Low-frequency broadband filter

Abstract

The utility model relates to the technical field of communication equipment, and discloses a low-frequency broadband filter, which comprises a metal shell, a base is arranged in the metal shell, a resonator unit is arranged on the base, the resonator unit comprises a first resonator, a second resonator, a third resonator, a fourth resonator, a fifth resonator and a sixth resonator, and the first resonator, the second resonator, the third resonator, the fourth resonator, the fifth resonator and the sixth resonator are arranged on the base. A fly rod is arranged between the second resonator and the fourth resonator, a coupling disc is installed at one end of the fly rod, and an inductance piece is arranged between the fourth resonator and the sixth resonator. The flying rod is fixedly installed on the inner cavity wall of the metal shell through a fixing piece, the end, provided with a coupling disc, of the flying rod is arranged on the lower side of the fourth resonator, a certain distance is reserved between the coupling disc and the bottom side wall of the fourth resonator, the coupling disc is suspended under supporting of the flying rod, and a low-end zero point is formed. And two ends of the inductance sheet are respectively arranged on the lower sides of the fourth resonator and the sixth resonator to form a high-end zero point.

Description

Technical Field

[0001] The utility model relates to the technical field of communication equipment, in particular to a low-frequency broadband filter. Background Art

[0002] As a key component of mobile communication systems, cavity filters are widely used in various mobile communication systems. Commonly used filters have obvious coupling effects under high frequency and relatively narrow bandwidth conditions. The normal dumbbell-type coupling disk can adjust the coupling amount by changing the corresponding distance from the side wall of the resonator, or changing the height of the connecting ribs, thereby achieving the required strong and weak zero points and adjusting to meet the suppression requirements.

[0003] However, it is impossible to achieve strong suppression coupling for ultra-low frequencies such as 200~400MHz using conventional methods. Conventional capacitive coupling has a greater effect under high-frequency narrowband channel conditions, and the coupling is obvious. The zero point generated meets the required out-of-band suppression requirements. For some low-frequency channels that require stronger coupling, the zero point will be weak and cannot meet the suppression requirements. Therefore, those skilled in the art provide a low-frequency broadband filter to solve the problems raised in the above background technology. Utility Model Content

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of the prior art, the utility model provides a low-frequency broadband filter to solve the problem that conventional capacitive coupling has a greater effect under high-frequency narrowband channel conditions, the coupling is obvious, and the zero point generated meets the required out-of-band suppression requirements. For some low-frequency channels that require stronger coupling, the zero point will be weak and cannot meet the suppression requirements.

[0006] (II) Technical solution

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a low-frequency broadband filter, comprising a metal shell, a first connector is installed on one side of the metal shell, a second connector is installed on the other end of the metal shell, a base is installed in the inner cavity of the metal shell, a cover plate is arranged on the metal shell, a tuning screw is installed on the cover plate, a fixing screw is arranged on one side of the tuning screw, a resonator unit is arranged on the base, the resonator unit includes a first resonator, a second resonator, a third resonator, a fourth resonator, a fifth resonator and a sixth resonator, a flying rod is arranged between the second resonator and the fourth resonator, a coupling disk is installed on one end of the flying rod, and an inductor is arranged between the fourth resonator and the sixth resonator.

[0008] Preferably, one end of the flying rod is fixedly connected to the bottom side wall of the second resonator, the coupling disk is arranged below the fourth resonator, one end of the flying rod is bent upward and welded to the bottom side wall of the second resonator, and one end of the flying rod with the coupling disk is arranged on the lower side of the fourth resonator. A certain distance is left between the coupling disk and the bottom side wall of the fourth resonator, and it is suspended in the air under the support of the flying rod to form a low-end zero point.

[0009] Preferably, two ends of the inductor are fixedly connected to the inner cavity of the metal shell, and the two ends of the inductor are respectively arranged at the lower sides of the fourth resonator and the sixth resonator to form a high-end zero point.

[0010] Preferably, a fixing piece is provided on the flying rod, and the flying rod is installed with the inner cavity of the metal shell through the fixing piece, and the tuning screw passes through the cover plate and the resonator unit in sequence and is threadedly connected with the base, and the fixing screw passes through the cover plate and is connected with the fixing piece.

[0011] (III) Beneficial effects

[0012] Compared with the prior art, the utility model provides a low-frequency broadband filter, which has the following beneficial effects:

[0013] Through design, a flying rod is arranged between the second resonator and the fourth resonator, and the flying rod is fixedly installed with the inner cavity wall of the metal shell through a fixing part, a coupling disk is installed at one end of the flying rod, and one end of the flying rod is welded to the bottom side wall of the second resonator, and the end of the flying rod with the coupling disk is arranged on the lower side of the fourth resonator, and a certain distance is left between the coupling disk and the bottom side wall of the fourth resonator. It is suspended under the support of the flying rod to form a low-end zero point, and an inductor is arranged between the fourth resonator and the sixth resonator, and the two ends of the inductor are respectively arranged on the lower side of the fourth resonator and the sixth resonator to form a high-end zero point. This technical solution has little effect on the resonant frequency, is easy to adjust to achieve the strength of the zero point, and has a better out-of-band suppression effect on the low-bandwidth passband filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a three-dimensional structural schematic diagram of a low-frequency broadband filter provided in an embodiment of the present application.

[0015] Figure 2 It is a structural schematic diagram of a second connector in a low-frequency broadband filter provided in an embodiment of the present application.

[0016] Figure 3 It is a structural schematic diagram of a cover plate in a low-frequency broadband filter provided in an embodiment of the present application.

[0017] Figure 4 It is a structural schematic diagram of a metal shell in a low-frequency broadband filter provided in an embodiment of the present application.

[0018] Figure 5It is a structural schematic diagram of a flying rod in a low-frequency broadband filter provided in an embodiment of the present application.

[0019] Figure 6 It is a structural schematic diagram of an inductor in a low-frequency broadband filter provided in an embodiment of the present application.

[0020] Figure 7 It is a schematic diagram of the position distribution of resonator units in a low-frequency broadband filter provided in an embodiment of the present application.

[0021] Figure 8 It is a schematic diagram of a model simulation of a coupling disk (-35.7) between a first resonator and a fourth resonator and a coupling amount (24.4) of an inductor plate between a fourth resonator and a sixth resonator in a low-frequency broadband filter provided in an embodiment of the present application.

[0022] Fig. 9 It is a schematic diagram of a filter channel debugging curve in a low-frequency broadband filter provided in an embodiment of the present application.

[0023] In the figure: 1. metal shell; 2. cover plate; 3. tuning screw; 4. fixing screw; 5. first connector; 6. second connector; 7. resonator unit; 701. first resonator; 702. second resonator; 703. third resonator; 704. fourth resonator; 705. fifth resonator; 706. sixth resonator; 8. base; 9. flying rod; 901. coupling plate; 10. fixing piece; 11. inductor. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] The utility model provides a technical solution, a low-frequency broadband filter, see Figures 1 to 6, comprising a metal shell 1, a first connector 5 is installed on one side of the metal shell 1, a second connector 6 is installed on the other end of the metal shell 1, a base 8 is installed in the inner cavity of the metal shell 1, a cover plate 2 is arranged on the metal shell 1, a tuning screw 3 is installed on the cover plate 2, a fixing screw 4 is arranged on one side of the tuning screw 3, a resonator unit 7 is arranged on the base 8, and the resonator unit 7 includes a first resonator 701, a second resonator 702, a third resonator 703, a fourth resonator 704, and a fifth resonator 705 and the sixth resonator 706, a flying rod 9 is arranged between the second resonator 702 and the fourth resonator 704, a coupling disk 901 is installed at one end of the flying rod 9, an inductor 11 is arranged between the fourth resonator 704 and the sixth resonator 706, a fixing part 10 is arranged on the flying rod 9, and the flying rod 9 is installed with the inner cavity of the metal shell 1 through the fixing part 10, the tuning screw 3 passes through the cover plate 2 and the resonator unit 7 in sequence and is threadedly connected with the base 8, and the fixing screw 4 passes through the cover plate 2 and is connected with the fixing part 10.

[0026] See also Figure 3 , Figure 5 , Figure 6 , Figure 7 One end of the flying rod 9 is fixedly connected to the bottom side wall of the second resonator 702, the coupling disk 901 is arranged below the fourth resonator 704, one end of the flying rod 9 is bent upward and welded to the bottom side wall of the second resonator 702, one end of the flying rod 9 with the coupling disk 901 is arranged on the lower side of the fourth resonator 704, and a certain distance is left between the coupling disk 901 and the bottom side wall of the fourth resonator 704. Under the support of the flying rod 9, it is suspended in the air to form a low-end zero point, and the two ends of the inductance sheet 11 are fixedly connected to the inner cavity of the metal shell 1, and the two ends of the inductance sheet 11 are respectively arranged on the lower side of the fourth resonator 704 and the sixth resonator 706 to form a high-end zero point.

[0027] See also Figure 8 , Figure 8 This is a schematic diagram of the model simulation of the coupling disk 901 (-35.7) between the first resonator 701 and the fourth resonator 704 and the coupling amount (24.4) of the inductor 11 between the fourth resonator 704 and the sixth resonator 706. Fig. 9 , Fig. 9 Schematic diagram of the filter channel debugging curve.

[0028] The low-frequency broadband filter in the utility model is composed of a metal shell 1, a cover plate 2, a tuning screw 3, a fixing screw 4, a resonator unit 7, a flying rod 9 with a coupling plate 901 and an inductor 11;

[0029] The first connector 5 and the second connector 6 are respectively installed at both ends of the metal shell 1. A base 8 is installed in the chamber of the metal shell 1. The resonator unit 7 can be installed on the base 8 through the tuning screw 3 that penetrates the cover plate 2. The tuning screw 3 is threadedly connected with the base 8 after penetrating the resonator. The resonator unit 7 includes a first resonator 701, a second resonator 702, a third resonator 703, a fourth resonator 704, a fifth resonator 705 and a sixth resonator 706. The six resonators in the resonator unit 7 are as follows: Figure 7 The arrangement is as shown, and windows are opened between the resonators to form coupling;

[0030] A flying rod 9 is arranged between the second resonator 702 and the fourth resonator 704, and the flying rod 9 is fixedly installed with the inner cavity wall of the metal shell 1 through a fixing member 10. A coupling disk 901 is installed at one end of the flying rod 9, and one end of the flying rod 9 is bent upward and welded to the bottom side wall of the second resonator 702. One end of the flying rod 9 with the coupling disk 901 is arranged on the lower side of the fourth resonator 704, and a certain distance is left between the coupling disk 901 and the bottom side wall of the fourth resonator 704. Under the support of the flying rod 9, it is suspended in the air to form a low-end zero point. An inductor sheet 11 is arranged between the fourth resonator 704 and the sixth resonator 706, and the two ends of the inductor sheet 11 are respectively arranged on the lower side of the fourth resonator 704 and the sixth resonator 706 to form a high-end zero point. This technical solution has little effect on the resonant frequency, is easy to adjust to achieve the strength of the zero point, and achieves better out-of-band suppression effect for the low-bandwidth passband filter;

[0031] In the device, the low-frequency filter CT structure (such as between the first resonator 701 and the fourth resonator 704) can achieve the coupling enhancement effect by welding the coupling plate 901, and the corresponding passband bandwidth accounts for 20% or more, which is relatively simple and feasible to achieve using this solution.

[0032] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0033] In this document, unless otherwise clearly stipulated and limited, terms such as "installation", "setting", "connection", "fixation", and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in this utility model according to the specific circumstances.

[0034] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-frequency broadband filter, comprising a metal housing (1), characterized in that: A first connector (5) is installed on one side of the metal shell (1), and a second connector (6) is installed on the other end of the metal shell (1). A base (8) is installed in the inner cavity of the metal shell (1). A cover plate (2) is provided on the metal shell (1), and a tuning screw (3) is installed on the cover plate (2). A fixing screw (4) is provided on one side of the tuning screw (3). A resonator unit (7) is provided on the base (8). The resonator unit (7) includes a first resonator (701), a second resonator (702), a third resonator (703), a fourth resonator (704), a fifth resonator (705) and a sixth resonator (706). A flying rod (9) is provided between the second resonator (702) and the fourth resonator (704), and a coupling disk (901) is installed on one end of the flying rod (9). An inductor (11) is provided between the fourth resonator (704) and the sixth resonator (706).

2. A low-frequency broadband filter according to claim 1, characterized in that: A fixing piece (10) is provided on the flying rod (9), and the flying rod (9) is installed with the inner cavity of the metal shell (1) via the fixing piece (10).

3. A low-frequency broadband filter according to claim 1, characterized in that: One end of the flying rod (9) is fixedly connected to the bottom side wall of the second resonator (702), and the coupling plate (901) is arranged below the fourth resonator (704).

4. A low-frequency broadband filter according to claim 1, characterized in that: Two ends of the inductor (11) are fixedly connected to the inner cavity of the metal shell (1).

5. A low-frequency broadband filter according to claim 1, characterized in that: The tuning screw (3) sequentially passes through the cover plate (2) and the resonator unit (7) and is then threadedly connected to the base (8).

6. A low-frequency broadband filter according to claim 2, characterized in that: The fixing screw (4) passes through the cover plate (2) and is connected to the fixing member (10).

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