opposite to the resonant rod 40', the tuning rod 50' being used to adjust the resonant frequency of the resonant cavity 11' in which the resonant rod 40' is located. Based on this, as the number of resonant rods 40' increases, the number of tuning rods 50' required to be provided on the filter will be more and more.

[0041] In addition, the resonant cavities 11' also need to be coupled according to a predetermined coupling relationship, and a coupling window is arranged between each two coupled resonant cavities 11'. For this purpose, the filter is usually also provided with a coupling rod 60' penetrating the cover plate 20' and opposite to the coupling window, and the coupling rod 60' is used to adjust the coupling strength between the corresponding two resonant cavities 11' corresponding to the coupling window. Based on this, as the number of resonant rods 40' and coupling windows increases, the number of coupling rods 60' required to be provided on the filter will also be more and more.

[0042] Therefore, the existing filter inevitably has problems such as too many parts, complex structure, complicated assembly, and long assembly time.

[0043] Therefore, the present application provides a filter which can effectively simplify the structure and assembly, and does not affect the filtering performance and tuning performance of the filter.

[0044] The specific implementation of the present application will be described in more detail in combination with specific embodiments as follows:

[0045] Embodiment one

[0046] Please refer to Figure 3 、 Figure 4 、 Figure 5The embodiment of the present application provides a filter, which comprises a cavity 10, a cover plate 20, at least one resonant rod 30, at least one nut 40 and at least one fastening screw 50. The cavity 10 has at least one resonant cavity 11; the cover plate 20 covers the cavity 10, and the cover plate 20 is provided with at least one first through hole 21; the number of the resonant cavity 11, the first through hole 21, the resonant rod 30, the nut 40 and the fastening screw 50 corresponds; each resonant rod 30 is arranged in each resonant cavity 11, and the resonant rod 30 has a resonant hole 31 and a second through hole 32 arranged at the bottom of the resonant hole 31; the nut 40 is located on the side of the first through hole 21 away from the cavity 10; the fastening screw 50 has a head 51 and a nail part 52 connected in sequence, the head 51 of the fastening screw 50 is stopped at the bottom of the resonant hole 31, and the nail part 52 of the fastening screw 50 is sequentially arranged in the second through hole 32 and the first through hole 21 and is threadedly connected with the nut 40.

[0047] It should be noted that the cavity 10 can be provided with one or more resonant cavities 11. When the resonant cavity 11 is provided with a plurality of resonant cavities 11, the plurality of resonant cavities 11 can be arranged and coupled according to the required coupling relationship, wherein a coupling window communicating with each other is arranged between the two resonant cavities 11.

[0048] It should also be noted that in each resonant cavity 11, the resonant rod 30 is installed on the cover plate 20 by the fastening screw 50 and the nut 40 in the posture that the orifice of the resonant hole 31 faces away from the cover plate 20. At this time, the resonant rod 30 is relatively stable by being supported by the head 51 of the fastening screw 50; the resonant rod 30 and the inner wall of the cavity 10 opposite to the cover plate 20 are arranged at intervals and generate a capacitance coupling value.

[0049] Based on this, when the frequency is adjusted, the position of the nut 40 is basically close to the cover plate 20, that is, the axial position of the nut 40 is basically unchanged (the axial direction refers to the direction along the central axis of the nut 40 / fastening screw 50), the nut 40 is rotated forward (which is a relative concept with the reverse rotation in the following), so that the fastening screw 50 threadedly connected with the nut 40 generates a downward displacement, thereby relatively narrowing the distance between the resonant rod 30 and the inner wall of the cavity 10 opposite to the cover plate 20; conversely, the nut 40 can be rotated in the reverse direction, so that the fastening screw 50 threadedly connected with the nut 40 generates an upward displacement, thereby relatively widening the distance between the resonant rod 30 and the inner wall of the cavity 10 opposite to the cover plate 20; and then the capacitance coupling value formed between the resonant rod 30 and the inner wall of the cavity 10 opposite to the cover plate 20 can be adjusted, the resonant frequency of the resonant cavity 11 can be adjusted, the adjustment is convenient, and the adjustment amount is controllable.

[0050] Therefore, compared with the prior filter, the filter provided by the embodiment can obviously simplify the tuning rod, so that the structure and assembly of the filter are simplified, the assembly time of the filter is shortened, and the use performance of the filter is obviously better.

[0051] Therefore, compared with the prior filter, the filter provided by the embodiment can obviously simplify the tuning rod, so that the structure and assembly of the filter are simplified, the assembly time of the filter is shortened, and the use performance of the filter is obviously better.

[0052] Please refer to Figure 3 、 Figure 4 、 Figure 6 In the embodiment, the head 51 of the fastening screw 50 has at least one corner portion 511 around the circumference, and the bottom of the resonant hole 31 is provided with a limiting groove 33 for limiting and accommodating the fastening screw 50; the resonant rod 30 comprises a rod portion 34 and a disc portion 35 connected in sequence, and the disc portion 35 of the resonant rod 30 is a polygonal disc, a special-shaped disc or an eccentric disc with the center being arranged in a position deviated from the central axis of the rod portion 34.

[0053] It should be noted that the head 51 of the fastening screw 50 can have one or more corner portions 511, for example, the fastening screw 50 can be a four-corner head screw, a five-corner head screw, a six-corner head screw, etc. The shape and size of the limiting groove 33 correspond to the shape and size of the head 51 of the fastening screw 50 respectively. In this way, under the premise that the head 51 of the fastening screw 50 is aligned and limited and accommodated in the limiting groove 33, the resonant rod 30 can be driven to rotate synchronously by rotating the fastening screw 50.

[0054] It should be further noted that, in the embodiment, the resonant rod 30 is a resonant rod 30 with a disc portion 35, and the resonant frequency of the resonant rod 30 with the disc portion 35 is relatively smaller than that of the resonant rod 30 without the disc portion 35.

[0055] Among them, the disk portion 35 of the resonant rod 30 can be a polygonal disk, specifically, the shape formed by the periphery of the disk portion 35 of the resonant rod 30 is polygonal, such as triangle, quadrilateral, pentagon, hexagon, etc.

[0056] Alternatively, the disk portion 35 of the resonant rod 30 can be an irregularly shaped disk, specifically, the shape formed by the periphery of the disk portion 35 of the resonant rod 30 is irregular, such as an irregular shape with straight line segments and arc segments, etc.

[0057] Alternatively, the disk portion 35 of the resonant rod 30 can be an eccentric disk whose center is offset from the central axis of the rod portion 34. Specifically, the distance from the circumference of the disk portion 35 of the resonant rod 30 to the central axis of the rod portion 34 is not equal.

[0058] Regardless of which of the above embodiments the disk portion 35 of the resonant rod 30 adopts, when the disk portion 35 of the resonant rod 30 rotates, the distance between the disk portion 35 of the resonant rod 30 and the coupling window provided on one side of the resonant rod 30 will change.

[0059] Therefore, by adopting the above scheme, when resonant cavity 11 is coupled to another resonant cavity 11 via a coupling window, the resonant rod 30 can be rotated synchronously by rotating the fastening screw 50, thereby changing the distance between the disk portion 35 of the resonant rod 30 and the coupling window, and thus changing the distance between the disk portions 35 of the two resonant rods 30 located on opposite sides of the coupling window. This allows for adjustment of the coupling strength between the two resonant cavities 11 corresponding to the coupling window, which is convenient and the adjustment amount is controllable. It is evident that, compared to existing filters, the filter provided in this embodiment can significantly simplify the coupling rod without affecting the adjustment of the coupling strength between the two resonant cavities 11 corresponding to the coupling window. This further simplifies the filter's structure and assembly, shortens the filter's assembly time, and further ensures and improves the filter's performance.

[0060] Please see Figure 3 , Figure 4 , Figure 5 In this embodiment, the first perforation 21 is a light hole.

[0061] By adopting the above solution, when the fastening screw 50 passing through the first through hole 21 rotates, the risk of mutual wear between the fastening screw 50 and the first through hole 21 can be effectively reduced, and the risk of burrs or debris being generated between the fastening screw 50 and the first through hole 21 and falling into the resonant cavity 11 can be effectively reduced, thereby further ensuring and improving the tuning effect and performance indicators of the filter.

[0062] Please see Figure 3 , Figure 4 , Figure 5In the embodiment, the cover plate 20 is provided with a first slot 22 on the side away from the cavity 10, the bottom of the first slot 22 forms a deformation part 23, and the first through hole 21 is arranged on the deformation part 23.

[0063] By adopting the above scheme, the deformation part 23 with a thickness obviously thinner than other regions of the cover plate 20 can be formed at the bottom of the first slot 22. Based on this, when the resonant rod 30 is displaced upward or downward along with the fastening screw 50, the resonant rod 30 and the fastening screw 50 can drive the deformation part 23 to adaptively produce plastic deformation, thereby effectively guaranteeing and improving the adjustability, adjustable range and tuning sensitivity of the resonant frequency of the resonant cavity 11.

[0064] During this period, the deformation part 23 also abuts against the resonant rod 30 to relatively stabilize the upright state of the resonant rod 30, thereby helping to stabilize the tuning effect and performance index of the filter.

[0065] Please refer to Figure 3 、 Figure 4 、 Figure 5 In the embodiment, the cover plate 20 is provided with a second slot 24 on the side away from the cavity 10, and the bottom of the second slot 24 is provided with the first slot 22; the filter further comprises at least one elastic sheet 60, the number of the elastic sheets 60 corresponds to the number of the resonant rods 30, the periphery of the elastic sheet 60 elastically abuts against the slot wall of the second slot 24, the middle part of the elastic sheet 60 is provided with a third through hole 61 for the nail part 52 of the fastening screw 50 to pass through, and the middle part of the elastic sheet 60 elastically abuts against the nut 40.

[0066] By adopting the above scheme, the planar movement of the elastic sheet 60 and the movement of the elastic sheet 60 in the direction close to the cover plate 20 can be limited through the second slot 24, so as to stabilize the position of the elastic sheet 60 and facilitate the elastic sheet 60 to reliably exert the elastic abutting effect; the nail part 52 of the fastening screw 50 passing through the third through hole 61 can produce balanced radial abutting effect in all directions, and the nut 40 located thereon can produce reliable axial abutting effect, so as to stabilize the state of the nut 40, the fastening screw 50 and the resonant rod 30 from multiple dimensions, thereby effectively reducing the risk of shaking, loosening and other phenomena of the nut 40, the fastening screw 50 and the resonant rod 30, and further stabilizing the tuning effect and performance index of the filter.

[0067] Please refer to Figure 3 、 Figure 4 、 Figure 5 In the embodiment, the deformation part 23 is provided with a boss 231, and the first through hole 21 is arranged on the boss 231.

[0068] It should be noted that the area near the connection between the deformation part 23 and the fastening screw 50, i.e., the boss 231 setting area, will have a larger deformation amount relative to other areas of the deformation part 23 under the action of the fastening screw 50 and the resonant rod 30.

[0069] Based on this, by adopting the above scheme, the thickness of the area near the connection between the thickened deformation part 23 and the fastening screw 50 can be increased based on the boss 231, so as to relatively strengthen the structural strength of the connection between the deformation part 23 and the fastening screw 50, thereby effectively reducing the risk of rupture of the boss 231 setting area, and further protecting and prolonging the service life of the filter.

[0070] Embodiment Two

[0071] The difference between this embodiment and Embodiment One is that:

[0072] Please refer to Figure 3 , Figure 4 , Figure 6 In this embodiment, the head 51 of the fastening screw 50 has at least one corner 511 in its circumferential direction, and the bottom of the resonant hole 31 is provided with a limiting groove 33 for limiting and accommodating the fastening screw 50; the resonant rod 30 includes a rod part 34 and a disc part 35 connected in sequence, and the rod part 34 of the resonant rod 30 has a polygonal or special-shaped cross-sectional shape perpendicular to its axial direction.

[0073] It should be noted that the head 51 of the fastening screw 50 can have one or more corners 511, for example, the fastening screw 50 can be a four-cornered head screw, a five-cornered head screw, a six-cornered head screw, etc. The shape and size of the limiting groove 33 correspond to the shape and size of the head 51 of the fastening screw 50, respectively. In this way, under the premise that the head 51 of the fastening screw 50 is aligned and limited and accommodated in the limiting groove 33, the resonant rod 30 can be driven to rotate synchronously by rotating the fastening screw 50.

[0074] It should also be noted that in this embodiment, the resonant rod 30 is a resonant rod 30 with a disc part 35, and the resonant frequency of the resonant rod 30 with a disc part 35 is relatively smaller than that of the resonant rod 30 without a disc part 35.

[0075] Among them, the rod part 34 of the resonant rod 30 has a polygonal or special-shaped cross-sectional shape perpendicular to its axial direction, so that when the rod part 34 of the resonant rod 30 rotates, the distance between the rod part 34 of the resonant rod 30 and the coupling window provided on one side of the resonant rod 30 will change.

[0076] Therefore, by adopting the above scheme, when the resonant cavity 11 and another resonant cavity 11 are coupled through the coupling window, the resonant rod 30 can be driven to rotate synchronously by rotating the fastening screw 50, so as to change the distance between the rod part 34 of the resonant rod 30 and the coupling window, and then change the distance between the rod parts 34 of the two resonant rods 30 located on the opposite sides of the coupling window, so as to adjust the coupling strength between the coupling window and the corresponding two resonant cavities 11. The adjustment is convenient, and the adjustment amount is controllable. As can be seen, compared with the existing filter, the filter provided in the embodiment can further simplify the coupling rod, and does not affect the adjustment of the coupling strength between the coupling window and the corresponding two resonant cavities 11, so that the structure and assembly of the filter can be further simplified, the assembly time of the filter can be further shortened, and the use performance of the filter can be further guaranteed and improved.

[0077] Of course, in other possible embodiments, the "disc part 35 of the resonant rod 30 is a polygonal disc, a special-shaped disc or an eccentric disc with the center being misaligned with the central axis of the rod part 34", and the "rod part 34 of the resonant rod 30 has a polygonal or special-shaped cross section perpendicular to the axial direction" can be combined, so that the coupling strength between the coupling window and the corresponding two resonant cavities 11 can also be adjusted by rotating the resonant rod 30.

[0078] Embodiment Three

[0079] The difference between the embodiment and the embodiment one is that:

[0080] Please refer to Figure 3 , Figure 4 , Figure 6 In the embodiment, the head 51 of the fastening screw 50 has at least one corner 511 in the circumferential direction, and the hole bottom of the resonant hole 31 is provided with a limiting groove 33 for limiting and accommodating the fastening screw 50. The resonant rod 30 is a straight rod, and the resonant rod 30 has a polygonal or special-shaped cross section perpendicular to the axial direction.

[0081] It should be noted that the head 51 of the fastening screw 50 can have one or more corners 511, for example, the fastening screw 50 can be a four-cornered head screw, a five-cornered head screw, a six-cornered head screw, etc. The shape and size of the limiting groove 33 correspond to the shape and size of the head 51 of the fastening screw 50. In this way, under the premise that the head 51 of the fastening screw 50 is aligned and limited and accommodated in the limiting groove 33, the resonant rod 30 can be driven to rotate synchronously by rotating the fastening screw 50.

[0082] It should be further noted that in the embodiment, the resonant rod 30 is a resonant rod 30 without a disc part 35, and the resonant frequency of the resonant rod 30 without the disc part 35 is relatively greater than that of the resonant rod 30 with the disc part 35.

[0083] The resonant rod 30 has a polygonal or special-shaped cross-sectional shape perpendicular to its axial direction. When the resonant rod 30 rotates, the distance between the resonant rod 30 and the coupling window arranged on one side of the resonant rod 30 changes.

[0084] Therefore, when the resonant cavity 11 and another resonant cavity 11 are coupled through the coupling window, the resonant rod 30 can be rotated synchronously by rotating the fastening screw 50, so as to change the distance between the resonant rod 30 and the coupling window, and then change the distance between the two resonant rods 30 on the opposite sides of the coupling window, so as to adjust the coupling strength between the two resonant cavities 11 corresponding to the coupling window. The adjustment is convenient, and the adjustment amount is controllable. It can be seen that, compared with the existing filter, the filter provided in the embodiment can further simplify the coupling rod, and does not affect the adjustment of the coupling strength between the two resonant cavities 11 corresponding to the coupling window, so as to further simplify the structure and assembly of the filter, further shorten the assembly time of the filter, and further guarantee and improve the use performance of the filter.

[0085] Embodiment Four

[0086] The difference between the embodiment and the embodiment one is that:

[0087] Please refer to Figure 7 , Figure 8 , Figure 9 In the embodiment, the filter further comprises at least one elastic sheet 60 arranged on the side of the cover plate 20 facing the cavity 10. The number of the elastic sheets 60 corresponds to the number of the resonant rods 30. The periphery of the elastic sheet 60 elastically abuts against the cover plate 20. The middle part of the elastic sheet 60 is provided with a third through hole 61 for the nail part 52 of the fastening screw 50 to pass through. The middle part of the elastic sheet 60 elastically abuts against the resonant rod 30.

[0088] By adopting the above scheme, the elastic sheet 60 can be elastically arranged between the cover plate 20 and the resonant rod 30, and the elastic sheet 60 can produce balanced radial abutment effect on the nail part 52 of the fastening screw 50 passing through the third through hole 61. Based on this, the state of the fastening screw 50 and the resonant rod 30 can be reliably and stably fixed from multiple dimensions, so as to effectively reduce the risk of shaking and loosening of the fastening screw 50 and the resonant rod 30, and further stabilize the tuning effect and performance index of the filter.

[0089] Please refer to Figure 7 , Figure 8 , Figure 9 In the embodiment, the side of the cover plate 20 facing the cavity 10 is provided with a third groove (not shown in the figure, which can be referred to the arrangement of the second groove 24 in the embodiment one). The periphery of the elastic sheet 60 elastically abuts against the groove wall of the third groove.

[0090] By adopting the above scheme, the planar movement and movement in the direction close to the cover plate 20 of the elastic sheet 60 can be limited by the third groove, so as to stabilize the position of the elastic sheet 60, thereby facilitating the elastic sheet 60 to reliably exert the elastic resisting effect.

[0091] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement or improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A filter comprising a cavity having a plurality of resonant cavities and a cover plate covering the cavities, characterized by, The cover plate is provided with a plurality of first through holes; the filter further comprises: a plurality of resonant rods arranged in the resonant cavities, the resonant rods having resonant holes and second through holes arranged at the bottoms of the resonant holes; the resonant rods comprise rod portions and disc portions connected in sequence, and the disc portions of the resonant rods are polygonal discs, special-shaped discs or eccentric discs with the centers thereof arranged in positions deviated from the central axes of the rod portions; a plurality of nuts arranged opposite to the side of the first through holes away from the cavities; a plurality of fastening screws having head portions and pin portions connected in sequence, the head portions of the fastening screws being stopped at the bottoms of the resonant holes, the pin portions of the fastening screws being arranged in the second through holes and the first through holes in sequence and being threadedly connected with the nuts; the head portions of the fastening screws have at least one corner portion in the circumferential direction thereof, the bottoms of the resonant holes are provided with limiting grooves for limiting and accommodating the head portions of the fastening screws, and the fastening screws can drive the resonant rods to rotate synchronously so that the distances between at least parts of the resonant rods and the coupling windows arranged on one side of the resonant rods are changed.

2. The filter of claim 1, wherein, The resonant rods comprise rod portions and disc portions connected in sequence, and the rod portions of the resonant rods have polygonal or special-shaped cross sections perpendicular to the axial directions thereof.

3. The filter of claim 1, wherein, The resonant rods are straight rods, and the resonant rods have polygonal or special-shaped cross sections perpendicular to the axial directions thereof.

4. The filter of any one of claims 1-3, wherein, The first through holes are light holes.

5. The filter of any one of claims 1-3, wherein, The cover plate is provided with a first groove on the side thereof away from the cavities, and the bottom of the first groove forms a deformed portion, and the first through holes are arranged on the deformed portion.

6. The filter of claim 5, wherein, The cover plate is provided with a second groove on the side thereof away from the cavities, and the groove bottom of the second groove is provided with the first groove; The filter further comprises at least one elastic sheet, the circumferential edge of the elastic sheet elastically abutting against the groove wall of the second groove, the middle portion of the elastic sheet being provided with a third through hole for the pin portion of the fastening screw to pass through, and the middle portion of the elastic sheet elastically abutting against the nut.

7. The filter of claim 5, wherein, The deformed portion is provided with a boss, and the first through holes are arranged on the boss.

8. The filter of any one of claims 1-3, wherein, The filter further comprises at least one elastic sheet arranged on the side of the cover plate facing the cavities, the circumferential edge of the elastic sheet elastically abutting against the cover plate, the middle portion of the elastic sheet being provided with a third through hole for the pin portion of the fastening screw to pass through, and the middle portion of the elastic sheet elastically abutting against the resonant rod.

9. The filter of claim 8, wherein, The side of the cover plate facing the cavities is provided with a third groove, and the circumferential edge of the elastic sheet elastically abuts against the groove wall of the third groove.

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