A band-stop filter

Abstract

The present invention relates to the field of filter technology, and specifically to a band-stop filter, wherein the filter of the present application comprises a filter body and a cavity arranged in the filter body, at least two connectors connected to external signals are arranged on one side or both sides of the filter body, the cavity is connected to a cover plate through a connecting rod, and at least one resonator and a coupler are arranged in the cavity; the resonators are all provided with different resonant frequencies; the coupler is connected to the resonator, and the coupling amount of the coupler is adjustable; through the above design, the coupling amount of at least two couplers can be adjusted, thereby realizing a low-frequency filter structure with at least two stopbands and multiple passbands, effectively solving the needs of multiple passbands and multiple stopbands; at the same time, the present application meets the needs of different transition bands and different stopband bandwidths through an adjustable coupler structure.

Description

Technical Field

[0001] The present invention relates to the technical field of filters, and in particular to a band-stop filter. Background Art

[0002] With the rapid development of wireless communication technology, especially after entering the 5G era, spectrum resources in radio communications have become increasingly tight, and efficient use of spectrum has become particularly important. As an indispensable component in wireless communication systems, the performance of filters has a direct impact on the overall frequency band selection, interference suppression and signal quality of the system. Especially in high-frequency communications, cavity filters are widely used due to their excellent quality factor (Q value), low insertion loss and good temperature stability. This type of filter can not only maintain excellent performance in complex electromagnetic environments, but also achieve multi-band selectivity through structural optimization and design innovation, thereby meeting the needs of high speed, large capacity and multi-band in the 5G era.

[0003] Although current filter technology is widely used, especially cavity filters, they still face many challenges in design and function. In traditional designs, the selectivity of passband and stopband is usually achieved through a fixed structure, which makes it particularly difficult to flexibly adjust the frequency. In addition, multi-band communication environments place higher requirements on the broadband suppression characteristics and penetration performance of filters. Existing technologies are difficult to achieve multi-passband and dual-band stop characteristics at the same time, especially in low frequency bands. Existing filters are usually subject to their inherent frequency limitations, respond slowly to new spectrum adjustment requirements, and lack adjustable capabilities, which makes them inadequate in adapting to rapidly changing radio frequency planning.

[0004] Based on this, a band-stop filter is urgently needed to solve the defects of the filter structure in the prior art. Summary of the invention

[0005] One of the purposes of the present invention is to provide a band-stop filter based on the deficiencies of the prior art to solve the problems of poor adjustability, inflexible frequency band design, and insufficient adaptability in traditional filters.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A band-stop filter, comprising a filter body and a cavity arranged in the filter body, characterized in that at least two connectors connected to external signals are arranged on one side or both sides of the filter body, the cavity is connected to a cover plate through a screw, and at least one resonator and a coupler are arranged in the cavity;

[0008] Furthermore, the resonators are all provided with different resonant frequencies;

[0009] Furthermore, a coupler is connected to the resonator, and a coupling amount of the coupler is adjustable.

[0010] Through the above technical solution, this application achieves the following technical effects:

[0011] The band-stop filter of the present invention realizes precise control of the resonant frequency by setting a coupler with adjustable coupling amount, thereby providing flexible frequency adjustment capability. Users can adjust the passband and stopband of the filter according to actual needs to adapt to different wireless communication spectrum planning.

[0012] As a further improvement to the band-stop filter of the present invention, the resonator includes a first resonance unit and a second resonance unit, both of which are connected to the cavity through a coupler; and multiple pairs of the first resonance unit and the second resonance unit are symmetrically arranged.

[0013] As a further improvement to the band-stop filter of the present invention, the resonator is provided with a side wall hole, and the side wall hole is connected to the coupler through a connecting rod.

[0014] As a further improvement to the band-stop filter of the present invention, the coupler comprises a coupling disk and a coupling sheet connected to the cavity;

[0015] Furthermore, the coupling piece is provided with a bending body and a connecting body; the bending body is a U-shaped structure, one end of which is connected to the cavity, and the other end is connected to the connecting body.

[0016] As a further improvement to the band-stop filter of the present invention, a through hole is provided through the coupling disk, the through hole is provided through the connecting rod, and one end of the connecting rod away from the side wall hole is connected to the connector.

[0017] As a further improvement to the band-stop filter of the present invention, the distance between the coupling plate and the coupling disk is 1.5 mm-2.5 mm.

[0018] As a further improvement to the band-stop filter of the present invention, the cover plate is provided with an opening at a position corresponding to the coupling plate, and the opening is used to receive an external paddle; the external paddle is used to adjust the distance between the coupling plate and the coupling disk.

[0019] As a further improvement to the band-stop filter of the present invention, the connector includes a first connector and a second connector, the first connector is used to input an external signal, and the second connector is used to output a signal processed by the filter.

[0020] As a further improvement to the band-stop filter of the present invention, the frequency band of the input signal of the first connector is 50 MHz-3000 MHz, and the frequency band of the output signal of the second connector is 700 MHz-900 MHz.

[0021] As a further improvement to the band-stop filter of the present invention, the coupling plate is fixed in the cavity through a metal medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the cavity structure of the present invention;

[0024] Figure 3 It is an exploded view of the structure of the present invention;

[0025] Figure 4 It is the normal temperature technical index curve of the product and material of the present invention;

[0026] Figure 5 It is the low temperature technical index curve of the product and material of the present invention;

[0027] Figure 6 It is the high temperature technical index curve of the products and materials of the present invention.

[0028] In the figure:

[0029] DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] 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", "comprises" or any other variations 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 includes elements inherent to such process, method, article or device.

[0032] In the field of communication systems, band-stop filters are widely used to reduce interference noise. In view of the complexity and variability of the communication environment, signals are easily interfered with by various noises during transmission, thus affecting the quality of communication. Those skilled in the art have found that the introduction of band-stop filters in communication systems can effectively filter out interference noise of specific frequencies, thereby improving the signal-to-noise ratio of signals and the reliability of communication. For example, in radio communications, band-stop filters can be used to eliminate harmonic interference generated by power supplies or other devices to ensure clear transmission of communication signals. The design of band-stop filters is highly flexible, and parameters such as passband, blocking, bandwidth, and suppression attenuation can be adjusted according to different application requirements to meet specific filtering requirements.

[0033] However, the technical personnel of this application have found that the current production cost of band-stop filters is high, the reproducibility of mass production is low, the filter parameter indicators are usually difficult to accurately quantify, and the difference fluctuation range is larger than that of conventional bandpass filters. During the production process, the product is highly sensitive, difficult to debug, and difficult to restore the original indicators once disassembled. There are bottlenecks in the production threshold, and the reversibility of maintenance is not high. In view of the many shortcomings of existing solutions, this application aims to solve the above problems and achieve the goal of low-cost, large-scale production, which successfully solves the noise and interference problems in the communications industry.

[0034] Specifically, the design parameters of the stopband filter include parameters such as passband frequency, stopband frequency, passband insertion loss and stopband suppression. Since the present application only improves the low-frequency filter, the technical solution of the present application considers processing a signal frequency range of 700-900MHz. Taking three passband frequencies of 764MHz-797MHz / 814MHz-824MHz / 859MHz-869MHz and two stopband frequencies of 806MHz-809 MHz / 851MHz-854MHz as examples, the present invention solves the requirements of multiple passbands and multiple stopbands through a combination of band-stop filters, and solves the requirements of different transition bands and different stopband bandwidths through an adjustable coupling plate structure. In order to further reflect the working principle and specific structure of the technical solution of the present application, the present invention is further described in detail below in combination with specific embodiments, but the embodiments of the present invention are not limited to this.

[0035] Example 1

[0036] like Figure 1-3As shown, in order to solve the problems of poor adjustability, inflexible frequency band design, and insufficient adaptability in existing traditional filters, the present application specifically comprises a band-stop filter comprising a filter body 1 and a cavity 2 arranged on the filter body 1, at least two connectors 11 connected to external signals are arranged on one side or both sides of the filter body 1, the cavity 2 is connected to the cover plate 3 by a screw 12, and at least one resonator 21 and a coupler 22 are arranged in the cavity 2; wherein the resonators 21 are all provided with different resonant frequencies; the coupler 22 is connected to the resonator 21, and the coupling amount of the coupler 22 is adjustable.

[0037] Specifically, in the filter design of the present application, the adjustment of each resonator 21 can support specific passbands and stopbands. The specific implementation principle is as follows:

[0038] First, each resonator 21 has a specific resonant frequency, near which it allows signals to pass. In the specific implementation process, the resonant frequency can be set by designing the physical structure of the resonator 21 (such as length, width, material, etc.). Furthermore, in the present application, multiple resonators 21 can be combined in series or in parallel to form an overall passband response. By adjusting the coupling strength between these resonators 21, the width and shape of the passband can be changed to meet specific frequency range requirements. Secondly, in the specific implementation process, the present application can adjust the width of the passband by controlling the Q factor of the resonator 21. (Wherein, high Q factor resonators 21 form narrower passbands, while low Q factor resonators 21 form wider passbands.)

[0039] Secondly, if the coupling amount of the coupler 22 between the connection of a single resonator 21 and the cavity 2 is relatively low or the coupling amount between multiple resonators 21 is designed to be very low, then a damping effect will occur at these locations, creating a stop band. The design and adjustment of the coupler 22 is an important factor affecting the blocking characteristics. By adjusting the coupler 22, the blocking position and depth can be effectively controlled.

[0040] Furthermore, at the same time, in the present application, several individual resonators 21 in the array of resonators 21 may be designed to significantly increase the loss in a certain frequency band to form a retardation. This can be achieved by adding or removing certain components or changing the structure of the resonator 21. For example, by using specific materials or independent mechanical adjustment structures (such as the adjustable connecting rod 4) to change the electromagnetic characteristics and load conditions of the resonator 21, the retardation effect can be enhanced.

[0041] Furthermore, the resonator 21 of the present application includes a first resonant unit 211 and a second resonant unit 212, and the first resonant unit 211 and the second resonant unit 212 are both connected to the cavity 2 through a coupler 22; wherein the first resonant unit 211 and the second resonant unit 212 are symmetrically arranged in multiple pairs. The multiple pairs of the first resonant unit 211 and the second resonant unit 212 can achieve the same frequency band bandpass, and can also achieve the bandpass of different frequency bands.

[0042] In the embodiment of the present application, the coupler 22 of the resonator 21 is an adjustable coupling plate 222 structure, which allows the user to adjust the coupling amount according to actual needs, thereby realizing flexible control of different transition bands and stop band bandwidths. This design not only improves the adaptability of the filter, but also simplifies the production process and reduces costs.

[0043] In order to further improve the performance of the filter, the present application also proposes a cavity 2 design, which is connected to the cover plate 3 through a connecting rod 4, so that the resonator 21 and the coupler 22 inside the cavity 2 can be positioned and fixed. This design ensures the stability and reliability of the filter during the production process, and is also convenient for later maintenance and adjustment.

[0044] In summary, the band-stop filter proposed in this application achieves precise control of the passband and stopband through the innovative design of the resonator 21 and the coupler 22, while reducing production costs and improving the reproducibility of mass production. The filter is not only suitable for the field of radio communications, but can also be widely used in other communication systems that need to filter out specific frequency interference, providing an effective technical means for improving communication quality.

[0045] Example 2

[0046] like Figure 1-3 As shown, the difference from Example 1 is that: in order to further illustrate the principle of coupling of the filter resonator 21 of the present application through the coupler 22, further, the resonator 21 is provided with a side wall hole 213, and the side wall hole 213 is connected to the coupler 22 through the connecting rod 4. Through the design of the side wall hole 213, the coupling between the resonator 21 and the coupler 22 can be achieved, so as to adjust the passband and stopband characteristics of the filter. The design of the side wall hole 213 allows the user to adjust the coupling amount by changing the length or position of the connecting rod 4, thereby affecting the resonant frequency and coupling strength of the resonator 21.

[0047] Specifically, the connection between the side wall hole 213 of the resonator 21 and the coupler 22 adopts an adjustable structure, for example, by using a threaded connection or a sliding device, the user can fine-tune the resonant frequency of the resonator 21 according to actual needs. This design not only improves the flexibility of the filter, but also simplifies the debugging steps in the production process and reduces the requirements on the skills of the operator.

[0048] Furthermore, this embodiment proposes an improved design of the cavity 2, which enables the resonator 21 and the coupler 22 inside the cavity 2 to be more accurately positioned and fixed by setting a plurality of adjustment holes on the surface of the cavity 2. At the same time, the design of the adjustment hole allows the user to adjust the resonant frequency by rotating the connecting rod 4 on the adjustment hole (also used to achieve the connection between the cover plate 3 of this application and the cavity 2). This design not only improves the performance stability of the filter, further ensures that the product cover plate 3 does not need to be removed during the tuning process, but also facilitates subsequent maintenance and adjustment.

[0049] Furthermore, the coupler 22 includes a coupling disk 221 and a coupling plate 222 connected to the cavity 2; the coupling plate 222 is provided with a bending body 2222 and a connecting body 2221; the bending body 2222 is a U-shaped structure, one end of which is connected to the cavity 2, and the other end is connected to the connecting body 2221. In the specific implementation process, the coupling amount of the coupler 22 can be adjusted by changing the bending angle of the bending body 2222. This design allows the user to fine-tune the passband and stopband characteristics of the filter through a simple rotation operation without changing the physical structure of the resonator 21, thereby improving the convenience of operation and the adaptability of the filter.

[0050] Specifically, the present application adopts a modular design concept, and designs the filter body 1 into multiple modules, each module including a resonator 21 and a coupler 22. This modular design is not only convenient for assembly and debugging during the production process, but also allows for quick replacement of damaged modules during later maintenance, greatly reducing maintenance costs and time.

[0051] Furthermore, the coupling disc 221 is provided with a through hole 2211, and the through hole 2211 is provided through the connecting rod 4, and one end of the connecting rod 4 away from the side wall hole 213 is connected to the connecting body 2221. Among them, the side of the connecting rod 4 used to connect the connecting body 2221 can be threaded or welded. Through the design of the connecting rod 4, the coupling disc 221 located in the connecting rod 4 can be moved, thereby adjusting the distance between the coupling disc 221 and the connecting body 2221, and further adjusting the coupling amount of the coupler 22. Among them, the distance between the coupling plate 222 and the coupling disc 221 is 1.5mm-2.5mm (the distance range can be adjusted according to the specific situation), and in the specific implementation process, it can be any one or more of 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm and 2.5mm. Specifically, the relationship between the coupling amount and the distance between the coupling plate 222 and the coupling plate 221 is: when the distance between the coupling plate 222 and the coupling plate 221 increases, the coupling amount will decrease accordingly, and vice versa. This is because the coupling amount is related to the electromagnetic field coupling strength between the two resonators 21. The closer the distance, the greater the coupling strength, which leads to an increase in the coupling amount.

[0052] Specifically, the cover plate 3 is provided with an opening 31 at a position corresponding to the coupling plate 222, and the opening 31 is used to receive an external paddle; the external paddle is used to adjust the distance between the coupling plate 222 and the coupling disk 221. In the specific implementation process, the distance between the coupling plate 222 and the coupling disk 221 can be adjusted by rotating the external paddle, thereby achieving fine-tuning of the passband and stopband characteristics of the filter. This design allows the user to accurately control the performance of the filter by rotating the external paddle without opening the filter cover plate 3, further improving the convenience of operation and the adaptability of the filter.

[0053] In summary, the present application not only improves the performance stability of the filter, but also enhances the convenience of operation and the simplicity of maintenance. Other aspects that are the same as those in Embodiment 1 will not be described in detail in this embodiment.

[0054] Example 3

[0055] like Figure 1-3As shown, the difference from Example 1 is that: in order to further improve the processing of data by the filter device of the present application, the connector 11 includes a first connector 111 and a second connector 112, the first connector 111 is used to input external signals, and the second connector 112 is used to output signals processed by the filter. Further, the frequency band of the input signal of the first connector 111 is 50MHz-3000MHz, and the frequency band of the output signal of the second connector 112 is 700MHz-900MHz. Among them, in the specific implementation process, the design parameters of the stop filter include parameters such as passband frequency, stopband frequency, passband insertion loss and stopband suppression, and the preferred frequency range of the technical solution of this application is 700MHz-900MMHz. Within this working frequency band, this application can use three passband frequencies of 764MHz-797MHz / 814MHz-824MHz / 859MHz-869MHz and two stopband frequencies of 806MHz-809 MHz / 851MHz-854MHz to effectively solve the needs of multiple passbands and multiple stopbands and solve the needs of different transition bands and different stopband bandwidths through the adjustable coupling plate 222 structure. It should be noted that the passband range of this application is any passband interval and multiple passband intervals and stopband intervals in 700MHz-900MMHz.

[0056] Furthermore, the coupling plate 222 of the present application is fixed in the cavity 2 through the metal medium 23. Due to the design of the metal medium 23, it can ensure that there is a good electrical connection between the coupling plate 222 and the cavity 2, and at the same time provide sufficient mechanical strength to support the coupling plate 222. The use of the metal medium 23 not only improves the stability and reliability of the filter, but also can effectively reduce signal loss and electromagnetic interference in a high-frequency working environment.

[0057] In summary, the band-stop filter proposed in this embodiment realizes the control of the passband and the stopband through the design of the side wall hole 213 of the resonator 21, while reducing the production cost and improving the reproducibility of mass production. The filter is not only suitable for the field of radio communication, but also can be widely used in other communication systems that need to filter out specific frequency interference, providing an effective technical means for improving communication quality.

[0058] Further, in order to reflect the technical effect of the low-frequency adjustable dual-band-stop filter prepared by the present application, the present application will test the debugging curve of the filter under the following conditions:

[0059] Adjustable range: 700MHz-900MHz;

[0060] Passband frequency: 764MHz-797MHz / 814MHz-824MHz / 859MHz-869MHz;

[0061] Stopband frequency: 806MHz-809MHz / 851MHz-854MHz;

[0062] Index requirements: transition band: 5MHz, stop band bandwidth: 3MHz, pass band insertion loss: 1.5dB,

[0063] Stopband suppression: 40dB.

[0064] However, usually the product is debugged at room temperature to ensure that all indicators are met. During the normal temperature debugging process, a certain indicator margin is usually reserved according to the product simulation situation to ensure that the product can be used in different environments; after the normal temperature debugging is completed, the product will be aged at high temperature to release the structural stress. After returning to normal temperature, the indicators need to be retested; specifically, the product of this application has undergone reliability verification of low temperature debugging, normal temperature debugging and high temperature debugging (see Figure 4 The normal temperature technical index curve of the product and material of the present invention shown, Figure 5 The low temperature technical index curves of the products and materials of the present invention are shown and Figure 6 As shown in the high-temperature technical index curve of the product and material of the present invention, the product performance index can be measured at two different extreme temperatures (low temperature state and high temperature state) after 1 / 2. It can be judged by the high and low temperature test curve that the product can work normally and meet the requirements in all covered temperature ranges.

[0065] Other details that are the same as those in Example 1 are not described in detail in this example.

[0066] 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 band-stop filter, comprising a filter body (1) and a cavity (2) arranged in the filter body (1), characterized in that: At least two connectors (11) connected to external signals are arranged on one side or both sides of the filter body (1); the cavity (2) is connected to the cover plate (3) via a screw rod (12); and a plurality of resonators (21) and a plurality of couplers (22) are arranged in the cavity (2); The coupler (22) is connected to the resonator (21), and the coupling amount of the coupler (22) is adjustable; The resonators (21) are each provided with a different resonant frequency, the resonators (21) comprising a first resonant unit (211) and a second resonant unit (212), the first resonant unit (211) and the second resonant unit (212) being connected to the cavity (2) via a coupler (22); The first resonance unit (211) and the second resonance unit (212) are symmetrically arranged in multiple pairs; The resonator (21) is provided with a side wall hole (213), and the side wall hole (213) is connected to the coupler (22) via a connecting rod (4); the coupler (22) comprises a coupling disk (221) and a coupling plate (222) connected to the cavity (2); The coupling piece (222) is provided with a bending body (2222) and a connecting body (2221); The bending body (2222) is a U-shaped structure, one end of which is connected to the cavity (2) and the other end of which is connected to the connecting body (2221); The coupling disc (221) is provided with a through hole (2211) extending therethrough, and the connecting rod (4) is provided through the through hole (2211); an end of the connecting rod (4) away from the side wall hole (213) is connected to the connecting body (2221); Wherein, through the design of the connecting rod (4), the coupling disc (221) can be moved, thereby adjusting the distance between the coupling disc (221) and the connecting body (2221).

2. A band-stop filter according to claim 1, characterized in that: The distance between the coupling sheet (222) and the coupling disk (221) is 1.5 mm to 2.5 mm.

3. A band-stop filter according to claim 1, characterized in that: The cover plate (3) is provided with an opening (31) at a position corresponding to the coupling plate (222); the opening (31) is used to receive an external paddle; the external paddle is used to adjust the distance between the coupling plate (222) and the coupling disk (221).

4. A band-stop filter according to claim 1, characterized in that: The connector (11) comprises a first connector (111) and a second connector (112); the first connector (111) is used to input an external signal, and the second connector (112) is used to output a signal processed by the filter.

5. A band-stop filter according to claim 4, characterized in that: The frequency band of the input signal of the first connector (111) is 50 MHz-3000 MHz, and the frequency band of the output signal of the second connector (112) is 700 MHz-900 MHz.

6. A band-stop filter according to claim 1, characterized in that: The coupling sheet (222) is fixed in the cavity (2) via a metal medium (23).

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