Band elimination filter based on HTCC

Abstract

The invention provides a band elimination filter based on an HTCC, and the filter comprises a laminated body, the laminated body comprises a plurality of dielectric layers which are arranged in a laminated manner, and the outer surface of the laminated body is provided with an input end, an output end, and a grounding end. A first inductor, a second inductor, a third inductor, a first capacitor, a second capacitor, a third capacitor and a fourth capacitor are arranged in the laminated body, the first inductor and the first capacitor are connected in parallel to form a first parallel resonance unit, and the second inductor and the second capacitor are connected in parallel to form a second parallel resonance unit; the first parallel resonance unit and the second parallel resonance unit are connected between the input end and the output end in series, and one end of the third parallel resonance unit is connected to the joint of the first parallel resonance unit and the second parallel resonance unit. The other end of the third parallel resonance unit is connected with the grounding end through a fourth capacitor; two adjacent annular electrodes in the third inductor are connected through an electrode part, so that the third inductor is of a three-dimensional gyroscope structure.

Description

Technical Field

[0001] This application relates to the field of band-stop filter technology, and in particular to a band-stop filter based on HTCC. Background Technology

[0002] A band-stop filter is a filter that allows most frequency components to pass through, but attenuates certain frequency components to extremely low levels. In high-frequency fields such as 5G communication, satellite navigation, and electronic systems, the refined utilization of spectrum resources has made adjacent-channel interference increasingly prominent, seriously affecting the signal-to-noise ratio and reliability of the system. As a key component for suppressing interference in specific frequency bands, the performance of band-stop filters is crucial.

[0003] In related technologies, band-stop filters have been miniaturized using high-temperature cofired ceramics (HTCC) technology. However, with the development of mobile communication technology, spectrum resources are becoming increasingly congested, and interference is becoming more severe, making it impossible to simultaneously achieve small area and high performance (high-frequency band, ultra-narrowband suppression). Summary of the Invention

[0004] This application provides an HTCC-based bandstop filter to address the problem that related bandstop filters cannot simultaneously achieve miniaturization and high performance.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: This application provides a band-stop filter based on HTCC, including a stacked body comprising multiple dielectric layers stacked together. The outer surface of the stacked body has an input terminal, an output terminal, and a ground terminal. The stacked body contains a first inductor, a second inductor, a third inductor, a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor. The first inductor and the first capacitor are connected in parallel to form a first parallel resonant unit; the second inductor and the second capacitor are connected in parallel to form a second parallel resonant unit; and the third inductor is connected in series with the third capacitor to form a third parallel resonant unit. The first and second parallel resonant units are connected in series between the input terminal and the output terminal. One end of the third parallel resonant unit is connected to the connection point between the first and second parallel resonant units, and the other end of the third parallel resonant unit is connected to the ground terminal through the fourth capacitor. The third inductor includes multiple annular electrodes and electrode portions coaxially arranged along the stacking direction. The electrode portions penetrate the dielectric layers, and adjacent annular electrodes are connected through the electrode portions, so that the third inductor has a three-dimensional gyroscope structure.

[0006] In some implementations, the third inductor includes a first inductor electrode and a second inductor electrode coaxially arranged along the stacking direction. The second inductor electrode is connected in series with the first inductor electrode and is connected between the first inductor electrode and the ground terminal. The second inductor electrode includes at least two ring electrodes and an electrode portion. The ring electrodes have openings, and the opening directions of two adjacent ring electrodes are different. Along the stacking direction from the top layer to the bottom layer of the stack, the inner diameter of the ring electrodes decreases so that the orthographic projection profile of the second inductor electrode on the dielectric layer is helical.

[0007] In some implementations, the first inductor electrode includes a plurality of the aforementioned annular electrodes and the electrode portion, wherein the annular electrodes have openings and the opening directions of adjacent annular electrodes are different; the inner diameter of the annular electrodes increases along the stacking direction from the top layer to the bottom layer of the stack, such that the orthographic projection profile of the first inductor electrode on the dielectric layer is helical; the annular electrode with the largest inner diameter of the first inductor electrode is close to and connected to the annular electrode with the largest inner diameter of the second inductor electrode.

[0008] In some implementations, the first inductor electrode has a planar spiral structure; or, the first inductor electrode has a planar closed ring structure.

[0009] In some implementations, the outline shape of the annular electrode is any one of a rectangular ring, a circular ring, or a polygonal ring.

[0010] In some implementations, at least a portion of the annular electrodes have the same inner diameter; and / or, at least a portion of the annular electrodes have the same linewidth.

[0011] In some implementations, the stacked body is a cuboid structure. The input terminal and the output terminal are located at both ends of the stacked body along its length. The grounding terminal includes a first grounding electrode, a second grounding electrode, and a third grounding electrode. The first grounding electrode and the second grounding electrode are located at both ends of the stacked body along its width. The third grounding electrode is connected between the first grounding electrode and the second grounding electrode. Along the height direction of the stacked body, the third grounding electrode is located on the side surface closer to the third inductor. The third inductor and the third grounding electrode couple to form a parasitic capacitance, which is the fourth capacitor.

[0012] In some implementations, the first inductor is a planar ring electrode, the second inductor has a planar ring structure, and the first inductor and the second inductor are disposed on the same layer.

[0013] In some implementations, the first capacitor is a vertically interdigitated capacitor, and the second capacitor is a vertically interdigitated capacitor; and / or, the first capacitor and the second capacitor are disposed on the same layer.

[0014] In some implementations, the stacked body is a cuboid structure, the length of the band-stop filter is 4.50±0.1mm, the width of the band-stop filter is 3.20±0.1mm, and the height of the band-stop filter is 1.50±0.1mm.

[0015] The beneficial effects of the band-stop filter provided in this application are as follows: Compared with related technologies, this application uses three inductors and four capacitors to form three parallel resonant units. The first and second parallel resonant units are connected in series between the input and output terminals. One end of the third parallel resonant unit is connected to the junction of the first and second parallel resonant units, and the other end is connected to the ground terminal through the fourth capacitor. Furthermore, compared to inductors using planar or three-dimensional spiral structures, the third inductor in this band-stop filter has a three-dimensional gyroscope structure. This reduces the area occupied by the ring electrodes on each dielectric layer. Firstly, it significantly reduces the interlayer coupling area, thereby effectively compressing the parasitic capacitance between the third inductor and the ground terminal from the structural source. This makes it easier to achieve… With the same inductance value, the self-resonant frequency of the third inductor in the 3D gyroscope structure is significantly increased. A higher self-resonant frequency means that the third inductor can operate effectively in a higher frequency band without losing its inductance characteristics due to parasitic capacitance. Secondly, low parasitic capacitance means that less energy is shunted by the capacitor near the resonant frequency, and more energy is stored in the magnetic field, thereby improving the effective Q value. A higher Q value directly translates into deeper stopband rejection and lower passband insertion loss in the bandstop filter, resulting in better bandstop filter performance. Thirdly, the area of ​​the dielectric layer is effectively reduced, which helps to reduce the area of ​​the stacked body in the cross-section perpendicular to the stacking direction of the dielectric layer, thereby achieving a smaller area and enabling the bandstop filter to achieve both a small area and better performance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a band-stop filter provided in an embodiment of this application; Figure 2A schematic diagram of the structure of the stacked body and the portion of the band-stop filter with an external connection terminal provided in the embodiments of this application; Figure 3 The circuit schematic of the band-stop filter provided in the embodiments of this application; Figure 4 A structural diagram of the electrodes disposed inside the laminate provided in the embodiments of this application; Figure 5 for Figure 1 A structural diagram of a band-stop filter in a given view. Figure 6 for Figure 1 A structural diagram of a band-stop filter from another perspective; Figure 7 Insertion loss curve of the band-stop filter provided in the embodiments of this application; Figure 8 The return loss curve of the band-stop filter provided in the embodiments of this application is shown.

[0018] Figure label: 10. Laminated body; 11. Input terminal; 12. Input terminal; 13. Grounding terminal; 131. First grounding electrode; 132. Second grounding electrode; 133. Third grounding electrode; 21. First resonant unit; 22. Second resonant unit; 23. Third resonant unit; First inductor L1; Second inductor L2; Third inductor L3; First inductor electrode L31; Second inductor electrode L32; First capacitor C1; Second capacitor C2; Third capacitor C3; Fourth capacitor C4. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, as fixed connection, detachable connection, or integral connection; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] A band-stop filter is a filter that allows most frequency components to pass through, but attenuates certain frequency components to extremely low levels. In high-frequency fields such as 5G communication, satellite navigation, and electronic systems, the refined utilization of spectrum resources has made adjacent-channel interference increasingly prominent, seriously affecting the signal-to-noise ratio and reliability of the system. As a key component for suppressing interference in specific frequency bands, the performance of band-stop filters is crucial.

[0024] In related technologies, band-stop filters have achieved miniaturization using low-temperature co-fired ceramic (HTCC) technology. However, with the development of mobile communication technology, spectrum resources are becoming increasingly congested, and interference is becoming more severe, making it impossible to simultaneously achieve high performance such as small area, high frequency band, and ultra-narrowband suppression.

[0025] To address the aforementioned issues, this application provides a band-stop filter.

[0026] The aforementioned band-stop filter is based on High Temperature Corfired Ceramics (HTCC) technology.

[0027] refer to Figures 1 to 4The band-stop filter includes a stacked body 10, which comprises multiple dielectric layers stacked together. The outer surface of the stacked body 10 has an input terminal 11, an output terminal 12, and a ground terminal 13. The stacked body 10 contains a first inductor L1, a second inductor L2, a third inductor L3, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4. The first inductor L1 and the first capacitor C1 are connected in parallel to form a first parallel resonant unit 21. The second inductor L2 and the second capacitor C2 are connected in parallel to form a second parallel resonant unit 22. The third inductor L3 is connected in series with the third capacitor C3 to form a second parallel resonant unit 22. The third parallel resonant unit 23 is formed. The first parallel resonant unit 21 and the second parallel resonant unit 22 are connected in series between the input terminal 11 and the output terminal 12. One end of the third parallel resonant unit 23 is connected to the connection between the first parallel resonant unit 21 and the second parallel resonant unit 22. The other end of the third parallel resonant unit 23 is connected to the ground terminal 13 through the fourth capacitor C4. The third inductor L3 includes a plurality of ring electrodes and electrode portions arranged coaxially along the stacking direction. The electrode portions penetrate the dielectric layer. Two adjacent ring electrodes are connected through the electrode portions so that the third inductor L3 has a three-dimensional gyroscope structure.

[0028] The dielectric layer in the stack 10 is made of ceramic, with a dielectric constant of 8.7 and a dielectric loss factor tanα ≤ 0.002.

[0029] The above-mentioned parallel resonant unit is an LC resonant unit.

[0030] The aforementioned fourth capacitor C4 may be, but is not limited to, a parasitic capacitance generated by the parasitic effect between the third inductor L3 and the ground terminal 13.

[0031] The aforementioned three-dimensional gyroscope structure, along with the planar spiral structure, comprises electrodes disposed on at least three dielectric layers. The final coil shape, especially in cross-section, resembles a gyroscope. That is, the coils formed by the electrodes on each dielectric layer are interwoven in three-dimensional space, forming a stable three-dimensional gyroscope structure. This includes situations where each dielectric layer has one electrode, which is essentially ring-shaped, and multiple electrodes on different dielectric layers are interwoven in three-dimensional space. It also includes situations where a planar spiral electrode is located on one dielectric layer, and a ring-shaped electrode is located on a number of dielectric layers, interwoven in three-dimensional space and connected in series with a planar spiral inductor to form a structure similar to a three-dimensional gyroscope. The third inductor, L3, is a ground-to-ground inductor. Designing L3 as a three-dimensional gyroscope structure results in coaxial magnetic field coupling between the ring-shaped electrodes, a small parallel overlap area, and significantly lower interlayer parasitic capacitance compared to a three-dimensional spiral inductor composed of multiple planar inductors. Each dielectric layer incorporates a planar spiral inductor, which, compared to a three-dimensional spiral inductor composed of multiple planar inductors, results in a shorter total coil length with the same number of dielectric layers. This shorter coil length reduces the skin effect, and the three-dimensional gyroscope structure reduces proximity effect and parasitic capacitance. These three factors combined achieve an extremely high Q value. Furthermore, the high inductance value is achieved through vertical stacking, with a much lower inductance density per unit area on the dielectric layer compared to all planar inductors. This not only facilitates the miniaturization and high-density integration of band-stop filters but also drastically reduces AC resistance and proximity effect losses.

[0032] The circuit principle of this band-stop filter is as follows: Figure 3 As shown.

[0033] This application comprises three parallel resonant units consisting of three inductors and four capacitors. The first parallel resonant unit 21 and the second parallel resonant unit 22 are connected in series between the input terminal 11 and the output terminal 12. One end of the third parallel resonant unit 23 is connected to the junction of the first parallel resonant unit 21 and the second parallel resonant unit 22, and the other end of the third parallel resonant unit 23 is connected to the ground terminal 13 via the fourth capacitor C4. Furthermore, compared to inductors employing planar or three-dimensional spiral structures, the third inductor L3 in this resistive inductor has a three-dimensional gyroscope structure. This reduces the area occupied by the ring electrodes on each dielectric layer, significantly reducing the interlayer coupling area and effectively compressing the parasitic capacitance between the third inductor L3 and the ground terminal 13 from the structural source. This allows for the achievement of the same inductance... Under the condition of low self-resonance, the self-resonance frequency of the third inductor L3 in the three-dimensional gyroscope structure is greatly improved. The higher self-resonance frequency means that the third inductor L3 can work effectively in a higher frequency band without losing its inductive characteristics due to parasitic capacitance. Secondly, low parasitic capacitance means that less energy is shunted by the capacitor near the resonant frequency, and more energy is stored in the magnetic field, thereby improving the effective Q value. The higher Q value directly translates into deeper stopband rejection and lower passband insertion loss of the bandstop filter, resulting in better performance of the bandstop filter. Thirdly, the area of ​​the dielectric layer is effectively reduced, which helps to reduce the area of ​​the stack 10 in the cross-section perpendicular to the stacking direction of the dielectric layer, thereby achieving a small area and enabling the bandstop filter to achieve both small area and better performance.

[0034] refer to Figure 2 In this embodiment, the stacked body 10 has a cuboid structure. The input terminal 11 and the output terminal 12 are located at both ends of the stacked body 10 along its length. The grounding terminal 13 includes a first grounding electrode 131, a second grounding electrode 132, and a third grounding electrode 133. The first grounding electrode 131 and the second grounding electrode 132 are located at both ends of the stacked body 10 along its width. The third grounding electrode 133 is connected between the first grounding electrode 131 and the second grounding electrode 132. Along the height direction of the stacked body 10, the third grounding electrode 133 is located on the surface near the third inductor L3. The third inductor L3 and the third grounding electrode 133 are coupled to form a parasitic capacitance, which is the fourth capacitor C4. This configuration effectively reduces the fourth capacitor C4, which is beneficial for narrowing the actual bandwidth of the band-stop filter.

[0035] refer to Figure 1 and Figure 4In this embodiment, the third inductor L3 includes a first inductor electrode L31 and a second inductor electrode L32 coaxially arranged along the stacking direction. The second inductor electrode L32 is connected in series with the first inductor electrode L31. The second inductor L2 is connected between the first inductor electrode L31 and the ground terminal 13. The second inductor electrode L32 includes at least two annular electrodes and electrode portions. The annular electrodes have openings, and the opening directions of two adjacent annular electrodes are different. Along the stacking direction from the top layer to the bottom layer of the stack 10, the inner diameter of the annular electrodes decreases so that the orthographic projection profile of the second inductor electrode L32 on the dielectric layer is spiral.

[0036] The outline shape of the aforementioned annular electrode can be any one of a rectangular ring, a circular ring, or a polygonal ring. If the outline shape of the annular electrode is a circular ring, then the inner diameter of the annular structure is clear. In the embodiments of this application, the outline shape of the annular structure is a rectangular ring or a structure similar to a rectangular ring. Therefore, this inner diameter refers to the diameter of the smallest envelope circle, or in other words, the diameter of the approximate circle formed by the innermost points of the annular electrode.

[0037] refer to Figure 1 and Figure 4 In some feasible implementations, the first inductor electrode L31 includes multiple annular electrodes and electrode portions. The annular electrodes have openings, and the opening directions of adjacent annular electrodes are different. Along the stacking direction from the top to the bottom of the stack 10, the inner diameter of the annular electrodes increases, so that the orthographic projection profile of the first inductor electrode L31 on the dielectric layer is spiral-shaped. The annular electrode with the largest inner diameter of the first inductor electrode L31 is close to and connected to the annular electrode with the largest inner diameter in the second inductor electrode L32. That is, along the stacking direction, the inner diameter of the electrode of the third inductor L3 first increases and then decreases, forming an overall three-dimensional gyroscope structure. This further effectively reduces the parasitic capacitance of the third inductor L3 to ground.

[0038] refer to Figure 1 and Figure 3 In this embodiment, the first inductor electrode L31 has a planar closed ring structure, which enables miniaturization. Of course, if the size requirements of the band-stop filter are not high, the first inductor electrode L31 can also have a planar spiral structure; no specific limitation is made here.

[0039] refer to Figure 1 In this embodiment, at least a portion of the annular electrodes have the same inner diameter. This makes the structure of the dielectric layer where the electrodes are partially disposed identical, thus simplifying the manufacturing process and saving costs.

[0040] At least a portion of the ring electrodes include all ring electrodes and a portion of them. That is, all ring electrodes can have the same linewidth, or only a portion of the ring electrodes can have the same linewidth, while the rest have different linewidths. This simplifies the process and reduces costs.

[0041] refer to Figure 1 In this embodiment, the first inductor L1 is a planar ring electrode, and the second inductor L2 has a planar ring structure; the first inductor L1 and the second inductor L2 are disposed in the same layer. This reduces the use of the dielectric layer, which is beneficial for improving the utilization rate of the dielectric layer in the stack 10, thereby reducing the volume of the stack 10. The first capacitor C1 is a vertically interdigitated capacitor, and the second capacitor C2 is a vertically interdigitated capacitor; the first capacitor C1 and the second capacitor C2 are disposed in the same layer. This further reduces the volume of the stack 10.

[0042] The outline shape and size of the first inductor L1 and the second inductor L2 can be the same. This simplifies the manufacturing process.

[0043] The aforementioned vertical interdigital capacitor refers to the use of the vertical dimension of multiple dielectric layers. By vertically overlapping and horizontally interlacing the finger-like components of two comb-shaped electrodes located on different dielectric layers within the three-dimensional space of the stack 10, the effective coupling area between the electrodes is significantly increased, resulting in higher self-resonance and thus superior overall performance. It is suitable for higher frequency applications.

[0044] In this embodiment of the application, the band-stop filter has a cuboid structure in its stack 10. The length of the band-stop filter is 4.50±0.1mm, the width is 3.20±0.1mm, and the height is 1.50±0.1mm. The third inductor L3 adopts a three-dimensional gyroscope structure. The first inductor L1 and the second inductor L2 are in a ring structure and are arranged in the same layer. The inner electrodes of the first inductor L1, the second inductor L2, and the third inductor L3 are made of low-temperature silver paste with a sintering temperature ≤900℃, a silver content of 85%±10%, and a silver layer thickness of 10±3μm. The terminal electrodes of the input terminal 11, the output terminal 12, and the ground terminal 13 are composed of a three-layer structure. The innermost layer is silver paste with a silver content of 60%±20% and a sintering temperature ≤800℃. The middle layer is a nickel layer, and the outermost layer is a tin layer. This minimizes the parasitic capacitance of the ground inductance, i.e., the third inductance L3, increases the steepness of the resonant point, and compresses the stopband bandwidth to 60% of that in traditional designs, thereby effectively compressing the stopband bandwidth of the bandstop filter.

[0045] After simulation, the insertion loss curve is as follows: Figure 7 As shown, the product return loss curve is as follows: Figure 8As shown. The insertion loss in the passband is ≤3.4dB@10MHz~1150MHz, ≤4.3dB@1350MHz~2300MHz, and the return loss is ≥30dB@1250MHz.

[0046] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An HTCC-based bandstop filter, characterized by, include: The stack (10) includes multiple dielectric layers stacked together, and the outer surface of the stack (10) is provided with an input terminal (11), an output terminal (12) and a ground terminal (13). The stacked body (10) is provided with a first inductor, a second inductor, a third inductor, a first capacitor, a second capacitor, a third capacitor and a fourth capacitor. The first inductor and the first capacitor are connected in parallel to form a first parallel resonant unit (21). The second inductor and the second capacitor are connected in parallel to form a second parallel resonant unit (22). The third inductor is connected in series with the third capacitor to form a third parallel resonant unit (23). The first parallel resonant unit (21) and the second parallel resonant unit (22) are connected in series between the input terminal (11) and the output terminal (12). One end of the third parallel resonant unit (23) is connected to the connection between the first parallel resonant unit (21) and the second parallel resonant unit (22). The other end of the third parallel resonant unit (23) is connected to the ground terminal (13) through the fourth capacitor. The third inductor includes a plurality of annular electrodes and electrode portions arranged coaxially along the stacking direction. The electrode portions penetrate the dielectric layer, and two adjacent annular electrodes are connected through the electrode portions, so that the third inductor has a three-dimensional gyroscope structure.

2. The band-stop filter according to claim 1, characterized in that, The third inductor includes a first inductor electrode and a second inductor electrode arranged coaxially along the stacking direction. The second inductor electrode is connected in series with the first inductor electrode. The second inductor is connected between the first inductor electrode and the ground terminal (13). The second inductor electrode includes at least two ring electrodes and an electrode portion. The ring electrodes have openings, and the opening directions of two adjacent ring electrodes are different. Along the stacking direction from the top layer to the bottom layer of the stack (10), the inner diameter of the ring electrodes decreases so that the orthographic projection profile of the second inductor electrode on the dielectric layer is spiral.

3. The band-stop filter according to claim 2, characterized in that, The first inductor electrode includes a plurality of the ring electrodes and the electrode portion, wherein the ring electrodes have openings and the opening directions of two adjacent ring electrodes are different; Along the stacking direction from the top layer to the bottom layer of the stack (10), the inner diameter of the annular electrode increases so that the orthographic projection profile of the first inductor electrode on the dielectric layer is spiral; the annular electrode with the largest inner diameter of the first inductor electrode is close to and connected to the annular electrode with the largest inner diameter of the second inductor electrode.

4. The band-stop filter according to claim 2, characterized in that, The first inductor electrode has a planar spiral structure; Alternatively, the first inductor electrode may have a planar closed ring structure.

5. The band-stop filter according to any one of claims 1-4, characterized in that, The outline shape of the ring electrode can be any one of a rectangular ring, a circular ring, or a polygonal ring.

6. The bandstop filter according to any one of claims 1-4, wherein, the inner diameter of at least some of the ring electrodes is the same; and / or, the line width of at least some of the ring electrodes is the same.

7. The bandstop filter according to any one of claims 1-4, wherein, the laminated body (10) is a cuboid structure, the input end (11) and the output end (12) are arranged at two ends of the laminated body (10) along the length direction of the laminated body (10), the ground end (13) includes a first ground electrode (131), a second ground electrode (132), and a third ground electrode (133), the first ground electrode (131) and the second ground electrode (132) are arranged at two ends of the laminated body (10) along the width direction of the laminated body (10), the third ground electrode (133) is connected between the first ground electrode (131) and the second ground electrode (132), along the height direction of the laminated body (10), the third ground electrode (133) is located on the side surface close to the third inductor, and the third inductor and the third ground electrode (133) are coupled to form a parasitic capacitor as the fourth capacitor.

8. The bandstop filter according to any one of claims 1-4, wherein, the first inductor is a planar ring electrode, the second inductor is a planar ring electrode, and the first inductor and the second inductor are arranged in the same layer.

9. The bandstop filter according to any one of claims 1-4, wherein, the first capacitor is a vertical interdigital capacitor, and the second capacitor is a vertical interdigital capacitor; and / or, the first capacitor and the second capacitor are arranged in the same layer.

10. The bandstop filter according to any one of claims 1-4, wherein, the laminated body (10) is a cuboid structure, the length of the bandstop filter is 4.50±0.1 mm, the width of the bandstop filter is 3.20±0.1 mm, and the height of the bandstop filter is 1.50±0.1 mm.

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