Wide-band adjustable filter and duplexer

Abstract

The utility model discloses a wide-frequency-band adjustable filter and a duplexer, and the wide-frequency-band adjustable filter comprises at least one resonant cavity, the at least one resonant cavity is internally provided with a resonant rod, and one side of the resonant rod is provided with a variable capacitance adjusting screw rod; wherein one side, close to the variable capacitance adjusting screw rod, of the resonance rod is provided with a first structure, one side, close to the resonance rod, of the variable capacitance adjusting screw rod is further provided with a second structure corresponding to the first structure, and the first structure and the second structure form a variable capacitor. The overlapping area of the first structure and the second structure is adjusted by rotating the variable capacitor screw, so that the capacitance value of the variable capacitor is adjusted, and then the resonant frequency of the wide-band adjustable filter is adjusted. Through the above structure, wide frequency band adjustability is realized.

Description

Technical Field

[0001] The present application relates to the technical field of communication devices, and in particular to a wide-band tunable filter and a duplexer. Background Art

[0002] As we all know, filters are one of the important components in communication systems. With the development of information technology, future communication systems are conducive to electronically adjustable or reconfigurable devices. Tunable filters can change their center frequency or bandwidth and are one of the key components of such devices. High durability, low insertion loss, good passband shape and reflection are the most required characteristics of tunable bandpass filters.

[0003] A notable feature of private network communication is that there are many frequency bands and many types of models, so maintenance requires more manpower and material costs. For example, the VHF (high frequency) band is from 136-174MHz, and there are countless filters according to the 2MHz bandwidth. If there is a way to reduce the types and reduce the filter types to 4, this solution will greatly reduce the number of encoding types and reduce material costs through normalization. Therefore, using a duplexer to debug products with multiple frequencies is of great significance to improving the platformization of duplexers and reducing management and manufacturing costs. Utility Model Content

[0004] The utility model aims to provide a wide-band adjustable filter and a duplexer, which are used to realize VHF wide-band adjustable.

[0005] In order to solve the above technical problems, the present application provides a wide-band tunable filter and a duplexer, comprising: at least one resonant cavity, at least one of the resonant cavities is provided with a resonant rod, and a variable capacitance adjustment screw is provided on one side of the resonant rod; wherein, a first structure is provided on a side of the resonant rod close to the variable capacitance adjustment screw, and a second structure corresponding to the first structure is also provided on a side of the variable capacitance adjustment screw close to the resonant rod, the first structure and the second structure form a variable capacitor, and the overlapping area of ​​the first structure and the second structure is adjusted by rotating the variable capacitance adjustment screw to adjust the capacitance value of the variable capacitor, thereby adjusting the resonant frequency of the wide-band tunable filter.

[0006] Preferably, the main body of the variable capacitance adjustment screw is arranged parallel to the main body of the resonance rod; the first structure is arranged perpendicular to the main body of the resonance rod and toward the direction of the variable capacitance adjustment screw; the second structure is arranged vertically on one side of the variable capacitance adjustment screw.

[0007] Preferably, the second structure can rotate 180 degrees or 360 degrees along the main body of the variable capacitance adjusting screw.

[0008] Preferably, the first structure includes at least one first metal plate that is parallel to each other and spaced apart, and the second structure includes at least one second metal plate that is parallel to each other and spaced apart, wherein the second metal plate is inserted into the gap between adjacent first metal plates and spaced apart from each first metal plate to form the variable capacitor with each first metal plate.

[0009] Preferably, one end of the variable capacitance adjusting screw protrudes from the resonant cavity to facilitate the rotation of the variable capacitance adjusting screw, thereby causing the second structure to rotate in a direction away from or close to the first structure.

[0010] Preferably, a cavity is further provided at the axial core position of the resonance rod, and the wide-band tunable filter further comprises a tuning screw arranged in the cavity of the resonance rod, and the tuning screw is spaced apart from the side wall of the resonance rod to form a tuning capacitor.

[0011] Preferably, the diameter of the resonant rod at a position corresponding to the cavity is larger than the diameter of the main body of the resonant rod.

[0012] Preferably, the wide-band tunable filter further comprises a cover plate arranged close to the tuning screw, the cover plate is hollowed out at the center corresponding to the tuning screw, and the tuning screw passes through the hollow part of the cover plate and extends into the cavity of the resonance rod.

[0013] Preferably, at least two of the resonant cavities are arranged in a line and are interconnected.

[0014] To solve the above technical problems, the present application also provides a duplexer, including a transmitting channel and a receiving channel, wherein both the transmitting channel and the receiving channel are filtered by the wide-band tunable filter described in any of the above embodiments to achieve wide-band tunability.

[0015] The beneficial effect of the present application is that a first structure is formed on the resonance rod, and a second structure is formed on the variable capacitance adjustment screw, so that the first structure and the second structure are overlapped to form a variable capacitance. The overlapping area of ​​the second structure and the first structure is adjusted by rotating the variable capacitance adjustment screw, thereby adjusting the capacitance value between the resonance rod and the variable capacitance adjustment screw, and then adjusting the resonant frequency of the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 This is a schematic cross-sectional structure diagram of the first embodiment of the wide-band tunable filter of the present application;

[0018] Figure 2 This is a schematic cross-sectional structure diagram of a second embodiment of the wide-band tunable filter of the present application;

[0019] Figure 3 This is a schematic diagram of the top view of the structure of the second embodiment of the wide-band tunable filter of the present application;

[0020] Figure 4 This is a schematic cross-sectional structural diagram of an embodiment of a duplexer of the present application;

[0021] Figure 5 This is a schematic diagram of a top view of the structure of an embodiment of a duplexer of the present application;

[0022] Figure 6 This is a simulation comparison diagram of a duplexer of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. 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 this field without creative work are within the scope of protection of this application.

[0024] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "said", and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless otherwise clearly indicated above, and "multiple" generally includes at least two, but does not exclude the inclusion of at least one.

[0025] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0026] It should be understood that the terms "include", "comprises" or any other variations used herein are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "includes..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0027] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The presence of the phrase at each location in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] The present application is now further described with reference to the accompanying drawings and specific embodiments.

[0030] This application provides a wide-band tunable filter, see Figures 1 to 3 , Figure 1 This is a schematic cross-sectional view of the first embodiment of the wide-band tunable filter of the present application. Figures 1 to 3 Specifically, it is a schematic diagram of a single cavity structure of a wide-band tunable filter. Figure 1 As shown, the wide-band tunable filter comprises at least: a resonant cavity 1 , a resonant rod 2 is disposed in at least one resonant cavity 1 , and a variable capacitance adjusting screw 3 is disposed on one side of the resonant rod 2 .

[0031] A first structure 21 is provided on one side of the resonance rod 2 close to the variable capacitance adjustment screw 3. A second structure 31 corresponding to the first structure 21 is also provided on one side of the variable capacitance adjustment screw 3 close to the resonance rod 2. The first structure 21 and the second structure 31 form a variable capacitor C, and the overlapping area of ​​the first structure 21 and the second structure 31 is adjusted by rotating the variable capacitance adjustment screw 3, thereby adjusting the capacitance value of the variable capacitor C, and further adjusting the resonant frequency of the wideband adjustable filter.

[0032] Specifically, the body of the variable capacitance adjustment screw 3 is arranged parallel to the body of the resonance rod 2. The first structure 21 is arranged perpendicular to the body of the resonance rod 2 and toward the variable capacitance adjustment screw 3, and the second structure 31 is arranged perpendicularly to one side of the variable capacitance adjustment screw 3, so that the first structure 21 and the second structure 31 can be arranged parallel to each other.

[0033] In a specific embodiment, the second structure 31 rotates 180 degrees or 360 degrees along a main axis perpendicular to the variable capacitance adjusting screw 3 , which is not limited here.

[0034] For more details, please refer to Figure 2 , Figure 2 This is a schematic diagram of the cross-sectional structure of the second embodiment of the wide-band tunable filter of the present application. Figure 2 As shown, when the variable capacitance adjusting screw 3 rotates 180 degrees, the second structure 31 rotates along the main body of the variable capacitance adjusting screw to be disposed away from the first structure 21 , that is, is located at the farthest end of the first structure 21 . Figure 1 In the figure, the second structure 31 is the result of a rotation of 0 degrees or 360 degrees, and the second structure 31 is located closest to the first structure 21.

[0035] In this specific embodiment, the first structure 21 includes a plurality of first metal plates (not numbered, which can be understood as the same number as the first structure 21) that are parallel to each other and spaced apart, and the second structure 31 includes a plurality of second metal plates (not numbered) that are parallel to each other and spaced apart. The second metal plate is inserted into the gap between two adjacent first metal plates so that each first metal plate is spaced apart from two adjacent second metal plates, so that the first metal plate and the second metal plate are arranged crosswise with each other. Among them, each second metal plate forms a variable capacitor with its adjacent first metal plate, thereby forming a plurality of variable capacitors. Among them, each first metal plate and each second metal plate are also parallel and spaced apart from each other. In the first specific embodiment, the number of the second metal plate and the first metal plate can be the same, or it can be less than the number of a first metal plate, that is, the number of the second metal plate and the first metal plate does not differ by more than 1.

[0036] The shapes of the first metal plate and the second metal plate may be the same or different, which is not limited here.

[0037] For further information, please refer to Figure 3 , Figure 3 This is a schematic diagram of the top view of the second embodiment of the wide-band tunable filter of the present application. Figure 3 As shown, the first metal plate of the first structure 21 is a square plate, and one side of the second metal plate of the second structure 31 can be an arc-shaped plate. In other embodiments, it can also be other shapes, which are not limited here.

[0038] In a specific embodiment, one end of the variable capacitance adjusting screw 3 protrudes from the shell surface of the resonant cavity 1, so as to facilitate the rotation of the variable capacitance adjusting screw 3, thereby driving the second structure 31 to rotate in a direction away from or close to the first structure 21. Figure 1-2 The rotation result is shown as follows, and it can be rotated within at least 0-180 degrees. It can be rotated manually or mechanically, which is not limited here. In other embodiments, a rotating structure protruding from the cavity of the resonant cavity 1 can also be set on the variable capacitance adjustment screw 3, which is not limited here.

[0039] Furthermore, the wideband tunable filter also includes a tuning screw 4. A cavity is also provided at the axis core position of the resonance rod 2, and the tuning screw 4 is provided in the cavity. The tuning screw 4 is spaced apart from the inner wall of the resonance rod 2, and the tuning screw 4 and the inner wall of the resonance rod 2 form a tuning capacitor C1. In this embodiment, the tuning capacitor C1 can be fixed.

[0040] It should be noted that, in this embodiment, the main body of the resonance rod 2, the main body of the variable capacitance adjustment screw 3 and the tuning screw 4 are all cylindrical rod-shaped structures.

[0041] In this specific embodiment, the cavity is disposed at one end of the resonance rod 2. In other embodiments, the cavity may also be disposed in the middle of the resonance rod 2, which is not limited here. Preferably, the cavity is disposed at one end of the resonance rod 2 on which the first structure 21 is disposed, so as to correspond to the first structure 21, and the tuning screw 4 can be fixed on the cavity wall of the resonance cavity 1, so as to fix the distance between the tuning screw 4 and the inner wall of the resonance rod 2, thereby forming a fixed tuning capacitor. In other embodiments, it may also be fixed in other ways, which are not limited here.

[0042] Preferably, the inner wall of the cavity of the resonance rod 2 is cylindrical, the tuning screw 4 is a cylinder, and the axis of the tuning screw 4 coincides with the axis of the main body of the resonance rod 2, so that the spacing between the tuning screw 4 and the inner wall of the resonance rod 2 is the same in all directions. In other embodiments, other shapes and structures may also be used, which are not limited here. It can be understood that the cavity diameter of the resonance rod 2 is larger than the diameter of the tuning screw 4.

[0043] In a preferred embodiment, the diameter of the resonance rod 2 at the corresponding cavity position is greater than the diameter of the main body of the resonance rod 2. The first structure 21 is arranged at the corresponding position of the cavity, so that the capacitance between the resonance rod 2 and the variable capacitance adjustment screw 3 is mainly formed by the first structure 21 and the second structure 31, weakening the capacitance between the main body of the resonance rod 2 and the main body of the variable capacitance adjustment screw 3. In other embodiments, the entire core of the resonance rod 2 can also be arranged as a cavity, and the diameter of the main body of the resonance rod 2 is the same, which is not limited here.

[0044] In a preferred embodiment, the wideband tunable filter further includes a cover plate 5 disposed near the tuning screw 4. The cover plate 5 is hollowed out at the center of the corresponding tuning screw 4, so that the tuning screw 4 extends through the hollow of the cover plate 5 into the cavity of the resonance rod 2. The axis of the cover plate 5 coincides with the axis of the tuning screw 4, and the cover plate 5 can move along the axis of the tuning screw 4, thereby adjusting the capacitance value of the tuning capacitor C1, which is not limited here.

[0045] Specifically, the cover plate 5 is disposed at one end of the resonance rod 2 where the cavity is disposed, so as to correspond to the tuning screw 4 .

[0046] It can be understood that the shell of the resonance cavity 1 includes an upper cover and a lower cover, the resonance rod 2 is fixed to the lower cover, and the tuning screw 4 can be fixed to the upper cover, and the cover plate 5 is arranged on the upper cover, adjacent to the tuning screw 4. Among them, the cover plate 5 can be a disc, the axis core of the disc is hollow, and the tuning screw 4 extends into the cavity of the resonance rod 2 through the hollow part of the cover plate 5. Preferably, the diameter of the hollow area of ​​the cover plate 5 can be the same as the diameter of the cavity of the resonance cavity 1, or it can be different, which is not limited here. Further, the variable capacitance adjustment screw 3 can be fixed to the upper cover. Among them, the upper cover and the lower cover can be interchanged in relative position, which is not limited here. The resonance cavity 1, the tuning screw 4 and the variable capacitance adjustment screw 3 can all be fixed to the shell of the resonance cavity 1 by screws, which is not limited here.

[0047] Furthermore, the wide-band tunable filter may also include a plurality of resonant cavities 1 , the plurality of resonant cavities 1 are arranged in a line, and the plurality of resonant cavities 1 are interconnected.

[0048] This application also provides a duplexer. Figure 4-5 , Figure 4 It is a schematic cross-sectional structure diagram of an embodiment of a duplexer of the present application. Figure 5 FIG. 1 is a schematic diagram of a top view of a duplexer according to an embodiment of the present invention. Figure 4 As shown, it includes a transmitting channel 101 and a receiving channel 102. Both the transmitting channel 101 and the receiving channel 102 are filtered by a wide-band adjustable filter, so that the frequency band can be adjusted within 10 MHz.

[0049] Among them, multiple resonant cavities 1 are arranged in a line, and the transmitting channel 101 and the receiving channel 102 are arranged on opposite sides of the entire resonant cavity 1. Specifically, the transmitting channel 101 is connected to the resonant rod 2 in one of the resonant cavities 1, and the receiving channel 102 is connected to the resonant rod 2 in the farthest resonant cavity 1 of the resonant cavity 1.

[0050] The duplexer includes a plurality of resonant cavities 1, and the variable capacitance adjusting screws 3 in the plurality of resonant cavities 1 can be adjusted separately, that is, they can be adjusted asynchronously. In this embodiment, the number of resonant cavities 1 is not limited. The length of the tuning screw 4 in the middle resonant cavity 1 is usually less than the length of the tuning screw 4 in the resonant cavity 1 at the edge connected to the transmitting channel 101 and the receiving channel 102.

[0051] It should be noted that the resonant frequency of the filter is related to the capacitance value. For details, refer to the formula Among them, the capacitor Among them, S is the effective area between the two plates of the capacitor, d is the distance between the two plates of the capacitor, and K is a constant. Therefore, when S and d change, the capacitance C will also change, and thus the resonant frequency Fr will also change.

[0052] Please refer to the following for further details Figure 6 , Figure 6 This is a simulation comparison diagram of a duplexer of this application. Figure 6 As shown, curve 100 is the frequency band before retuning, and curve 200 is the frequency band after retuning through the above-mentioned filter or duplexer. Among them, the frequency band before retuning is 142-145MHz, and the frequency band after retuning is 132-135MHz, with a frequency shift of 10MHz. Therefore, the 10MHz frequency band before and after retuning can be adjusted through the filter or duplexer, so that it can receive signals in a wider frequency band through adjustment. In other embodiments, the frequency band before retuning is 132-135MHz, and the frequency band after retuning is 142-145MHz, achieving a right frequency modulation of 10MHz, which is not limited here.

[0053] The beneficial effect of the present application is: by forming a first structure on the resonant rod and a second structure on the variable capacitance adjustment screw, the first structure and the second structure are overlapped to form a variable capacitance. The overlapping area of ​​the second structure and the first structure is adjusted by rotating the variable capacitance adjustment screw, thereby adjusting the capacitance value between the resonant rod and the variable capacitance adjustment screw, and then adjusting the resonant frequency of the filter. In addition, the second structure in the present application can achieve 180 degrees of rotation angle adjustment, so that a wider frequency band (±10MHz frequency) can be adjusted.

[0054] The above description is only an implementation method of the present application, and does not limit the patent protection scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A wide-band tunable filter, characterized in that: The wide-band tunable filter comprises: at least one resonant cavity, at least one resonant cavity is provided with a resonant rod, and a variable capacitance adjustment screw is provided on one side of the resonant rod; wherein, a first structure is provided on a side of the resonant rod close to the variable capacitance adjustment screw, and a second structure corresponding to the first structure is also provided on a side of the variable capacitance adjustment screw close to the resonant rod, the first structure and the second structure form a variable capacitor, and the overlapping area of ​​the first structure and the second structure is adjusted by rotating the variable capacitance adjustment screw to adjust the capacitance value of the variable capacitor, thereby adjusting the resonant frequency of the wide-band tunable filter.

2. The wide-band tunable filter according to claim 1, characterized in that: The main body of the variable capacitance adjustment screw is arranged parallel to the main body of the resonance rod; the first structure is arranged perpendicular to the main body of the resonance rod and toward the direction of the variable capacitance adjustment screw; the second structure is arranged vertically on one side of the variable capacitance adjustment screw.

3. The wide-band tunable filter according to claim 2, characterized in that: The second structure can rotate 180 degrees or 360 degrees along the body of the variable capacitance adjustment screw.

4. The wide-band tunable filter according to claim 3, characterized in that: The first structure includes at least one first metal plate that is parallel to each other and spaced apart, and the second structure includes at least one second metal plate that is parallel to each other and spaced apart, wherein the second metal plate is inserted into the gap between adjacent first metal plates and spaced apart from each first metal plate to form the variable capacitor with each first metal plate.

5. The wide-band tunable filter according to claim 3, characterized in that: One end of the variable capacitance adjusting screw protrudes from the resonant cavity to facilitate the rotation of the variable capacitance adjusting screw, thereby causing the second structure to rotate in a direction away from or close to the first structure.

6. The wide-band tunable filter according to claim 1, characterized in that: A cavity is also arranged at the axis core position of the resonance rod, and the wide-band tunable filter also includes a tuning screw arranged in the cavity of the resonance rod, and the tuning screw is spaced apart from the side wall of the resonance rod to form a tuning capacitor.

7. The wide-band tunable filter according to claim 6, characterized in that: The diameter of the resonant rod at a position corresponding to the cavity is greater than the diameter of the main body of the resonant rod.

8. The wide-band tunable filter according to claim 6, characterized in that: The wide-band tunable filter also includes a cover plate arranged near the tuning screw, the cover plate is hollowed out at the center corresponding to the tuning screw, and the tuning screw passes through the hollow part of the cover plate and extends into the cavity of the resonance rod.

9. The wide-band tunable filter according to claim 1, characterized in that: At least two of the resonant cavities are arranged in a line and are interconnected.

10. A duplexer, characterized in that: It comprises a transmitting channel and a receiving channel, and both the transmitting channel and the receiving channel are filtered by the wide-band adjustable filter according to any one of claims 1 to 9 to achieve wide-band adjustableness.

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