Broadband band-pass filter for improving right-end suppression

Abstract

The utility model discloses a broadband band-pass filter capable of improving right-end suppression. The filter comprises a cavity and a cover plate, wherein the cover plate is fixedly arranged on the cavity; a plurality of resonators are fixedly installed in the cavity, and two dumbbell-shaped flying rods and two protruding connecting ends are further installed in the cavity. A plurality of frequency tuning assemblies, a plurality of main coupling tuning assemblies and four cross coupling tuning assemblies are mounted on the cover plate, each frequency tuning assembly is electrically connected with each resonator, and two cross coupling tuning assemblies are electrically connected with two dumbbell-shaped flying rods; and the other two cross coupling tuning assemblies are loaded with coiled screw fly rods and are electrically connected with the two connecting ends respectively. According to the broadband band-pass filter for improving right-end suppression, the advantages of a common dumbbell-shaped flying rod and a metal belt disc screw flying rod are combined together, left-end high suppression is met, high-end resonance suppression can be improved, the size and insertion loss are small, and the bearing power is large.

Description

Technical Field

[0001] This utility model relates to the field of filters, and in particular to a broadband bandpass filter with improved right-end suppression. Background Technology

[0002] With its advantages of small size, low insertion loss, high suppression, and low cost, the wide operating bandwidth bandpass filter will become the mainstream application solution to replace the traditional coaxial cavity filter in the future.

[0003] To meet the requirements of communication systems, ordinary coaxial broadband bandpass filters need high suppression on the left side, which is often achieved by adding multiple dumbbell-shaped flybar structures. However, multiple dumbbell flybars will resonate at the high end of the passband, and because the resonance is very close to the passband, the high-end suppression of the filter will deteriorate. At this point, it is difficult to meet the suppression requirements by connecting a low-pass filter in series. Even if it can barely meet the requirements, the introduction of a low-pass filter will lead to a larger product size, increased insertion loss, reduced power handling, and greater impact from manufacturing quality factors. This not only greatly reduces the performance of the filter but also increases the manufacturing cost of the filter. Utility Model Content

[0004] To address the aforementioned issues, this invention provides a broadband bandpass filter that improves right-end suppression. It combines the advantages of both a standard dumbbell-shaped flyrod and a metal disc screw flyrod, thus satisfying both high left-end suppression and improving high-end resonance suppression. It also features small size, low insertion loss, high power handling capacity, and low cost.

[0005] According to one aspect of the present invention, a broadband bandpass filter with improved right-end suppression is provided, comprising a cavity and a cover plate, the cover plate being fixedly mounted on the cavity; a plurality of resonators are fixedly mounted inside the cavity, some of the resonators being coupled and connected to each other by a plurality of coupling ribs, and two dumbbell-shaped flying rods and two protruding connecting ends are also mounted inside the cavity;

[0006] The cover plate is equipped with multiple frequency tuning components, multiple main coupling tuning components, and four cross-coupling tuning components. Each frequency tuning component is electrically connected to each resonator. Each main coupling tuning component is distributed among the frequency tuning components. Two of the cross-coupling tuning components are electrically connected to two dumbbell-shaped fly rods. The other two cross-coupling tuning components are each loaded with a disc screw fly rod and are electrically connected to two connection ends.

[0007] The disc-type screw fly rod includes a metal screw, one end of which forms a resonant disk.

[0008] In some embodiments, the cavity is made of aluminum. The advantage of this is that it describes a suitable material for the cavity.

[0009] In some embodiments, each of the resonators is made of Invar steel. The advantage of this is that it describes suitable materials for the resonators.

[0010] In some embodiments, the cavity contains two support seats, and the two dumbbell-shaped booms are respectively engaged and mounted on the two support seats. The advantage is that it describes a specific method of mounting the two dumbbell-shaped booms inside the cavity.

[0011] In some embodiments, the cavity is further fitted with two coaxial connectors extending to the outside, wherein the two resonators are respectively connected to the two coaxial connectors extending to the cavity via two input / output coupling plates. This has the advantage of further refining the cavity structure.

[0012] In some embodiments, the two ends of the input / output coupling plate are soldered to the resonator and the coaxial connector, respectively. The advantage is that it further describes the specific connection method of the input / output coupling plate, the resonator, and the coaxial connector. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the cavity structure of a broadband bandpass filter with improved right-end suppression according to one embodiment of the present invention;

[0014] Figure 2 for Figure 1 The diagram shows a cover plate structure for a broadband bandpass filter that improves right-end suppression.

[0015] Figure 3 for Figure 2 The diagram shows the structure of a metal screw flybar with a disc.

[0016] In the figure: cavity 1, cover plate 2, screw fly rod with disc 3, resonator 11, coupling rib 12, dumbbell-shaped fly rod 13, connecting end 14, support base 15, coaxial connector 16, coupling plate 17, frequency tuning component 21, main coupling tuning component 22, cross coupling tuning component 23, metal screw 31, resonant disk 32. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings.

[0018] like Figure 1-3 As shown, the filter includes a cavity 1 and a cover plate 2, wherein the cover plate 2 is mounted on the top of the cavity 1 and is electrically connected to the cavity 1.

[0019] like Figure 1 As shown, multiple protruding resonators 11 are fixedly installed inside the cavity 1, and some of the resonators 11 are coupled to each other through multiple coupling ribs 12. Two coaxial connectors 16 extending to the outside of the cavity 1 are fixedly installed at both ends of the cavity 1, and the two coaxial connectors 16 are respectively welded to two of the resonators 11 located at both ends inside the cavity 1 through two input / output coupling plates 17.

[0020] Preferably, the cavity 1 is made of aluminum, while each resonator 11 is made of Invar steel.

[0021] In addition, two support seats 15 are provided inside part of the cavity 1, and two dumbbell-shaped flying rods 13 are respectively engaged and installed on each support seat 15.

[0022] When assembling cavity 1, each resonator 11 is installed inside cavity 1. Then, two coaxial connectors 16 are fixed to both ends of cavity 1 with screws. Then, one end of each of the two input / output coupling plates 17 is welded to one of the two resonators 11 respectively, and the other end is welded to the two coaxial connectors 16 respectively. Then, each resonator 11 is fixedly installed with screws. Finally, each dumbbell-shaped flying rod 13 is clipped onto each support base 15.

[0023] like Figure 2-3 As shown, multiple tuning components are installed on the cover plate 2, including multiple frequency tuning components 21, multiple main coupling tuning components 22 and four cross coupling tuning components 23.

[0024] The number of frequency tuning components 21 is the same as the number of resonators 11 in cavity 1. The number of main coupling tuning components 22 is close to or the same as the number of frequency tuning components 21, and they are distributed among the frequency tuning components 21. When the cover plate 2 is placed on cavity 1, each frequency tuning component 21 is electrically connected to each resonator 11, and two of the four cross-coupled tuning components 23 are electrically connected to two dumbbell-shaped flying rods 13.

[0025] In addition, such as Figure 1-3 As shown, two of the four cross-coupled tuning components 23 are each loaded with a disc-shaped screw flyrod 3. This disc-shaped screw flyrod 3 is composed of a common metal screw 31 with one end thickened to form a resonant disk 32, and two corresponding protruding connecting ends 14 are provided inside the cavity 1. When the cover plate 2 is placed on the cavity 1, the two disc-shaped screw flyrods 3 are electrically connected to the two connecting ends 14 respectively.

[0026] Since the characteristics of a bandpass filter are mainly used to filter out suppression outside the passband, in some special cases, it is necessary to use multiple flybar structures to generate multiple transmission zeros on the left side to meet the strict suppression at the left end of the passband. Traditional filters only use dumbbell-shaped flybars 13. Although they meet the strict suppression at the left side of the passband, the flybars will generate multiple resonances at frequencies very close to the right end of the passband, resulting in lower suppression at the right end of the passband, which greatly reduces the suppression characteristics of the filter.

[0027] The filter in this invention adds a loaded disk-type metal screw 31 flybar 3, one end of which is thickened to form a resonant disk 32, thereby lowering the frequency and ensuring that the second resonant frequency of the cross-coupling structure is at the lower end of the passband, achieving a left-end zero. Simultaneously, the structure of the disk-type metal screw 31 flybar 3 also generates a resonant frequency at the lower end of the passband, which is the first resonant frequency of the coupling structure. This achieves both suppression at the left end of the passband and improved suppression at the right end.

[0028] The above descriptions are merely some embodiments of this utility model. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this utility model, and all such modifications and improvements fall within the protection scope of this utility model.

Claims

1. A broadband bandpass filter with improved right-end suppression, characterized in that: It includes a cavity (1) and a cover plate (2), the cover plate (2) being fixedly installed on the cavity (1); multiple resonators (11) are fixedly installed inside the cavity (1), some of the resonators (11) are coupled and connected to each other by multiple coupling ribs (12), and two dumbbell-shaped flying rods (13) and two protruding connecting ends (14) are also installed inside the cavity (1); The cover plate (2) is equipped with multiple frequency tuning components (21), multiple main coupling tuning components (22) and four cross coupling tuning components (23). Each frequency tuning component (21) is electrically connected to each resonator (11). Each main coupling tuning component (22) is distributed between each frequency tuning component (21). Two of the cross coupling tuning components (23) are electrically connected to two dumbbell-shaped flying rods (13). The other two cross coupling tuning components (23) are loaded with disc screw flying rods (3) and are electrically connected to two connection ends (14). The screw fly rod (3) with a disc includes a metal screw (31), one end of which forms a resonant disk (32).

2. A broadband bandpass filter with improved right-end suppression according to claim 1, characterized in that: The cavity (1) is made of aluminum.

3. A broadband bandpass filter with improved right-end suppression according to claim 1, characterized in that: Each of the resonators (11) is made of Invar steel.

4. A broadband bandpass filter with improved right-end suppression according to claim 1, characterized in that: The cavity (1) is provided with two support seats (15), and the two dumbbell-shaped flying rods (13) are respectively engaged and installed on the two support seats (15).

5. A broadband bandpass filter with improved right-end suppression according to claim 1, characterized in that: The cavity (1) is also equipped with two coaxial connectors (16) extending to the outside, wherein the two resonators (11) are respectively connected to the two coaxial connectors (16) extending to the cavity (1) through two input-output coupling plates (17).

6. A broadband bandpass filter with improved right-end suppression according to claim 5, characterized in that: The two ends of the input / output coupling plate (17) are respectively welded to the resonator (11) and the coaxial connector (16).

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