Filter device, communication equipment and base station

Abstract

The invention provides a filter device, communication equipment and a base station, relates to the technical field of communication, and aims to solve the technical problem of poor working performance of the filter device. The filter device comprises a dielectric body and a conductive material covering the outer surface of the dielectric body, the dielectric body comprises a first outer surface and a second outer surface which are deviated from each other in the first direction, a first resonance cavity and a second resonance cavity are formed in the first outer surface at intervals in the second direction, and a coupling groove is formed in the second outer surface. In the second direction, the coupling groove is located between the first resonance cavity and the second resonance cavity, and the projection of the coupling groove in the second direction is not overlapped with the first resonance cavity and the second resonance cavity. In the embodiment provided by the invention, effective coupling between the first resonant cavity and the second resonant cavity can be realized by the coupling groove, and introduction of an extra resonant frequency point at the low end of the passband can be avoided, so that the suppression degree of the low end can be effectively ensured, and the working performance of the filter device can be ensured.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a filtering device, communication equipment and base station. Background Technology

[0002] Filters are an important component of wireless base station equipment. As wireless communication base station equipment develops towards multi-channel and highly integrated designs, the demand for miniaturized, high-performance, and high-power filters is becoming increasingly strong. Among them, dielectric filters are receiving more and more attention due to their miniaturization and high-performance characteristics.

[0003] Dielectric filters are filter devices made of materials with low loss and high relative permittivity (such as ceramics). Dielectric filters typically include mutually coupled resonant structures, which are coupled together through coupling structures. In current dielectric resonators, the coupling structures inevitably introduce parasitic resonances, thus degrading the performance of the dielectric filter. Furthermore, the coupling range achieved by the coupling structures is relatively small, which is not conducive to achieving good coupling effects. Summary of the Invention

[0004] This application provides a filtering device, communication equipment, and base station with good coupling performance.

[0005] In a first aspect, this application provides a filtering device comprising a dielectric body and a conductive material covering the outer surface of the dielectric body. Along a first direction, the outer surface of the dielectric body includes a first outer surface and a second outer surface that are opposite to each other. The filtering device further includes a first resonant cavity, a second resonant cavity, a coupling groove, and a conductive layer. The first and second resonant cavities are spaced apart along a second direction on the first outer surface and are both recessed towards the second outer surface. The first resonant cavity and the dielectric material near it can constitute a first resonant structure. The second resonant cavity and the dielectric material near it can constitute a second resonant structure. The coupling groove is disposed on the second outer surface and is recessed towards the first outer surface. The coupling groove and the dielectric material near it can constitute a coupling structure, which can be used to achieve coupling between the first and second resonant structures. Along the second direction, the coupling groove is located between the first and second resonant cavities, and the projection of the coupling groove in the second direction does not overlap with either the first or second resonant cavity. It should be noted that when the conductive material is covered on the outer surface of the dielectric, it specifically means that the conductive material covers the exposed surface of the dielectric, and the outer surface does not include the inner walls of the first resonant cavity, the second resonant cavity, and the coupling groove.

[0006] In the example provided in this application, by placing the first and second resonant cavities on the first outer surface and the coupling groove on the second outer surface, the coupling groove can generate negative coupling using the capacitance effect, thereby achieving effective coupling between the first and second resonant structures. Furthermore, this structural arrangement does not introduce additional resonant frequencies at the low end of the passband, thus effectively ensuring low-end suppression and contributing to the performance of the filter device. The coupling groove is located on a different surface of the dielectric material from the first and second resonant cavities, allowing for efficient use of the dielectric material's position and facilitating miniaturization of the filter device. Additionally, the projection of the coupling groove in the second direction does not overlap with either the first or second resonant cavities, reducing the magnetic coupling between the first and second resonant structures, improving the coupling effect, and avoiding the introduction of additional resonant frequencies at the low end of the passband, thus effectively ensuring low-end suppression and contributing to the performance of the filter device.

[0007] In one example, the filtering device further includes at least one shielding via. Along a second direction, the at least one shielding via is located between the first resonant cavity and the second resonant cavity, and both ends of the at least one shielding via extend to the first outer surface and the second outer surface, respectively. By providing the shielding via, the magnetic field energy between the first resonant cavity and the second resonant cavity can be effectively shielded. That is, the shielding via can effectively reduce the magnetic coupling between the first resonant structure and the second resonant structure, thereby enabling electric field coupling between the first resonant structure and the second resonant structure through the coupling structure. This can prevent or reduce the introduction of additional resonant frequencies, which is beneficial to improving the operating performance of the filtering device.

[0008] In a specific configuration, the filtering device may include two shielded vias. Along a third direction, the two shielded vias are located on opposite sides of the coupling groove. This third direction is perpendicular to both the first and second directions. Alternatively, it can be understood that the two shielded vias can be located on opposite sides of the coupling groove, thereby effectively balancing the coupling performance of the coupling structure and the shielding performance of the shielded vias.

[0009] In one example, the coupling slot has a convergent portion. In the third direction, the length of the convergent portion is less than the average length of the coupling slot. The shielding via is positioned close to the convergent portion. By providing the convergent portion, other areas of the coupling slot can have larger dimensions, effectively ensuring the coupling effect of the coupling structure. Furthermore, the convergent portion also provides sufficient space for the shielding via, effectively increasing the aperture of the shielding via and thus ensuring its shielding performance.

[0010] In specific configurations, the cross-section of the coupling groove perpendicular to the first direction can be any one of the following: waist-shaped, elliptical, circular, or polygonal.

[0011] In one example, the conductive layer on the second outer surface further includes an annular notch. The annular notch is disposed around the edge of the coupling slot, and there is conductive material on both sides of the annular notch. By providing the annular notch around the coupling slot, the capacitance of the coupling structure can be enhanced, so that a strong negative coupling can be generated due to the capacitance effect, which is beneficial to increasing the coupling effect between the first resonant structure and the second resonant structure.

[0012] In one example, the second outer surface further includes a sunken area recessed toward the first outer surface. The coupling slot is located within the sunken area.

[0013] In one example, the first outer surface and the second outer surface are parallel to each other. Along the first direction, the distance between the first outer surface and the second outer surface is H; along the first direction, the maximum depth of the first resonant cavity and the second resonant cavity is H1; along the first direction, the depth of the coupling slot is H2; wherein, H, H1, and H2 satisfy: H1 + H2 < H. Here, the maximum depth of the first resonant cavity and the second resonant cavity being H1 specifically includes: when the depth dimensions of the first resonant cavity and the second resonant cavity are the same, this H1 is the depth dimension of the first resonant cavity or the second resonant cavity. When the depth dimensions of the first resonant cavity and the second resonant cavity are different, this H1 is the dimension with the largest depth among the first resonant cavity or the second resonant cavity. For example, when the depth dimension of the first resonant cavity is greater than the depth dimension of the second resonant cavity, this H1 is the depth dimension of the first resonant cavity. By reasonably restricting the above H, H1, and H2, the first resonant structure and the second resonant structure can be coupled through an electrical coupling method, and the magnetic coupling amount between the first resonant structure and the second resonant structure can be avoided or reduced, thereby avoiding the introduction of additional resonant points, which is beneficial to ensuring the working performance of the filtering device.

[0014] In a second aspect, the present application further provides a communication device, including a radio frequency circuit and the above-mentioned filtering device. The filtering device is communicatively connected to the radio frequency circuit, and the filtering device can filter and process the electromagnetic waves transmitted in the radio frequency circuit. By adopting the above-mentioned filtering device, the filtering performance of the communication device can be effectively improved, enabling the communication device to have better communication performance.

[0015] In specific settings, the communication device can specifically be an active antenna unit or a radio frequency processing unit, etc.

[0016] In a third aspect, the present application further provides a base station, including an antenna and the above-mentioned communication device. The communication device is communicatively connected to the antenna. The filtering device can filter and process the signals in the radio frequency circuit. By applying the above-mentioned filtering device, the base station can have smaller losses and higher power carrying capacity, and can improve the working performance of the base station.

[0017] The base station mentioned in this application refers to a device that communicates directly with user equipment via a wireless channel. A base station may include various forms of macro base stations, micro base stations, relay stations, access points, or remote radio units. In systems employing different wireless access technologies, the names of devices with base station functions may differ. In this application, the aforementioned devices that communicate directly with user equipment via a wireless channel are collectively referred to as base stations.

[0018] The specific type of base station and the functions implemented are not specifically limited in this application, and the filtering devices provided in the embodiments of this application can also be applied in other devices or scenarios that require the use of filtering devices. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural schematic diagram of a dielectric filter provided in an embodiment of this application;

[0020] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure along the AA direction;

[0021] Figure 3 A three-dimensional structural schematic diagram of a filtering device provided in an embodiment of this application;

[0022] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure along the BB direction;

[0023] Figure 5 for Figure 3 Schematic diagram of the cross-sectional structure along the BB direction;

[0024] Figure 6 A test diagram provided for an embodiment of this application;

[0025] Figure 7 Another test diagram provided for an embodiment of this application;

[0026] Figure 8 A three-dimensional structural schematic diagram of another filtering device provided in an embodiment of this application;

[0027] Figure 9 A schematic diagram of a planar structure of another filtering device provided in an embodiment of this application;

[0028] Figure 10 A schematic diagram of a planar structure of another filtering device provided in an embodiment of this application;

[0029] Figure 11 A three-dimensional structural schematic diagram of another filtering device provided in an embodiment of this application;

[0030] Figure 12A three-dimensional structural schematic diagram of another filtering device provided in an embodiment of this application from another perspective;

[0031] Figure 13 This is a three-dimensional structural schematic diagram of a dielectric filter provided in an embodiment of this application;

[0032] Figure 14 A structural block diagram of an active antenna element provided in an embodiment of this application;

[0033] Figure 15 This is a structural block diagram of a radio frequency processing unit provided in an embodiment of this application. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0035] To facilitate understanding of the filtering devices provided in the embodiments of this application, their application scenarios will be introduced first below.

[0036] The filtering devices provided in this application are specifically dielectric filters, duplexers, or multiplexers. Taking a dielectric filter as an example, a dielectric filter includes a dielectric body and a conductive material covering the outer surface of the dielectric body. The dielectric body is made of a low-loss, high relative permittivity material, such as ceramic. The dielectric filter generally has a rectangular or cylindrical shape. The dielectric filter includes a resonant cavity (or resonant structure), in which electric field energy and magnetic field energy can be converted according to a certain time, which is called an oscillation process, and the oscillation frequency is called the resonant frequency. Due to its advantages such as high quality factor, low insertion loss, small size, and light weight, dielectric filters are widely used in communication fields such as wireless base stations, navigation systems, and satellite communications.

[0037] like Figure 1 and Figure 2As shown, in one example provided in this application, the dielectric filter 01 includes two resonant structures and a coupling structure 013. The two resonant structures are a first resonant structure 011 and a second resonant structure 012, respectively. Specifically, the dielectric filter 01 includes a dielectric body 010 and a conductive material (not shown) covering the outer surface of the dielectric body 010. Two spaced grooves, groove 0111 and groove 0121, are provided on the same surface of the dielectric body 010. The structure formed by groove 0111 and the dielectric material near groove 0111 can be considered as the first resonant structure 011, and the structure formed by groove 0121 and the dielectric material near groove 0121 can be considered as the second resonant structure 012. Additionally, a groove 0131 is provided between groove 0111 and groove 0121, and grooves 0111, 0131, and 0121 are all located on the same surface of the dielectric body 010. The structure formed by groove 0131 and the dielectric material near groove 0131 can be considered as the coupling structure 013. Of course, in some cases, the structure formed by the groove 0131 and the dielectric material near the groove 0131 can also be considered a third resonant structure. When the frequency of this third resonant structure is lower than the resonant frequencies of the first resonant structure 011 and the second resonant structure 012, the third resonant structure can achieve the function of a coupling structure by utilizing polarity reversal. That is, when the resonant frequency of the third resonant structure is much lower than the operating frequency, its function is equivalent to a coupling structure. Figure 1 In the example provided, the groove 0131 and the dielectric material near the groove 0131 constitute a coupling structure 013, which enables coupling between the first resonant structure 011 and the second resonant structure 012.

[0038] In specific configurations, the dimensions of grooves 0111, 0121, and 0131 need to be appropriately set to meet the usage requirements of the dielectric filter 01. For example, the larger the depth or diameter of groove 0131, the lower the resonant frequency of the coupling structure 013. As mentioned above, in order for the coupling structure 013 to effectively couple the first resonant structure 011 and the second resonant structure 012, the resonant frequency of the coupling structure 013 needs to be low. Therefore, the depth or diameter of groove 0131 needs to be much larger than the depth or diameter of grooves 0111 and 0121. That is, the dimensions of groove 0131 are significantly different from those of grooves 0111 and 0121. Consequently, during the molding of the dielectric body 010, problems such as uneven density and poor batch production consistency are likely to occur, affecting the first-pass yield. Furthermore, in practical applications, to ensure the coupling effect between the first resonant structure 011 and the second resonant structure 012, the distance between them is also limited. This restricts the maximum diameter of the groove 0131, resulting in a larger depth dimension, which further worsens the molding difficulty and quality of the dielectric body 010. Additionally, the coupling structure 013 generates a parasitic resonance effect at the low end of the passband when achieving electrical coupling, resulting in poor low-pass suppression. Especially when multiple first resonant structures 011, second resonant structures 012, and coupling structures 013 exist in the dielectric filter 01, the low-pass suppression is significantly weakened, reducing the overall performance of the dielectric filter 01.

[0039] Therefore, embodiments of this application provide a filter device with good coupling effect and good working performance.

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figure 3 As shown, in one example provided in this application, the filter device 10 includes a dielectric body 11 and a conductive material covering the outer surface of the dielectric body 11. Figure 3 (Not shown in the image). The filter device 10 also includes a first resonant structure 12, a second resonant structure 13, and a coupling structure 14. It should be noted that, for ease of understanding of the technical solution of this application, spatial coordinates will be introduced in the following examples to describe the structure of the filter device 10 in detail. These spatial coordinates include a first direction (X-axis), a second direction (Y-axis), and a third direction (Z-axis) that are mutually perpendicular. The term "mutually perpendicular" refers to approximately perpendicularity, meaning that the first direction, the second direction, and the third direction are approximately perpendicular to each other, and not limited to strictly perpendicularity.

[0042] Specifically, such as Figure 3and Figure 4 As shown, in the example provided in this application, the medium 11 is generally a rectangular block. Of course, in other examples, the medium 11 may also be cylindrical, etc., and this application does not limit the shape of the medium 11. In the example provided in this application, the outer surface of the medium 11 includes a first outer surface 111, a second outer surface 112, and four side surfaces connecting the first outer surface 111 and the second outer surface 112. The first outer surface 111 and the second outer surface 112 are both generally planar and are opposite to each other in a first direction. That is, the first outer surface 111 and the second outer surface 112 are both generally perpendicular to the first direction. Of course, in other examples, the first outer surface 111 and the second outer surface 112 may not be parallel. Alternatively, the angle between the first outer surface 111 and the first direction may be less than 90°, and the angle between the second outer surface 112 and the first direction may also be less than 90°. To facilitate understanding of the technical solution of this application, the following example will be provided with the first outer surface 111 and the second outer surface 112 being parallel to each other, and both the first outer surface 111 and the second outer surface 112 being perpendicular to the X-axis.

[0043] Along the Y-axis, a first resonant cavity 121 and a second resonant cavity 131 are spaced apart on the first outer surface 111. Specifically, the first resonant cavity 121 is a groove or blind hole recessed into the second outer surface 112, and the second resonant cavity 131 is also a groove or blind hole recessed into the second outer surface 112. The first resonant cavity 121 and the surrounding dielectric material constitute a first resonant structure 12, and the second resonant cavity 131 and the surrounding dielectric material constitute a second resonant structure 13.

[0044] A coupling groove 141 is disposed on the second outer surface 112 and recessed toward the first outer surface 111. Specifically, the coupling groove 141 is a groove or blind hole recessed toward the first outer surface 111. The coupling groove 141 and the dielectric material nearby constitute a coupling structure 14 for realizing the coupling between the first resonant structure 12 and the second resonant structure 13.

[0045] In practical applications, the outer surface of the dielectric 11 is also covered with a material with good electrical conductivity, such as silver, copper, or aluminum. When electromagnetic waves propagate inside the dielectric 11, they can be filtered by the resonant characteristics of the first resonant structure 12 and the second resonant structure 13. The specific filtering principle is a known existing technology and will not be elaborated here.

[0046] In the example provided in this application, by placing the first resonant cavity 121 and the second resonant cavity 131 on the first outer surface 111 and the coupling groove 141 on the second outer surface 112, the coupling groove 141 can generate negative coupling using the capacitance effect, thereby achieving effective coupling between the first resonant structure 12 and the second resonant structure 13. Furthermore, this structural arrangement does not introduce additional resonant frequencies at the low end of the passband, thus effectively ensuring low-end suppression and contributing to the performance of the filter device 10. Additionally, the coupling groove 141 is located on a different surface of the dielectric body 11 from the first resonant cavity 121 and the second resonant cavity 131, allowing for efficient utilization of the dielectric body 11's position and facilitating the miniaturization design of the filter device 10.

[0047] It should be noted that in the example provided in this application, the first resonant cavity 121 and the second resonant cavity 131 are recessed towards the second outer surface 112 along the X-axis. In other examples, the recess direction of the first resonant cavity 121 or the second resonant cavity 131 may also be at an angle to the X-axis. That is, the first resonant cavity 121 and the second resonant cavity 131 may also be recessed towards the second outer surface 112 in a direction inclined to the X-axis. In addition, the depth dimension and cross-section of the first resonant cavity 121 and the second resonant cavity 131 may be the same or different. For example, the cross-sectional shape of the first resonant cavity 121 and the second resonant cavity 131 may be a circle, an ellipse, or a rectangle, or other shapes, and this application does not limit this. In specific settings, the depth dimension, cross-sectional shape, and cross-sectional size of the first resonant cavity 121 can be reasonably set according to the resonant frequency required by the first resonant structure 12. Accordingly, the depth, cross-sectional shape, and cross-sectional size of the second resonant cavity 131 can be reasonably set according to the resonant frequency required by the second resonant structure 13, which will not be elaborated here.

[0048] Additionally, in the example provided in this application, the coupling groove 141 is recessed along the X-axis toward the first outer surface 111. In other examples, the recessed direction of the coupling groove 141 may also be at an angle to the X-axis. That is, the coupling groove 141 may also be recessed toward the second outer surface 112 in a direction inclined to the X-axis.

[0049] exist Figure 3 and Figure 4 In the example provided, the cross-sectional shape of the coupling groove 141 is rectangular. In other examples, the cross-sectional shape of the coupling groove 141 may also be a circle, an ellipse, a square, or other polygonal shapes.

[0050] When setting the coupling slot 141, the relative positions between the coupling slot 141 and the first resonant cavity 121 and the second resonant cavity 131 can be varied.

[0051] For example, as Figure 3 、 Figure 4 and Figure 5 shown, in an example provided by the present application, along the Y-axis direction, the coupling slot 141 is located between the first resonant cavity 121 and the second resonant cavity 131, and the projection of the coupling slot 141 in the Y-axis direction does not overlap with either the first resonant cavity 121 or the second resonant cavity 131.

[0052] Specifically, in practical applications, most of the magnetic field of the electromagnetic wave will be distributed in the circumferential periphery of the first resonant cavity 121 and the second resonant cavity 131. Most of the electric field will be distributed at the bottom of the first resonant cavity 121 and the second resonant cavity 131.

[0053] In the example provided by the present application, both the first resonant cavity 121 and the second resonant cavity 131 are provided on the first outer surface 111, the coupling slot 141 is provided on the second outer surface 112, and along the Y-axis direction, the coupling slot 141 is provided between the first resonant cavity 121 and the second resonant cavity 131. Therefore, the coupling slot 141 can achieve the coupling between the first resonant structure 12 and the second resonant structure 13 through the way of electric field coupling.

[0054] In addition, along the Y-axis direction, the projection of the coupling slot 141 in the Y-axis direction does not overlap with either the first resonant cavity 121 or the second resonant cavity 131. Therefore, the magnetic coupling amount between the first resonant structure 12 and the second resonant structure 13 can be reduced, the coupling effect between the first resonant structure 12 and the second resonant structure 13 can be improved, and in addition, the introduction of additional resonant frequency points at the low end of the passband can be avoided, so as to effectively ensure the suppression degree at the low end, which is beneficial to ensuring the working performance of the filtering device 10. In addition, the depth dimension of the coupling slot 141 does not need to be set too large. Therefore, when forming the dielectric body 11, problems such as uneven density and poor batch production consistency are not likely to occur, so as to ensure the through rate.

[0055] For example, as Figure 5 shown, in an example provided by the present application, the distance between the first outer surface 111 and the second outer surface 112 is H. The depth of the first resonant cavity 121 and the second resonant cavity 131 is H1, and the depth of the coupling slot 141 is H2; where, H, H1, and H2 satisfy: H1 + H2 < H. Thus, it can be satisfied that the projection of the coupling slot 141 in the Y-axis direction does not overlap with either the first resonant cavity 121 or the second resonant cavity 131.

[0056] In addition, along the Y-axis direction, the distance between the first resonant cavity 121 and the second resonant cavity 131 is L1. The length dimension of the coupling slot 141 along the Y-axis direction is L2. When specifically setting, L1 can be greater than or equal to L2, or L1 can also be less than L2.

[0057] In practical applications, the larger the dimensions (such as depth, length, or width) of the coupling groove 141, the higher the coupling strength. Therefore, in specific settings, the shape and size parameters of the coupling groove 141 can be reasonably set according to actual needs to change the coupling strength of the coupling groove 141. Furthermore, it should be noted that in the example provided in this application, the coupling groove 141 is disposed on the second outer surface 112. Therefore, the size of the dielectric body 11 can be effectively utilized, avoiding or reducing the significant constraints imposed by the first resonant cavity 121 and the second resonant cavity 131 on the size of the coupling groove 141. For example, the depth, length, and width of the coupling groove 141 can be set relatively large, thereby achieving a higher coupling strength.

[0058] In addition, to facilitate understanding of the technical effects of the technical solution in this application, simulation test diagrams are also provided in the embodiments of this application.

[0059] For details, please refer to the following: Figure 6 and Figure 7 .exist Figure 6 In the diagram, the horizontal axis represents... Figure 5 L2 in this context is in mm. Figure 7 In the diagram, the horizontal axis represents... Figure 5 H2 in the figure is in mm. Figure 6 and Figure 7 The vertical axis represents the coupling coefficient. Among them, Figure 6 The curves showing the coupling coefficient of the filter device as a function of L2 are shown. Figure 7 The curve showing the coupling coefficient of the filter device as a function of H2 is shown in the figure.

[0060] from Figure 6 and Figure 7 It is evident that, in practical applications, the coupling coefficient can be enhanced by increasing the dimensions L2 and H2 of the coupling slot 141.

[0061] In addition, a shielding structure is added to the example provided in this application to reduce the magnetic coupling between the first resonant structure 12 and the second resonant structure 13.

[0062] Specifically, such as Figure 8 As shown, the filter device 10 also includes two shielding through holes, namely a first shielding through hole 15 and a second shielding through hole 16, with the two ends of the first shielding through hole 15 and the second shielding through hole 16 extending through to the first outer surface 111 and the second outer surface 112, respectively.

[0063] Along the Y-axis, the first shielding through hole 15 and the second shielding through hole 16 are both located between the first resonant cavity 121 and the second resonant cavity 131, and along the Z-axis, the first shielding through hole 15 and the second shielding through hole 16 are located on both sides of the coupling groove 141.

[0064] In summary, adding a shielding via between the first coupling structure 14 and the second coupling structure 13 can effectively reduce the magnetic coupling between the first resonant structure 12 and the second resonant structure 13, thereby improving the coupling effect between the first coupling structure 14 and the second coupling structure 14. This avoids introducing additional resonant frequencies at the low end of the passband, thus effectively ensuring the low-end suppression and contributing to the performance of the filter device 10.

[0065] In addition, such as Figure 8 and Figure 9 As shown in the example provided in this application, the coupling groove 141 is approximately waist-shaped or butterfly-shaped. That is, the coupling groove 141 has a converging portion, and in the Z-axis direction, the length of the converging portion is less than the average length of the coupling groove 141. The first shielding through hole 15 and the second shielding through hole 16 are disposed close to the converging portion, thereby effectively ensuring the dimensions of the coupling groove 141 and the shielding through hole, and preventing positional interference between the coupling groove 141 and the shielding through hole.

[0066] Alternatively, it can be understood that the larger the diameter of the first shielding through-hole 15 and the second shielding through-hole 16, the better the shielding effect of the first shielding through-hole 15 and the second shielding through-hole 16. Furthermore, the larger the size (such as the width or length) of the coupling groove 141, the better the coupling effect of the coupling structure 14. Therefore, in the example provided in this application, by providing a convergence portion in the coupling groove 141, sufficient space can be reserved in the dielectric body 11 to provide the first shielding through-hole 15 and the second shielding through-hole 16, thereby effectively balancing shielding and coupling performance.

[0067] Of course, the example provided in this application uses two shielding through-holes in the filter device 10 as an example for illustrative purposes. In other examples, the filter device 10 may also include one shielding through-hole, three shielding through-holes, or more shielding through-holes. Furthermore, the cross-section of the coupling groove 141 may also be of a shape other than an oblong shape. In specific configurations, the number, shape, and position of the shielding through-holes can be reasonably set according to actual needs. Correspondingly, the shape of the coupling groove 141 and the relative position between the coupling groove 141 and the shielding through-holes can also be flexibly set according to actual needs, and will not be elaborated here.

[0068] In addition, such as Figure 10As shown, in one example provided in this application, the conductive layer 101 of the second outer surface 112 also includes an annular notch 17. The annular notch 17 is disposed around the edge of the coupling groove 141, and both sides of the annular notch 17 have conductive material. By setting the annular notch 17, the capacitance of the coupling structure 14 can be improved, thereby generating a stronger negative coupling due to the capacitive effect, which is beneficial to increasing the coupling effect between the first resonant structure 14 and the second resonant structure 13. In specific settings, the capacitance of the coupling structure 14 can be reasonably adjusted by reasonably setting parameters such as the width and shape of the annular notch 17. In addition, the distance between the annular notch 17 and the coupling groove 141 can also be reasonably set according to the actual situation, which will not be elaborated here.

[0069] In addition, such as Figure 11 and Figure 12 As shown, in one example provided in this application, the second outer surface 112 further includes a recessed region 18 that is recessed toward the first outer surface 111. The coupling groove 141 is located within the recessed region 18.

[0070] In specific configurations, the aforementioned annular notch 17 can be placed within the space of the recessed area 18. Additionally, in some examples, aluminum foil or other metal materials can be used to cover the recessed area 18 to prevent electromagnetic waves from leaking outwards from the annular notch 17, thereby ensuring the operational performance of the filter device 10. Alternatively, it can be understood that by placing the annular notch 17 in the recessed area 18 and covering the recessed area 18 with a thin metal sheet such as aluminum foil, electromagnetic waves can be prevented from leaking outwards from the annular notch 17, while also ensuring the flatness of the filter device 10 on the second surface 112.

[0071] It should be noted that the outer surface of the dielectric body 11 refers to all exposed outer surfaces of the dielectric body 11. This outer surface does not include the exposed surfaces (or inner walls) of the first resonant cavity 121, the second resonant cavity 131, and the coupling groove 141. Furthermore, this outer surface also does not include the exposed surfaces (or inner walls) of the first shielding through-hole 15 and the second shielding through-hole 16. Additionally, in some examples, when the second outer surface 112 includes a recessed area 18, this outer surface may or may not include the exposed surface of the recessed area 18. Alternatively, it can be understood that the recessed area 18 may or may not be covered with conductive material. Furthermore, the annular notch 17 may also be located within the conductive material of the recessed area 18.

[0072] It should be noted that the above example is exemplified by the filter device 10 including a first resonant structure 12 and a second resonant structure 13 that are coupled to each other, as well as a coupling structure 14 for realizing the coupling. In other examples, the filter device 10 may also include more mutually coupled resonant structures, as well as a coupling structure 14 for realizing the coupling between two resonant structures.

[0073] For example, such as Figure 13 As shown, in a dielectric filter 20 provided in this application, there are including Figure 11 The filter device 10 shown also includes some conventional types of resonant structures and coupling structures.

[0074] Specifically, the dielectric filter 20 includes a filter element 10, eight resonant structures, and five coupling structures. The eight resonant structures are resonant structures 21a, 21b, 21c, 21d, 21e, 21f, 21g, and 21h. The five coupling structures are coupling structures 22a, 22b, 22c, 22d, and 22e. Coupling structure 22a is used to couple resonant structures 21a and 21b. Coupling structure 22b is divided into two parts: one part couples resonant structures 21b and 21c, and the other part couples the first resonant structure 12 and resonant structure 21g in the filter element 10. Coupling structure 22c couples resonant structures 21c and 21d. The coupling structure 22d is divided into three parts: one part is used to achieve coupling between resonant structure 21d and resonant structure 21e; ​​another part is used to achieve coupling between resonant structure 21e and resonant structure 21f; and the third part is used to achieve coupling between resonant structure 21f and the second resonant structure 13 in filter device 10.

[0075] Alternatively, it can be understood that the dielectric filter 20 achieves its filtering function by relying on the coupling between multiple resonant structures.

[0076] It should be noted that, in Figure 13 The example provided illustrates a dielectric filter 20 comprising one filter element 10. In other examples, the dielectric filter 20 may include two or more filter elements 20. In specific configurations, the number and type of resonant and coupling structures included in the dielectric filter 20 can be reasonably set according to actual needs, which will not be elaborated here.

[0077] In practical applications, the filtering device can be a filter, multiplexer, etc. This application does not limit the specific type of filtering device.

[0078] In addition, in specific settings, the filtering device can also be a duplexer, tripplexer, or other multiplexer. This application does not limit the specific type of filtering device.

[0079] In practical applications, filtering devices can be used in a variety of communication devices that have filtering requirements.

[0080] For example, such as Figure 14 As shown in one example provided in this application, the communication device is specifically an active antenna unit (AAU). Simply put, the AAU includes a radio unit (RU), an antenna, and a power supply. The radio unit is used to process uplink and downlink radio frequency signals and can also perform functions such as phase correction of the radio frequency channel. The antenna can be a large-scale antenna array to achieve wireless signal transmission and reception. Of course, in practical applications, the specific type of antenna is not limited in this application. The power supply can provide power to some electrical components in the radio unit and the antenna.

[0081] The radio frequency (RF) unit may include an interface module, a digital-to-analog converter (DAC), RF components, a power amplifier (PA), and filtering devices. The interface module can be of the type supporting CPPI (CPU peripheral interface) communication or used to transmit digital intermediate frequency (IF) signals. The DAC is used to convert between analog and digital signals. The filtering devices can be of any type shown in the examples above.

[0082] It is understandable that AAU is a commonly used communication device. Therefore, the specific structure and working principle of AAU will not be described in detail in the examples provided in this application.

[0083] Or, such as Figure 15As shown, in another example provided in this application, the communication device can specifically be a remote radio unit (RRU). Simply put, the RRU can be used to select, amplify, and down-convert the signal received by the antenna, converting it into an intermediate frequency (IF) signal or a baseband signal and sending it to the baseband processing unit. Alternatively, the RRU can be used to up-convert and amplify the IF signal emitted by the baseband processing unit, converting it into a wireless signal through the antenna and transmitting it. The RRU may include a high-speed interface module, a signal processing unit, a power amplifier unit, a duplexer unit, and a power supply. The signal processing unit includes a transmitter (TX) and a receiver (RX). The transmitter converts the signal into electromagnetic waves and transmits it through the antenna. In this process, the power amplifier (PA) amplifies the weak RRU signal, enabling it to propagate over a longer distance. The receiver receives the electromagnetic wave signal from a distant location and converts it back into the original signal. At the receiving end, a low-noise amplifier (LNA) amplifies the received weak signal. Of course, during transmission and reception, the two duplexers in the duplexer unit can perform filtering and other processing on the uplink and downlink signals respectively. The filtering devices provided in the embodiments of this application can all be used as duplexers.

[0084] It is understandable that radio frequency (RF) processing units are a commonly used type of communication device. Therefore, the specific structure and working principle of the RF processing unit will not be described in detail in the examples provided in this application.

[0085] In addition, this application also provides a base station, which includes the filtering devices, active antenna units, or radio frequency processing units described in the above embodiments. The radio frequency circuit in the base station is communicatively connected to the filtering devices, enabling the filtering devices to perform filtering and other processing on the signals generated by the radio frequency circuit. Of course, in other examples, the base station may also include antennas and other devices. In practical applications, the type and quantity of electronic devices included in the base station can be reasonably set according to actual needs. The base station mentioned in this application refers to a device that communicates directly with user equipment through a wireless channel. The base station may include various forms of macro base stations, micro base stations, relay stations, access points, or radio frequency remote units. In systems using different wireless access technologies, the names of devices with base station functions may differ. In this application, the aforementioned devices that communicate directly with user equipment through a wireless channel are collectively referred to as base stations.

[0086] The specific type of base station and the functions implemented are not specifically limited in this application, and the filtering devices provided in the embodiments of this application can also be applied in other devices or scenarios that require the use of filtering devices.

[0087] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0088] In this application, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural.

[0089] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A filter device, characterized by The medium body comprises a first outer surface and a second outer surface facing away from each other in a first direction; The filter device further comprises a first resonant cavity, a second resonant cavity, a coupling slot and a conductive layer; The first resonant cavity and the second resonant cavity are arranged on the first outer surface and are recessed towards the second outer surface in a second direction; The coupling slot is arranged on the second outer surface and is recessed towards the first outer surface; The conductive layer covers the outer surface of the medium body; In the second direction, the coupling slot is located between the first resonant cavity and the second resonant cavity, and the projection of the coupling slot in the second direction does not overlap with the first resonant cavity and the second resonant cavity.

2. The filter device of claim 1, wherein, The filter device further comprises at least one shielding through hole; In the second direction, the at least one shielding through hole is located between the first resonant cavity and the second resonant cavity, and the two ends of the at least one shielding hole respectively extend to the first outer surface and the second outer surface.

3. The filter device of claim 2, wherein, The filter device comprises two shielding through holes; In a third direction, the two shielding through holes are respectively located on the two sides of the coupling slot; The third direction is perpendicular to the first direction and the second direction.

4. The filter device according to claim 2 or 3, characterized in that In the second direction, the coupling slot has a converging part; In the third direction, the length of the converging part is less than the average length of the coupling slot; The shielding through hole is arranged close to the converging part.

5. The filter device according to any one of claims 1 to 4, characterized in that, The cross section of the coupling slot perpendicular to the first direction is a waist shape, an elliptical shape, a circular shape or a polygonal shape.

6. The filter device of any one of claims 1 to 5, wherein, The conductive layer of the second outer surface further comprises an annular notch; The annular notch is arranged around the edge of the coupling slot, and both sides of the annular notch have conductive material.

7. The filter device of any one of claims 1 to 6, wherein, The second outer surface further comprises a sunken area recessed towards the first outer surface; The coupling slot is located in the sunken area.

8. The filter device of any one of claims 1 to 7, wherein, The first outer surface and the second outer surface are parallel to each other; In the first direction, the distance between the first outer surface and the second outer surface is H; In the first direction, the maximum depth of the first resonant cavity and the second resonant cavity is H1; In the first direction, the depth of the coupling slot is H2; Wherein, H, H1 and H2 satisfy: H1+H2<H.

9. A communication device, characterized by The filter device as claimed in any one of claims 1 to 8 is in communication connection with the radio frequency circuit.

10. The communication device of claim 9, wherein, The communication device is an active antenna unit or a radio frequency processing unit.

11. A base station, characterized by The communication device as claimed in claim 9 or 10 is in communication connection with the antenna. The communication device as claimed in claim 9 or 10 is in communication connection with the antenna.

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