A low-frequency cavity filter based on interdigital variable-phase zero

Abstract

The utility model discloses a low -frequency cavity filter based on interdigital variable phase zero point belongs to cavity filter technical field, including the cavity, be provided with at least one support vertical board in the cavity, the resonator, the resonator number is multiple and present detachable installation in the cavity, the resonator presents a character arrangement in the cavity, and is supported installation by support vertical board, and the interdigital variable phase zero point structure is formed between adjacent resonator, the tuning screw, the tuning screw is installed in the resonator end, with the adjustment resonator's resonant frequency, the joint, the joint is installed in the cavity end, with filter and external radio frequency circuit connection. The utility model's filter adopts cavity and resonator and carries out split assembly, and the loading installation of cooperation tuning screw is realized the resonant coverage of low frequency band, and the resonator under the layout of a character type row cavity adopts the interdigital variable phase design, and the magnetic coupling is converted for electric coupling, and the production process difficulty is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of cavity filter technology, and in particular relates to a low-frequency cavity filter based on interdigital phase zero. Background Technology

[0002] In radio frequency communication systems, filters are critical passive components used to filter signals within a specific frequency range and suppress interference signals. Cavity filters, due to their advantages such as high Q value and high power capacity, are widely used in communication base stations, microwave equipment, and other fields. However, for low-frequency filtering requirements, traditional cavity filters suffer from problems such as complex structure, difficult debugging, and low production operability. Especially when achieving a zero point (transmission zero) to improve out-of-band rejection performance, the high debugging precision required for magnetic coupling methods is not conducive to mass production. Therefore, there is an urgent need for a low-frequency cavity filter based on interdigital phase-shifted zeros. Utility Model Content

[0003] This invention overcomes the shortcomings of the prior art by providing a low-frequency cavity filter based on interdigital phase zero, thereby solving the problems existing in the prior art.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is: a low-frequency cavity filter based on interdigital phase zero, comprising... The cavity contains at least one supporting plate. The resonators are multiple and detachably installed in the cavity. The resonators are arranged in a straight line in the cavity and supported by the support plate. An interdigital phase-zero structure is formed between adjacent resonators. A tuning screw, which is mounted on the end of the resonator, to adjust the resonant frequency of the resonator; A connector is mounted at the end of the cavity to connect the filter to an external radio frequency circuit.

[0005] In a preferred embodiment of the present invention, the support plate is arranged along the length direction of the cavity, and the support plate is provided with an annular groove to support and install the resonator.

[0006] In a preferred embodiment of this utility model, the resonator is a metal cylindrical structure, and both ends of the resonator are mounted using the tuning screws.

[0007] In a preferred embodiment of the present invention, the cavity has an embedding hole on its side, and the tuning screw is located in the embedding hole.

[0008] In a preferred embodiment of this utility model, a cover plate is provided on the opening side of the cavity, and the cover plate is connected to the cavity by a number of locking screws.

[0009] In a preferred embodiment of this utility model, the cavity is provided with a plurality of slots to house the resonators in a straight line within the cavity.

[0010] In a preferred embodiment of this utility model, the cavity is an aluminum alloy structural component or a copper component.

[0011] This utility model solves the defects existing in the background technology, and has the following beneficial effects: The filter of this utility model adopts separate assembly of cavity and resonator, and is loaded and installed with tuning screws, which realizes resonance coverage in the low frequency band. The structural design is flexible and easy to adjust the frequency. The resonator under the one-line cavity layout adopts interdigital phase-changing design, which converts magnetic coupling into electrical coupling, reduces the difficulty of production process, improves manufacturability, and is conducive to mass production. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a schematic diagram of the overall structure of a preferred embodiment of the present invention; Figure 2 This is a partial structural schematic diagram of a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the cavity structure in a preferred embodiment of the present invention; Figure 4 This is a schematic diagram of the supporting plate of a preferred embodiment of the present invention; In the diagram: 10, cavity; 101, embedding hole; 102, partition groove; 11, support plate; 111, annular slot; 20, resonator; 30, tuning screw; 40, connector; 50, cover plate; 60, locking screw. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0014] This embodiment provides a low-frequency cavity filter based on interdigital phase-zero. The filter is assembled separately with cavity 10 and resonator 20, and loaded with tuning screws 30. It achieves resonance coverage in the low-frequency band. The structure design is flexible and easy to tune the frequency. The resonator 20 in the linear cavity layout adopts an interdigital phase-zero design, which converts magnetic coupling into electrical coupling, reduces the difficulty of the manufacturing process, improves manufacturability, and is conducive to mass production.

[0015] Combination Figures 1 to 4As shown in the figure, the low-frequency cavity filter based on interdigital phase-zero technology proposed in this embodiment comprises several key components, including a cavity 10, a resonator 20, a tuning screw 30, and a connector 40. The cavity 10, as the core support and shielding structure of the entire filter system, is typically made of highly conductive metal material through precision machining. It not only possesses excellent mechanical strength but also effectively isolates external electromagnetic interference, providing a highly stable and clean electromagnetic working environment for the internal resonant units. The resonator 20, as the core component for implementing the filtering function, utilizes its special interdigital structure design to generate the required phase-zero in the low-frequency range, thereby significantly improving the frequency selectivity of the filter and ensuring high accuracy and transmission stability of the signal during processing. The tuning screw 30 is mounted on the cavity 10 and used for fine adjustment of the resonant frequency. By rotating the tuning screw 30, the electromagnetic coupling state between the resonators 20 can be changed, thereby optimizing the filter's passband characteristics, stopband suppression, and zero-point position. Connector 40 serves as the input and output port for radio frequency signals. It adopts a widely compatible standard interface, which not only facilitates reliable connection with other devices in the system, but also ensures low insertion loss and good impedance matching during signal transmission, thereby supporting the efficient operation and overall compatibility of the entire communication system.

[0016] In this embodiment, the internal structure of the cavity 10 is carefully designed and optimized, including at least one longitudinally arranged support plate 11. This support plate 11 is strictly fixed vertically along the length of the cavity 10, providing stable and reliable mechanical support for the entire cavity 10 structure, ensuring structural integrity under mechanical vibration or external stress. Furthermore, multiple resonators 20 are configured, arranged detachably within the cavity 10, greatly facilitating subsequent maintenance and component replacement. The multiple resonators 20 are uniformly arranged in a straight line within the cavity 10, with a neat and orderly overall layout. The spacing between adjacent resonators 20 remains consistent, contributing to a uniform distribution of electromagnetic performance. Each resonator 20 is firmly supported and precisely installed via the support plate 11, effectively preventing positional shift or loosening.

[0017] Between two adjacent resonators 20, a special structure called an interdigital phase zero is formed through a scientifically designed spatial layout and precise electromagnetic coupling. This structure significantly improves the frequency selectivity of the filter and enhances its ability to suppress stopband signals, thereby optimizing the overall filtering performance. Furthermore, tuning screws 30 are precisely installed at the end of each resonator 20. By rotating and adjusting these screws, the physical length or capacitance parameters of the resonator 20 can be finely adjusted, thus achieving precise adjustment of the resonant frequency of a single resonator 20 to meet different frequency response requirements. Simultaneously, a connector 40 is securely installed at one end of the cavity 10. Its interface design fully considers compatibility with external RF circuits, enabling a reliable connection between the filter and the system circuit, ensuring high efficiency and stability in signal transmission.

[0018] Specifically, in this embodiment, the support plate 11 is precisely arranged and reliably fixed along the length of the cavity 10. Its installation position and spatial orientation have been rigorously calculated and optimized to ensure excellent stability of the overall structure under both dynamic and static loads, and to effectively guarantee the accurate realization of the filter function. Furthermore, the support plate 11 is also provided with a regular-shaped and precisely sized annular slot 111. The structural parameters of this slot are perfectly matched with the shape and installation requirements of the resonator 20, which can stably support and firmly lock the resonator 20, thereby significantly improving the reliability of its mechanical installation throughout the entire operation of the filter and ensuring the long-term accuracy and consistency of its electrical performance.

[0019] Combination Figure 1 and Figure 2 As shown, the resonator 20 proposed in this embodiment adopts a cylindrical structure made of metal. This design choice not only significantly improves the overall mechanical stability and structural strength of the resonator 20, but also enables effective performance optimization and control in terms of electromagnetic characteristics. Both ends of the resonator 20 are securely mounted using precision-designed tuning screws 30. This fixing method ensures that the resonator 20 maintains precise positioning during operation and maintains a high degree of stability in its frequency output. In addition, multiple insertion holes 101 are specially designed and machined on the side of the cavity 10. The tuning screws 30 are appropriately installed inside these pre-set insertion holes 101. This layout fully considers the convenience and operational efficiency during actual assembly, and further enhances the structural coordination and integrity of the entire resonator 20.

[0020] Furthermore, the cavity 10 is internally designed with multiple neatly arranged slots 102. These slots 102 serve to arrange and fix the various resonators 20 in a straight line within the cavity 10, thereby achieving efficient space utilization and optimized signal transmission paths. The cavity 10 itself is made of highly conductive and thermally conductive materials, specifically aluminum alloy structural components or copper components, to meet the stringent requirements for heat dissipation and electrical performance in high-frequency applications.

[0021] Furthermore, a cover plate 50 is provided on the opening side of the cavity 10 to provide sealing and protection functions. The cover plate 50 is tightly connected to the side of the cavity 10 by multiple locking screws 60 to ensure structural stability and prevent external impurities from entering the internal space.

[0022] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A low-frequency cavity filter based on interdigital phase-zero shift, characterized in that, include A cavity (10) is provided with at least one supporting plate (11); The resonator (20) is a plurality of resonators and is detachably installed in the cavity (10). The resonators (20) are arranged in a line in the cavity (10) and are supported by the support plate (11). An interdigital phase zero structure is formed between adjacent resonators (20). A tuning screw (30) is mounted on the end of the resonator (20) to adjust the resonant frequency of the resonator (20); A connector (40) is mounted at the end of the cavity (10) to connect the filter to an external radio frequency circuit.

2. A low-frequency cavity filter based on interdigital phase-zero as described in claim 1, characterized in that, The support plate (11) is arranged along the length of the cavity (10), and the support plate (11) is provided with an annular groove (111) to support and install the resonator (20).

3. A low-frequency cavity filter based on interdigital phase-zero as described in claim 1, characterized in that, The resonator (20) is a metal cylindrical structure, and both ends of the resonator (20) are mounted with the tuning screws (30).

4. A low-frequency cavity filter based on interdigital phase-zero as described in claim 1 or 3, characterized in that, The cavity (10) has an embedding hole (101) on its side, and the tuning screw (30) is located in the embedding hole (101).

5. A low-frequency cavity filter based on interdigital phase-zero as described in claim 1, characterized in that, The cavity (10) has a cover plate (50) on the opening side, and the cover plate (50) is connected to the cavity (10) by a number of locking screws (60).

6. A low-frequency cavity filter based on interdigital phase-zero as described in claim 1, characterized in that, The cavity (10) is provided with a plurality of partitions (102) to install the resonator (20) in a line arrangement inside the cavity (10).

7. A low-frequency cavity filter based on interdigital phase-zero as described in claim 1, characterized in that, The cavity (10) is an aluminum alloy structural component or a copper component.

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