Cross coupling structure of cavity filter

Abstract

The utility model discloses a cross coupling structure of a cavity filter, which comprises a filter main body, a cavity is formed in the filter main body, and a plurality of resonators are arranged in the cavity at intervals along the length direction; a coupling rib is connected between the resonators, a coupling sheet is arranged in the cavity, the two ends of the coupling sheet are respectively locked on the resonators close to the two ends of the cavity, and a dielectric gasket made of an insulating material is arranged between the coupling sheet and the resonators, so that capacitive coupling is formed between the resonators connected with the coupling sheet.

Description

Technical Field

[0001] The utility model relates to the technical field of filters, and particularly relates to a cross-coupling structure of a cavity filter. Background Art

[0002] The internal structure of a cavity filter usually consists of a group of resonant cavities. Each cavity contains one or more resonators, and their shapes, sizes, and positions are determined according to design requirements. Common cavity structures include cylindrical, rectangular, and spherical shapes, etc., among which the cylindrical cavity is the most common.

[0003] The existing straight rectangular cavities cannot perform cross-coupling, resulting in a reduction in the electrical performance indicators of the product, thereby reducing the competitiveness of the product. Summary of the Utility Model

[0004] To solve the technical problems in the background art, the utility model proposes a cross-coupling structure of a cavity filter.

[0005] The technical solution adopted by the utility model to solve its technical problems is as follows:

[0006] A cross-coupling structure of a cavity filter includes a filter main body. A cavity is formed in the filter main body, and a plurality of resonators are arranged at intervals along the length direction in the cavity;

[0007] Coupling ribs are connected between the resonators, and a coupling sheet is arranged in the cavity. Both ends of the coupling sheet are locked on the resonators close to both ends of the cavity, and a dielectric gasket made of an insulating material is arranged between the coupling sheet and the resonator, so that capacitive coupling is formed between the resonators connected by the coupling sheet.

[0008] Preferably, the cavity is rectangular. Through the above improvement, the cavity is set to be rectangular, and the resonators are arranged at equal intervals along the length direction in the cavity. Through the coupling sheet and the coupling ribs, a coupling relationship is formed between the resonators, thereby ensuring the electrical performance indicators in a limited space, reducing the volume of the product, and greatly improving the competitiveness of the product.

[0009] Preferably, the resonator includes a first resonator, a second resonator, and a third resonator that are spaced along the length direction of the cavity, and both ends of the coupling sheet are respectively fixed on the first resonator and the third resonator. Through the above improvement, the first resonator, the second resonator, and the third resonator are connected by coupling ribs, and both ends of the coupling sheet are respectively connected to the first resonator and the third resonator, so that a coupling relationship is formed between the resonators, thereby increasing the electrical performance indicators of the product.

[0010] Preferably, a defining convex portion extending inward is formed on the inner wall of the cavity, so that several communicating resonant cavities are defined in the cavity, and the resonators are respectively placed in the resonant cavities. Through the above improvement, the resonators are respectively placed in the resonant cavities, and cross-coupling is realized in the straight row cavity through the coupling ribs and the coupling sheets.

[0011] Preferably, the number of the resonators is at least 3. Through the above improvement, the tuning function can be realized by arranging multiple resonators.

[0012] Preferably, a cover plate is provided on the top of the filter body, and several liftable tuning screws are provided on the cover plate. A part of the tuning screw is placed in the cavity, and the tuning screw is arranged opposite to the resonator. Through the above improvement, the resonator and the tuning screw are in one-to-one correspondence. The tuning screw can be rotated. The resonator includes a resonant cap and a resonant rod. There is a gap between the resonant rod and the cover plate to form a parallel plate capacitor. The size of the parallel plate capacitor can be changed by screwing the tuning screw in or out to realize the adjustment of the resonant frequency.

[0013] Preferably, a liftable coupling screw is further provided on the cover plate. A part of the coupling screw is placed in the cavity and is located between the resonators. Through the above improvement, the coupling screw is liftably arranged between the placed resonant cavities. Since the coupling sheet cooperates with the coupling screw to form a coupling capacitor, by adjusting the extending length of the coupling screw, the coupling amount can be finely adjusted, thereby finely adjusting the bandwidth of the filter.

[0014] Preferably, the coupling sheet is laterally locked on the resonator by a screw, and the screw is made of plastic. Through the above improvement, the coupling sheet is fixed by the screw, ensuring the stability of the connection of the coupling sheet. And the screw is made of plastic, ensuring capacitive coupling between the first resonator and the third resonator.

[0015] Preferably, a connecting convex portion is formed at the bottom of the cover plate, a connecting groove for placing the connecting convex portion is formed on the filter body, and sealing grooves are formed on both sides of the connecting groove. Sealing rings are arranged in the sealing grooves. The connecting convex portion is placed in the connecting groove and presses the sealing ring. Through the above improvement, the sealing performance of the connection between the cover plate and the filter body is improved.

[0016] Preferably, connecting lug ears are formed on both sides of the cover plate, threaded holes are formed in the connecting lug ears and the side part of the filter body, and connecting knobs are arranged on the connecting lug ears. The connecting knobs are in threaded connection with the threaded holes. Through the above improvement, it is more convenient to disassemble and install the cover plate and the filter body. Compared with the conventional locking with multiple screws, the time is greatly reduced.

[0017] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0018] By arranging a cavity with a straight-through arrangement inside the filter body, and arranging resonators at intervals along the length direction of the cavity, coupling ribs are connected between the resonators, and a coupling sheet is arranged inside the cavity. Both ends of the coupling sheet are locked on the resonators close to both ends of the cavity, so as to achieve cross-coupling in the straight-through cavity, thereby increasing the electrical performance indexes of the product. At the same time, the product volume is reduced under the same electrical performance, enhancing the competitiveness of the product. And a dielectric gasket made of an insulating material is arranged between the coupling sheet and the resonator, so that capacitive coupling is formed between the resonators connected by the coupling sheet, enhancing the anti-interference ability of the filter and ensuring the filtering effect. Description of the Drawings

[0019] Figure 1 It is a cross-sectional view of the overall structure of the present utility model;

[0020] Figure 2 It is a schematic structural view of the top of the overall structure of the present utility model;

[0021] Figure 3 It is a schematic structural view of the inside of the filter body of the present utility model;

[0022] Figure 4 It is a schematic structural view of the inside of the filter body of the present utility model from another angle;

[0023] Figure 5 It is a schematic view of the non-cross-coupling test result of the present utility model;

[0024] Figure 6 It is a schematic view of the capacitive cross-coupling test result of the present utility model;

[0025] Figure 7 It is a schematic structural view of the cooperation between the filter body and the cover plate in the second embodiment of the present utility model;

[0026] Figure 8 It is a cross-sectional view of the cooperation between the filter body and the cover plate in the second embodiment of the present utility model;

[0027] Figure 9 For the present utility model Figure 7 Partial enlarged view at A;

[0028] In the figure: 1. Filter body; 2. Cavity; 3. Resonator; 4. Coupling rib; 5. Coupling sheet; 6. Dielectric gasket; 7. First resonator; 8. Second resonator; 9. Third resonator; 10. Defining convex part; 11. Resonant cavity; 12. Cover plate; 13. Tuning screw; 14. Coupling screw; 15. Screw; 101. Connecting convex part; 102. Connecting groove; 103. Sealing groove; 104. Sealing ring; 105. Connecting lug; 106. Threaded hole; 107. Connecting knob; Detailed implementation mode

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0030] It should be understood that although terms such as upper, middle, lower, top, one end, etc. appear in this article to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish elements from each other for easy understanding, rather than to define any directional or sequential limitations.

[0031] Embodiment 1

[0032] As Figures 1-6 shown, a cross-coupling structure of a cavity 2 filter includes a filter body 1. A cavity 2 is formed in the filter body 1, and a plurality of resonators 3 are arranged at intervals along the length direction in the cavity 2.

[0033] Furthermore, coupling ribs 4 are connected between the resonators 3, and a coupling sheet 5 is arranged in the cavity 2. Both ends of the coupling sheet 5 are respectively locked on the resonators 3 near both ends of the cavity 2, and a dielectric gasket 6 made of an insulating material is arranged between the coupling sheet 5 and the resonators 3, so that capacitive coupling is formed between the resonators 3 connected by the coupling sheet 5, and it is locked on the resonators 3 with plastic screws 15.

[0034] By arranging the resonators 3 at intervals along the length direction of the cavity 2, coupling ribs 4 are connected between the resonators 3, and a coupling sheet 5 is arranged in the cavity 2. Both ends of the coupling sheet 5 are respectively locked on the resonators 3 near both ends of the cavity 2, so as to achieve cross-coupling in a straight-through cavity, thereby increasing the electrical performance index of the product. At the same time, the product volume is reduced under the same electrical performance, improving the competitiveness of the product. And a dielectric gasket 6 made of an insulating material is arranged between the coupling sheet 5 and the resonators 3, so that capacitive coupling is formed between the resonators 3 connected by the coupling sheet 5, improving the anti-interference ability of the filter and ensuring the filtering effect.

[0035] Among them, the cavity 2 is arranged in a rectangular shape, and the resonators 3 are arranged at equal intervals along the length direction in the cavity 2. Through the coupling sheet 5 and the coupling ribs 4, a coupling relationship is formed between the resonators 3, thereby ensuring the electrical performance index in a limited space and reducing the product volume, greatly improving the competitiveness of the product.

[0036] As Figures 1-4As shown, for a further explanation of the implementation of the resonator 3 in this embodiment, wherein the resonator 3 includes a first resonator 7, a second resonator 8, and a third resonator 9 spaced along the length direction of the cavity 2, and both ends of the coupling sheet 5 are respectively fixed on the first resonator 7 and the third resonator 9.

[0037] The first resonator 7, the second resonator 8, and the third resonator 9 are connected by coupling ribs 4, and both ends of the coupling sheet 5 are respectively connected to the first resonator 7 and the third resonator 9, forming a coupling relationship between the resonators 3, thereby increasing the electrical performance indicators of the product.

[0038] Wherein, a defining convex portion 10 extending inward is formed on the inner wall of the cavity 2, so that a plurality of connected resonant cavities 11 are defined in the cavity 2, and the resonators 3 are respectively placed in the resonant cavities 11, and the resonators 3 are respectively placed in the resonant cavities 11, and cross-coupling is realized in the straight-through cavity through the coupling ribs 4 and the coupling sheet 5.

[0039] Preferably, the coupling sheet 5 is laterally locked on the resonator 3 by screws 15, and the screws 15 are made of plastic. Fixing the coupling sheet 5 with the screws 15 ensures the stability of the connection of the coupling sheet 5, and the screws 15 are made of plastic to ensure capacitive coupling between the first resonator 73 and the third resonator 93.

[0040] Preferably, the dielectric gasket 6 is made of ceramic or Teflon, thereby isolating the coupling sheet 5 from the resonator 3, so that the first resonator 7 and the third resonator 9 form capacitive coupling.

[0041] Preferably, the coupling sheet 5 is a silver-plated copper sheet to improve the capacitive coupling effect.

[0042] Preferably, the number of resonators 3 is at least 3, and the tuning function can be realized by respectively placing a plurality of resonators 3 in the resonators 3.

[0043] As Figures 1-4 As shown, for a further explanation of the implementation of the cover plate 12 in this embodiment, wherein a cover plate 12 is covered on the top of the filter body 1, and a plurality of liftable tuning screws 13 are arranged on the cover plate 12. A part of the tuning screw 13 is placed in the cavity 2, and the tuning screw 13 is disposed opposite to the resonator 3.

[0044] The resonators 3 are respectively arranged in the resonant cavities 11, and the resonators 3 correspond to the tuning screws 13 one by one. The tuning screw 13 can be rotated. The resonator 3 includes a mounting screw and a resonant rod. There is a gap between the resonant rod and the cover plate 12 to form a parallel-plate capacitor. The size of the parallel-plate capacitor can be changed by screwing in or out the tuning screw 13 to realize the adjustment of the resonant frequency.

[0045] In addition, a liftable coupling screw 14 is also provided on the cover plate 12. The coupling screw 14 is partially placed in the cavity 2 and is located between the resonators 3. The coupling screw 14 is liftably arranged between the resonant cavities 11. By adjusting the extending length of the coupling screw 14, the coupling amount can be finely adjusted, thereby finely adjusting the bandwidth of the filter.

[0046] Preferably, the coupling piece 5 is laterally locked on the resonator 3 by a screw 15, and the screw 15 is made of plastic. Fixing the coupling piece 5 with the screw 15 ensures the stability of the connection of the coupling piece 5, and the screw 15 made of plastic ensures that a capacitive coupling is formed between the first resonator 7 and the third resonator 9.

[0047] As Figures 5-6 shown, capacitive cross-coupling is carried out by using the resonator 3, so that the test value of the signal without cross-coupling at 2100 MHz is 14 dB, and the test value of the signal with capacitive cross-coupling is 62 dB, indicating that the anti-interference performance is significantly improved, thus ensuring the filtering effect of the filter.

[0048] Embodiment 2

[0049] As Figure 7 、 Figure 8 、 Figure 9 shown, the difference between this embodiment and Embodiment 1 is that a connecting convex portion 101 is formed at the bottom of the cover plate 12, a connecting groove 102 for the connecting convex portion 101 to be placed in is formed on the filter body 1, and sealing grooves 103 are formed on both sides of the connecting groove 102. A sealing ring 104 is arranged in the sealing grooves 103. When the connecting convex portion 101 is placed in the connecting groove 102, the connecting convex portion 101 will squeeze the sealing ring 104, so that the sealing ring 104 fills the gap between the cover plate 12 and the filter body 1, greatly improving the sealing performance.

[0050] In addition, connecting convex ears 105 are formed on both sides of the cover plate 12. Threaded holes 106 are formed between the connecting convex ears 105 and the side of the filter body 1, and a connecting knob 107 is arranged on the connecting convex ears 105. The connecting knob 107 is threadedly connected with the threaded hole 106, so that the cover plate 12 and the filter body 1 are locked together, improving the convenience of connecting and disassembling the cover plate 12 and the filter body 1.

[0051] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A cross-coupling structure of a cavity filter, characterized in that: It comprises a filter body (1), wherein a cavity (2) is formed in the filter body (1), and a plurality of resonators (3) are arranged at intervals along the length direction in the cavity (2); A coupling rib (4) is connected between the resonators (3), and a coupling plate (5) is arranged in the cavity (2), the two ends of the coupling plate (5) are respectively locked on the resonators (3) close to the two ends of the cavity (2), and a dielectric gasket (6) made of insulating material is arranged between the coupling plate (5) and the resonator (3), so that capacitive coupling is formed between the resonators (3) connected to the coupling plate (5).

2. The cross-coupling structure of a cavity filter according to claim 1, characterized in that: The cavity (2) is arranged in a rectangular shape.

3. The cross-coupling structure of a cavity filter according to claim 1, characterized in that: The resonator (3) comprises a first resonator (7), a second resonator (8), and a third resonator (9) which are spaced apart along the length direction of the cavity (2), and two ends of the coupling plate (5) are respectively fixed on the first resonator (7) and the third resonator (9).

4. The cross-coupling structure of a cavity filter according to claim 1, characterized in that: The inner wall of the cavity (2) is formed with a defining convex portion (10) extending inwardly, so that a plurality of interconnected resonant cavities (11) are defined in the cavity (2), and the resonators (3) are respectively placed in the resonant cavities (11).

5. The cross-coupling structure of a cavity filter according to claim 1, characterized in that: The number of the resonators (3) is at least 3.

6. The cross-coupling structure of a cavity filter according to claim 1, characterized in that: The top of the filter body (1) is covered with a cover plate (12), and a plurality of liftable tuning screws (13) are arranged on the cover plate (12); the tuning screws (13) are partially inserted into the cavity (2), and the tuning screws (13) are arranged opposite to the resonator (3).

7. The cross-coupling structure of a cavity filter according to claim 6, characterized in that: The cover plate (12) is also provided with a lifting coupling screw (14), and a portion of the coupling screw (14) is inserted into the cavity (2) and is located between the resonators (3).

8. The cross-coupling structure of a cavity filter according to claim 1, characterized in that: The coupling plate (5) is laterally locked on the resonator (3) by means of screws (15), and the screws (15) are made of plastic.

9. The cross-coupling structure of a cavity filter according to claim 6, characterized in that: A connecting protrusion (101) is formed at the bottom of the cover plate (12), a connecting groove (102) for the connecting protrusion (101) to be inserted is formed on the filter body (1), and sealing grooves (103) are formed on both sides of the connecting groove (102), a sealing ring (104) is arranged in the sealing groove (103), and the connecting protrusion (101) is inserted into the connecting groove (102) and squeezes the sealing ring (104).

10. The cross-coupling structure of a cavity filter according to claim 9, characterized in that: Connecting lugs (105) are formed on both sides of the cover plate (12), and threaded holes (106) are formed on the connecting lugs (105) and the sides of the filter body (1), and a connecting knob (107) is provided on the connecting lug (105), and the connecting knob (107) is threadedly connected to the threaded hole (106).

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