Low-frequency cavity filter

Abstract

The utility model discloses a low-frequency cavity filter, which relates to the technical field of filters, and comprises a cavity, a resonance inner cavity is formed in the cavity, and a resonator is inserted in the resonance inner cavity. The resonator is composed of a resonance column fixedly connected with the bottom of the cavity and two resonance discs coaxial with the resonance column, a coupling capacitor is formed between the resonance disc located at the upper end and the top of the cavity, and a coupling capacitor is formed between the two resonance discs. According to the utility model, the two inductance structures are formed between the two resonance discs and the resonance column, and the effects of increasing the inductance value and reducing the frequency are realized when the diameters of the resonance discs are increased; meanwhile, a coupling capacitor is formed between the resonance disc located on the upper side and the upper side of the cavity, and a coupling capacitor is formed between the two resonance discs, so that the low-frequency cavity filter achieves the purposes of reducing the frequency and reducing the boundary dimension and the weight in a balanced mode at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of filters, and more specifically to a low-frequency cavity filter. Background Art

[0002] In certain communication fields, lower frequency cavity filters are required.

[0003] The product dimensions of cavity filters generally require small size and light weight. However, under current technical conditions, it is difficult to achieve a balance between low frequency and volume. Therefore, it is difficult to meet the performance requirements of filters in the corresponding communication field, and there is room for improvement. Summary of the invention

[0004] In view of this, the purpose of this application is to provide a low-frequency cavity filter to achieve the purpose of reducing the size and weight while reducing the frequency. The specific scheme is as follows:

[0005] A low-frequency cavity filter comprises a cavity, wherein a resonant inner cavity is formed in the cavity, a resonator is inserted in the resonant inner cavity, the resonator consists of a resonant column fixedly connected to the bottom of the cavity and two resonant disks coaxial with the resonant column, a coupling capacitor is formed between the resonant disk located at the upper end and the top of the cavity, and a coupling capacitor is formed between the two resonant disks.

[0006] Preferably: the resonant disk consists of a resonant lower disk and a resonant upper disk, the resonant upper disk is used to control the inductance and frequency by adjusting the diameter, and the spacing from the resonant upper disk to the top of the cavity is used to adjust the capacitance and frequency; the resonant lower disk is used to control the inductance and frequency by adjusting the diameter, and the spacing from the resonant lower disk to the resonant upper disk is used to adjust the capacitance and frequency.

[0007] Preferably: a cover plate is provided on the top of the cavity, and a frequency tuning screw with a lower end inserted into the top opening of the resonant column is inserted into the cover plate.

[0008] Preferably, the frequency tuning screw is threadedly connected with a frequency tuning nut, the frequency tuning screw is threadedly connected to the cover plate, and the lower side of the frequency tuning nut is used to abut against the outer side wall of the cover plate.

[0009] Preferably: a frequency adjustment fixing column is provided at the bottom of the cavity, and a fixing screw threadedly connected to the frequency adjustment fixing column is inserted at the bottom of the resonator.

[0010] It can be seen from the above scheme that the present application provides a low-frequency cavity filter, which has the following beneficial effects: two inductance structures are formed by the two resonant disks and the resonant column, and when the diameter of the resonant disk increases, the effect of increasing the inductance and reducing the frequency is achieved; at the same time, a coupling capacitor is formed between the resonant disk located on the upper side and the upper side of the cavity, and the effect of increasing the capacitance and reducing the frequency is achieved by adjusting the spacing, and a coupling capacitor is formed between the two resonant disks to further adjust the capacitance size and frequency, so that the low-frequency cavity filter has the purpose of achieving a balanced reduction in size and weight while reducing the frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of this embodiment;

[0012] Figure 2 It is a schematic cross-sectional structural diagram of this embodiment.

[0013] Explanation of the accompanying drawings: 1. Cavity; 11. Resonant inner cavity; 12. Frequency adjustment fixing column; 2. Cover plate; 3. Frequency tuning screw; 4. Frequency tuning nut; 5. Resonator; 51. Resonant lower plate; 52. Resonant upper plate; 53. Resonant column; 6. Fixing screw. DETAILED DESCRIPTION

[0014] In order to make the technical solution and advantages of the utility model clearer, the utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0015] like Figure 1 As shown, a low-frequency cavity 1 filter comprises a cavity 1. The cavity 1 is cylindrical, so as to achieve an effective filtering function through the internal structure.

[0016] like Figure 1 , Figure 2 As shown, a resonant cavity 11 is formed inside the cylindrical cavity 1. In order to achieve an effective filtering function, a resonator 5 is plugged into the resonant cavity 11. The resonator 5 consists of a resonant column 53 fixedly connected to the bottom of the cavity 1 and two resonant disks coaxial with the resonant column 53. Among them, a coupling capacitor is formed between the resonant disk at the upper end and the top of the cavity 1, and a coupling capacitor is formed between the two resonant disks. At the same time, two electrical structures will be realized in the resonator 5, and the inductance and frequency can be effectively adjusted and controlled according to the diameter of different resonant disks.

[0017] It should be noted that the resonant disk is a resonant lower disk 51 and a resonant upper disk 52. The resonant upper disk 52 is used to control the inductance and frequency by adjusting the diameter, and the spacing from the resonant upper disk 52 to the top of the cavity 1 is used to adjust the capacitance and frequency. The resonant lower disk 51 is used to control the inductance and frequency by adjusting the diameter, and the spacing from the resonant lower disk 51 to the resonant upper disk 52 is used to adjust the capacitance and frequency.

[0018] like Figure 1 , Figure 2 As shown, a cover plate 2 is provided at the top of the cavity 1. The cover plate 2 is detachably connected and fixed to the cavity 1, thereby achieving the purpose of reducing the difficulty of assembly. A frequency tuning screw 3 whose lower end is inserted into the top opening of the resonant column 53 is inserted into the axial part of the cover plate 2, so that the frequency tuning screw 3, the resonator 5 and the cavity 1 cooperate with each other to achieve an effective filtering function. In order to further adjust the filtering frequency, a frequency tuning nut 4 is threadedly connected to the frequency tuning screw 3. Among them, the frequency tuning screw 3 is threadedly connected to the cover plate 2, and the lower side of the frequency tuning nut 4 is used to abut against the outer wall of the cover plate 2, thereby significantly improving the connection stability between the frequency tuning screw 3 and the cover plate 2, so as to further improve the matching stability between the frequency tuning screw 3 and the resonator 5. It should be noted that a frequency adjustment fixing column 12 is provided at the bottom of the cavity 1, and a fixing screw 6 threadedly connected to the frequency adjustment fixing column 12 is inserted at the bottom of the resonator 5. Therefore, the fixing screw 6, the frequency adjustment fixing column 12 and the resonator 5 cooperate with each other to form a stable connection structure, and achieve the purpose of low-frequency filtering while optimizing the structure to reduce the volume.

[0019] In summary, the present application provides a low-frequency cavity 1 filter, which forms two inductance structures through the two resonant disks and the resonant column 53, and achieves the effect of increasing inductance and reducing frequency when the diameter of the resonant disk increases; at the same time, a coupling capacitor is formed between the resonant disk located on the upper side and the upper side of the cavity 1, and the effect of increasing capacitance and reducing frequency is achieved by adjusting the spacing, and a coupling capacitor is formed between the two resonant disks to further adjust the capacitance size and frequency, so that the low-frequency cavity 1 filter has the purpose of achieving a balanced reduction in size and weight while reducing the frequency.

[0020] The "first", "second", "third", "fourth", etc. (if any) referred to in this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods or devices.

[0021] It should be noted that the descriptions involving "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0022] Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A low-frequency cavity (1) filter, comprising a cavity (1), wherein a resonant inner cavity (11) is formed in the cavity (1), and a resonator (5) is plugged into the resonant inner cavity (11), characterized in that: The resonator (5) is composed of a resonant column (53) connected and fixed to the bottom of the cavity (1) and two resonant disks coaxial with the resonant column (53), a coupling capacitor is formed between the resonant disk located at the upper end and the top of the cavity (1), and a coupling capacitor is formed between the two resonant disks.

2. A low-frequency cavity (1) filter according to claim 1, characterized in that: The resonant disk comprises a resonant lower disk (51) and a resonant upper disk (52); the resonant upper disk (52) is used to control inductance and frequency by adjusting the diameter, and the distance between the resonant upper disk (52) and the top of the cavity (1) is used to adjust capacitance and frequency; the resonant lower disk (51) is used to control inductance and frequency by adjusting the diameter, and the distance between the resonant lower disk (51) and the resonant upper disk (52) is used to adjust capacitance and frequency.

3. A low-frequency cavity (1) filter according to claim 1, characterized in that: A cover plate (2) is provided on the top of the cavity (1), and a frequency tuning screw (3) is inserted into the cover plate (2), the lower end of which is inserted into the top opening of the resonant column (53).

4. A low-frequency cavity (1) filter according to claim 3, characterized in that: The frequency tuning screw (3) is threadedly connected to a frequency tuning nut (4), the frequency tuning screw (3) is threadedly connected to the cover plate (2), and the lower side of the frequency tuning nut (4) is used to abut against the outer side wall of the cover plate (2).

5. A low-frequency cavity (1) filter according to claim 1, characterized in that: A frequency adjustment fixing column (12) is provided at the bottom of the cavity (1), and a fixing screw (6) threadedly connected to the frequency adjustment fixing column (12) is inserted into the bottom of the resonator (5).

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