Dielectric filter and communication apparatus

Abstract

Embodiments of this application provide a dielectric filter and a communication apparatus. The dielectric filter includes a dielectric body, and the dielectric body is provided with at least a first resonance blind via located on a first side surface and a second resonance blind via located on a second side surface. The first resonance blind via and the dielectric body surrounding the first resonance blind via form a first resonator, and the second resonance blind via and the dielectric body surrounding the second resonance blind via form a second resonator. A top surface of the dielectric body is provided with a first coupling through hole and a second coupling through hole, a first connection part is provided between the first coupling through hole and the second coupling through hole, and negative coupling is implemented between the first resonator and the second resonator via the first connection part. An on-board footprint of the dielectric filter can be reduced without reducing a single-cavity Q value of the resonator, thereby effectively implementing miniaturization of the dielectric filter. In addition, a remote suppression effect can be improved, and a loss of the dielectric filter can be reduced.

Description

[0001] This application claims priority to Chinese Patent Application No. 202310677885.8, filed with the China National Intellectual Property Administration on June 8, 2023 and entitled "DIELECTRIC FILTER AND COMMUNICATION APPARATUS", which is incorporated herein by reference in its entirety.

[0002] This application claims priority to Chinese Patent Application No. 202310912055.9, filed with the China National Intellectual Property Administration on July 21, 2023 and entitled "DIELECTRIC FILTER AND COMMUNICATION APPARATUS", which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0003] This application relates to the field of communication technologies, and in particular, to a dielectric filter and a communication apparatus.BACKGROUND

[0004] A dielectric filter is a filtering apparatus formed by coupling between dielectric resonators. Dielectric filters are widely used in communication apparatuses such as communication base stations, communication satellites, and navigation systems. The filter suppresses signals outside passband frequencies while allowing signals within the passband frequencies to pass through, thereby obtaining signals at specified frequencies and effectively eliminating interference signals.

[0005] In a related technology, a dielectric filter is provided. The dielectric filter includes a dielectric body. An upper surface of the dielectric body is provided with a plurality of resonance blind vias. Each resonance blind via and the dielectric body surrounding the resonance blind via may form a resonator of the filter. Signal energy conversion between electric and magnetic fields may be performed between two adjacent resonators, to implement coupling between the two resonators. Generally, a coupling blind via is further provided between two adjacent resonance blind vias, a via depth of the coupling blind via is greater than a depth of the resonance blind via, and the coupling blind via is used for implementing negative coupling between the two resonators.

[0006] However, a single-cavity Q value of the dielectric filter is in direct proportion to a projection size of the dielectric body in an axial direction of the resonance blind via. In the dielectric filter, the resonance blind via is located on the upper surface of the dielectric body, so that the dielectric filter occupies a large area (that is, an on-board footprint) on a mounting board. Reducing the on-board footprint of the dielectric filter lowers the single-cavity Q value of the dielectric filter and thus hampers miniaturization of the dielectric filter.SUMMARY

[0007] This application provides a dielectric filter and a communication apparatus, so that an on-board footprint of the dielectric filter can be reduced without reducing a single-cavity Q value of a resonator, thereby effectively implementing miniaturization of the dielectric filter.

[0008] A first aspect of this application provides a dielectric filter, including a dielectric body, where the dielectric body has a first side surface and a second side surface opposite to each other, and a top surface located between the first side surface and the second side surface.

[0009] The dielectric body is provided with at least one group of resonance blind vias, the at least one group of resonance blind vias includes a first group of resonance blind vias, and the first group of resonance blind vias includes a first resonance blind via and a second resonance blind via.

[0010] The first resonance blind via is located on the first side surface, and the second resonance blind via is located on the second side surface.

[0011] The first resonance blind via and the dielectric body surrounding the first resonance blind via form a first resonator, and the second resonance blind via and the dielectric body surrounding the second resonance blind via form a second resonator.

[0012] The top surface of the dielectric body is provided with a first coupling through hole and a second coupling through hole, a first connection part is provided between the first coupling through hole and the second coupling through hole, and negative coupling is implemented between the first resonator and the second resonator via the first connection part.

[0013] The first resonance blind via and the second resonance blind via are provided on the side surface of the dielectric body, and the top surface of the dielectric body is provided with the first coupling through hole and the second coupling through hole, to implement negative coupling between the first resonator and the second resonator. When a projection area of the dielectric body in a height direction (that is, a direction from an upper surface to a lower surface of the dielectric body) is reduced, a projection area of the dielectric body 110 in an axial direction of the resonance blind via (the first resonance blind via and the second resonance blind via) is not affected. In this way, an on-board footprint of the dielectric filter can be reduced by reducing the projection area of the dielectric body in the height direction, and the on-board footprint of the dielectric filter is reduced without reducing a single-cavity Q value of the resonator, thereby effectively implementing miniaturization of the dielectric filter.

[0014] In a possible implementation, the at least one group of resonance blind vias further includes a second group of resonance blind vias, and the second group of resonance blind vias includes a third resonance blind via and a fourth resonance blind via.

[0015] The third resonance blind via is located on the first side surface, and the fourth resonance blind via is located on the second side surface.

[0016] The third resonance blind via and the dielectric body surrounding the third resonance blind via form a third resonator, and the fourth resonance blind via and the dielectric body surrounding the fourth resonance blind via form a fourth resonator.

[0017] The top surface of the dielectric body is provided with a third coupling through hole, two second connection parts are provided on two sides of the third coupling through hole, and positive coupling is implemented between the third resonator and the fourth resonator by using the two second connection parts.

[0018] In a possible implementation, the top surface of the dielectric body is further provided with a first coupling slot, and both the first coupling through hole and the second coupling through hole are provided on a bottom wall of the first coupling slot.

[0019] The first coupling slot may adjust a size of a coupling channel between the first resonator and the second resonator, to change a coupling amount between the first resonator and the second resonator.

[0020] In a possible implementation, the top surface of the dielectric body is further provided with a second coupling slot, and the third coupling through hole is provided on a bottom wall of the second coupling slot.

[0021] The second coupling slot may adjust a size of a coupling channel between the third resonator and the fourth resonator, to change a coupling amount between the third resonator and the fourth resonator, so that more forms of coupling amounts can be implemented between the third resonator and the fourth resonator.

[0022] In a possible implementation, the top surface of the dielectric body is further provided with a third coupling slot, and the first coupling through hole, the second coupling through hole, and the third coupling through hole are all provided on a bottom wall of the third coupling slot.

[0023] In a possible implementation, the top surface of the dielectric body is further provided with a fourth coupling slot, and both the first coupling through hole and the third coupling through hole are provided on a bottom wall of the fourth coupling slot.

[0024] In a possible implementation, the dielectric body is further provided with a fourth coupling through hole.

[0025] The fourth coupling through hole is located on the first side surface or the second side surface of the dielectric body, and the fourth coupling through hole is located between two adjacent groups of resonance blind vias.

[0026] In a possible implementation, the top surface of the dielectric body is further provided with a fifth coupling slot. The fifth coupling slot penetrates from the first side surface to the second side surface of the dielectric body, and the fifth coupling slot is located between two adjacent groups of resonance blind vias.

[0027] The fifth coupling slot may also adjust a size of a coupling channel between the first resonator and the third resonator and a size of a coupling channel between the second resonator and the fourth resonator, so that coupling of different coupling amounts can be implemented between two adjacent resonators.

[0028] In a possible implementation, the top surface of the dielectric body is further provided with a fifth coupling through hole. The fifth coupling through hole is located between two adjacent groups of resonance blind vias.

[0029] The fifth coupling through hole may further adjust the size of the coupling channel between the first resonator and the third resonator and the size of the coupling channel between the second resonator and the fourth resonator, so that coupling of different coupling amounts can be implemented between two adjacent resonators.

[0030] In a possible implementation, there are a plurality of first groups of resonance blind vias and a plurality of second groups of resonance blind vias. The plurality of first groups of resonance blind vias and the plurality of second groups of resonance blind vias are arranged alternately.

[0031] In a possible implementation, the first resonance blind via and the second resonance blind via in the first group of resonance blind vias are coaxially provided.

[0032] The third resonance blind via and the fourth resonance blind via in the second group of resonance blind vias are coaxially provided.

[0033] In this way, normalization of an overall structure of the dielectric filter can be improved, facilitating design and production of the dielectric filter. In addition, when simulation calculation is performed on the dielectric filter, a size of each resonance blind via in the dielectric filter can be conveniently determined, thereby improving operation efficiency.

[0034] In a possible implementation, the dielectric filter further includes a conducting layer, and the conducting layer covers a surface of the dielectric body.

[0035] In a possible implementation, the dielectric filter further includes a signal input end.

[0036] The signal input end is signally connected to the first resonator.

[0037] In a possible implementation, the dielectric body is further provided with a first coupling blind via.

[0038] One end of the first coupling blind via is connected to the signal input end, and the other end of the first coupling blind via is connected to the first resonance blind via.

[0039] In a possible implementation, the dielectric body is further provided with a sixth coupling slot.

[0040] One end of the sixth coupling slot is connected to the other end of the first coupling blind via, and the other end of the sixth coupling slot is connected to the first resonance blind via.

[0041] In a possible implementation, the dielectric filter further includes a signal output end.

[0042] The signal input end is signally connected to the second resonator.

[0043] A second aspect of this application provides a communication apparatus, including the dielectric filter in any one of foregoing implementations.

[0044] In a possible implementation, the communication apparatus further includes an antenna, and the antenna is signally connected to the dielectric filter.BRIEF DESCRIPTION OF DRAWINGS

[0045] FIG. 1 is a diagram of a structure of a dielectric filter according to a related technology; FIG. 2 is a top view of a dielectric filter according to a related technology; FIG. 3 is a diagram of a structure of a dielectric filter from a perspective according to an embodiment of this application; FIG. 4 is a diagram of a structure of a dielectric filter from another perspective according to an embodiment of this application; FIG. 5 is a top view of a dielectric filter according to an embodiment of this application; FIG. 6 is a sectional view of a dielectric filter according to an embodiment of this application; FIG. 7 is a diagram of a structure of another dielectric filter according to an embodiment of this application; FIG. 8 is a top view of another dielectric filter according to an embodiment of this application; FIG. 9 is a diagram of a structure of disposing a signal input end according to an embodiment of this application; FIG. 10 is a diagram of signal echo efficiency of a dielectric filter in a related technology; and FIG. 11 is a diagram of signal echo efficiency of a dielectric filter according to an embodiment of this application. Reference numerals:

[0046] 100-Dielectric filter; 110-Dielectric body; 111-First side surface; 112-Second side surface; 120-First group of resonance blind vias; 121-First resonance blind via; 122-Second resonance blind via; 123-First resonator; 124-Second resonator; 130-Second group of resonance blind vias; 131-Third resonance blind via; 132-Fourth resonance blind via; 133-Third resonator; 134-Fourth resonator; 140-First coupling through hole; 141-Second coupling through hole; 142-First connection part; 143-Third coupling through hole; 144-Second connection part; 145-First coupling slot; 146-Second coupling slot; 147-Third coupling slot; 148-Fourth coupling slot; 149-Fourth coupling through hole; 150-Fifth coupling slot; 151-Fifth coupling through hole; 160-Signal input end; 161-First coupling blind via; and 162-Sixth coupling slot. DESCRIPTION OF EMBODIMENTS

[0047] Terms used in implementations of this application are merely used to explain specific embodiments of this application, but are not intended to limit this application.

[0048] A dielectric filter is a filtering apparatus formed by coupling between dielectric resonators. Dielectric filters are widely used in communication apparatuses such as communication base stations, communication satellites, and navigation systems. The filter may suppress signals outside passband frequencies while allowing signals within the passband frequencies to pass through, thereby obtaining signals at specified frequencies and effectively eliminating interference signals.

[0049] FIG. 1 is a diagram of a structure of a dielectric filter according to a related technology. FIG. 2 is a top view of a dielectric filter according to a related technology.

[0050] In the related technology, referring to FIG. 1 and FIG. 2, a dielectric filter 1 is provided. The dielectric filter 1 includes a dielectric body 11. An upper surface of the dielectric body 11 is provided with a plurality of resonance blind vias, for example, the plurality of resonance blind vias may include a first resonance blind via 12 and a second resonance blind via 13. Each resonance blind via and the dielectric body surrounding the resonance blind via may form a resonator of the dielectric filter. Signal energy conversion between electric and magnetic fields may be performed between two adjacent resonators, to implement coupling between the two resonators. A coupling blind via is further provided between two adjacent resonance blind vias. For example, as shown in FIG. 1 and FIG. 2, a first coupling blind via 14 (also referred to as a negative coupling deep hole) may be provided between the first resonance blind via 12 and the second resonance blind via 13, and a via depth of the first coupling blind via 14 is greater than a depth of the first resonance blind via 12 and a depth of the second resonance blind via 13. The first coupling blind via 14 is used for implementing negative coupling between a resonator including the first resonance blind via 12 and a resonator including the second resonance blind via 13.

[0051] Generally, a single-cavity Q value of the dielectric filter is in direct proportion to a projection size of the dielectric body in an axial direction of the resonance blind via, that is, a larger projection area of the dielectric body in the axial direction of the resonance blind via indicates a larger single-cavity Q value of the dielectric filter, and vice versa. The single-cavity Q value of the dielectric filter affects filtering efficiency of the dielectric filter, that is, a larger single-cavity Q value of the dielectric filter indicates a smaller filtering loss of the dielectric filter, and vice versa.

[0052] However, in the foregoing structure, the coupling blind via occupies an area of the upper surface of the dielectric body, so that the dielectric filter occupies a large area (that is, an on-board footprint) on a mounting board. This is not conducive to miniaturization of the dielectric filter. If the on-board footprint of the dielectric filter is reduced by reducing a size of the dielectric filter, the projection area of the dielectric body in the axial direction of the resonance blind via (for example, the first resonance blind via 12 and the second resonance blind via 13) is reduced accordingly, reducing the Q value of the resonator and increasing the loss of the dielectric filter.

[0053] In addition, the first coupling blind via 14 in the dielectric filter reduces a remote suppression capability of the dielectric filter, and reduces an out-of-band suppression effect of the dielectric filter. Therefore, in a process of using the dielectric filter, low-pass traces are generally required to suppress an out-of-band electromagnetic wave signal, and the low-pass traces have an insertion loss, which increases the loss of the dielectric filter.

[0054] To resolve the foregoing problem, researchers came up with the idea of improving the structure of the dielectric filter. The first resonance blind via and the second resonance blind via are provided on two side surfaces of the dielectric body, a top surface of the dielectric body is provided with a first coupling through hole and a second coupling through hole, a first connection part is provided between the first coupling through hole and the second coupling through hole, and negative coupling may be implemented between a first resonator and a second resonator by using the first connection part. When a projection area of the dielectric body in a height direction (that is, a direction from the upper surface to a lower surface of the dielectric body) is reduced, the projection area of the dielectric body 110 in the axial direction of the resonance blind via (the first resonance blind via and the second resonance blind via) is not affected. In this way, the on-board footprint of the dielectric filter can be reduced by reducing the projection area of the dielectric body in the height direction, and the on-board footprint of the dielectric filter is reduced without reducing the single-cavity Q value of the resonator, thereby effectively implementing miniaturization of the dielectric filter.

[0055] The following describes in detail the dielectric filter provided in embodiments of this application with reference to the accompanying drawings.

[0056] FIG. 3 is a diagram of a structure of a dielectric filter from a perspective according to an embodiment of this application. FIG. 4 is a diagram of a structure of a dielectric filter from another perspective according to an embodiment of this application. FIG. 5 is a top view of a dielectric filter according to an embodiment of this application. FIG. 6 is a sectional view of a dielectric filter according to an embodiment of this application.

[0057] This embodiment of this application provides a dielectric filter 100. Refer to FIG. 3 and FIG. 4. The dielectric filter 100 may include a dielectric body 110. For example, a material for forming the dielectric body 110 may be ceramic, and the dielectric body 110 may be integrally formed by using an injection molding process. In this way, stability and reliability of a structure of the dielectric body 110 can be improved. The dielectric body 110 has a first side surface 111 and a second side surface 112 that are opposite to each other, and a top surface 113 located between the first side surface 111 and the second side surface 112.

[0058] The dielectric body 110 may be provided with at least one group of resonance blind vias. For example, the at least one group of resonance blind vias may include a first group of resonance blind vias 120, and the first group of resonance blind vias 120 (as shown in FIG. 6) may include a first resonance blind via 121 and a second resonance blind via 122. The first resonance blind via 121 may be located on the first side surface 111, and the second resonance blind via 122 may be located on the second side surface 112. The first resonance blind via 121 and the dielectric body 110 surrounding the first resonance blind via 121 may form a first resonator 123, and the second resonance blind via 122 and the dielectric body 110 surrounding the second resonance blind via 122 may form a second resonator 124.

[0059] Refer to FIG. 5 and FIG. 6. The top surface 113 of the dielectric body 110 may be provided with a first coupling through hole 140 and a second coupling through hole 141. For example, the first coupling through hole 140 and the second coupling through hole 141 may penetrate from the top surface 113 of the dielectric body 110 to a bottom surface of the dielectric body 110. A first connection part 142 may be provided between the first coupling through hole 140 and the second coupling through hole 141, and negative coupling is implemented between the first resonator 123 and the second resonator 124.

[0060] For example, the first coupling through hole 140 and the second coupling through hole 141 may be located close to two sides of the first resonator 123 and the second resonator 124, so that the first connection part 142 can be located close to the middle of the first resonator 123 and the second resonator 124. Materials of the dielectric body 110 at corresponding positions may be removed for the first coupling through hole 140 and the second coupling through hole 141, and the first connection part 142 located between the first coupling through hole 140 and the second coupling through hole 141 is retained, so that the first resonator 123 and the second resonator 124 may be connected by using a material of the dielectric body 110 corresponding to the first connection part 142. An electromagnetic wave signal may be propagated from the first resonator 123 to the second resonator 124 by using the first connection part 142, to implement negative coupling between the first resonator 123 and the second resonator 124.

[0061] For example, the dielectric filter 100 may further include a conducting layer (not shown in the figure), and the conducting layer may cover a surface of the dielectric body 110. For example, the conducting layer may be disposed on the first side surface 111, the second side surface 112, the top surface 113, the bottom surface, an inner wall of the first resonance blind via 121, an inner wall of the second resonance blind via 122, an inner wall of the first coupling through hole 140, and an inner wall of the second coupling through hole 141 of the dielectric body 110. The dielectric filter 100 may be understood as a closed cavity formed by the conducting layer and filled with the dielectric body 110.

[0062] For example, after the dielectric body 110 is formed, a metal layer may be covered on the surface of the dielectric body 110 in a manner of spraying, painting, or the like, to form the conducting layer. For example, a material of the conducting layer may be silver.

[0063] In a working process, the electromagnetic wave signal may enter the dielectric filter 100 through a signal input port of the dielectric filter 100, and is propagated in the dielectric body 110. The electromagnetic wave signal is propagated from one resonator to another adjacent resonator. For example, the electromagnetic wave signal may be propagated from the first resonator 123 to the second resonator 124 by using the first connection part 142 between the first coupling through hole 140 and the second coupling through hole 141. There is an electric field close to a center of the resonator, and there is a magnetic field close to an edge of the resonator, that is, close to the conducting layer. Energy of the electric field and the magnetic field is continuously exchanged, so that the dielectric filter 100 generates electromagnetic resonance at some similar frequencies, and energy at the resonance may be transmitted from an input end to an output end of the dielectric filter 100. There is electric field coupling and magnetic field coupling between different resonators, so that a passband can be formed between the resonators. Only signals whose frequency are within the passband can pass through, and signals of other frequencies cannot pass through, thereby implementing a filtering effect.

[0064] When the electromagnetic wave signal encounters the conducting layer covered on the dielectric body 110, the electromagnetic wave signal may be reflected on the conducting layer. After the signal is repeatedly reflected in the dielectric filter 100, a part of signals may be totally reflected, and finally output from a signal output end of the dielectric filter 100, while another part of the signals cannot be totally reflected in the dielectric body 110, and is returned to a signal input end through an original path, so that the signals are filtered out.

[0065] In a process in which the electromagnetic wave signal is propagated from the first resonator 123 to the second resonator 124, negative coupling between the first resonator 123 and the second resonator 124 may be implemented. Negative coupling is also referred to as electrical coupling, and means that in a process in which the first resonator 123 is coupled to the second resonator 124, conversion from the electric field to the magnetic field is mainly used, that is, in a process in which the first resonator 123 is coupled to the second resonator 124 by using the first connection part 142, the electric field is mainly used. Negative coupling may generate a transmission zero (referring to a point A in FIG. 11), which can enhance a suppression effect and improve a suppression effect of the dielectric filter 100 on a signal at a frequency, so that the signal corresponding to the frequency is well suppressed. For example, in a process of using the dielectric filter 100, if a high suppression requirement needs to be imposed on a signal of a frequency, negative coupling may be provided in the dielectric filter 100, so that coupling of several resonators is negative coupling, thereby implementing strong suppression on the signal of the frequency.

[0066] A size of the first connection part 142 may affect a size of a coupling channel (also referred to as a window) between the first resonator 123 and the second resonator 124. A larger cross-sectional area of the first connection part 142 in a direction from the first resonator 123 to the second resonator 124 indicates a wider coupling channel between the first resonator 123 and the second resonator 124, and a larger signal frequency band that can pass through the coupling channel. In this case, a coupling amount between the first resonator 123 and the second resonator 124 is larger, and the larger coupling amount indicates a wider bandwidth.

[0067] On the contrary, a smaller cross-sectional area of the first connection part 142 in the direction from the first resonator 123 to the second resonator 124 indicates a narrower coupling channel between the first resonator 123 and the second resonator 124, and a smaller signal frequency band that can pass through the coupling channel. In this case, a coupling amount between the first resonator 123 and the second resonator 124 is smaller, and the smaller coupling amount indicates a narrower bandwidth.

[0068] Therefore, the size of the first connection part 142 may be changed by changing a size of the first coupling through hole 140, for example, changing a size of a cross-sectional area of the first coupling through hole 140 in the direction from the first resonator 123 to the second resonator 124, to change the coupling amount between the first resonator 123 and the second resonator 124.

[0069] In a process of installing the dielectric filter 100, a bottom surface of the dielectric filter 100 may be mounted on a mounting board, and an area occupied when the dielectric filter 100 is installed on the mounting board may be understood as an on-board footprint of the dielectric filter 100.

[0070] Compared with the related technology in which an upper surface of a dielectric body is provided with a resonance blind via and a coupling blind via to implement negative coupling between two resonators, in this embodiment of this application, the first resonance blind via 121 and the second resonance blind via 122 are provided on the side surfaces of the dielectric body 110, and the top surface 113 of the dielectric body 110 is provided with the first coupling through hole 140 and the second coupling through hole 141, to implement negative coupling between the first resonator 123 and the second resonator 124. When a projection area of the dielectric body 110 in a height direction (that is, a direction from an upper surface to a lower surface of the dielectric body) is reduced, a projection area of the dielectric body 110 in an axial direction of the resonance blind via (the first resonance blind via 121 and the second resonance blind via 122) is not affected. In this way, the on-board footprint of the dielectric filter 100 can be reduced by reducing the projection area of the dielectric body 110 in the height direction, and the on-board footprint of the dielectric filter 100 is reduced without reducing a single-cavity Q value of the resonator, thereby effectively implementing miniaturization of the dielectric filter 100.

[0071] In addition, compared with the resonance blind via of the dielectric filter in the related technology, the resonance blind vias (the first resonance blind via 121 and the second resonance blind via 122) of the dielectric filter 100 provided in this embodiment of this application are all provided on two side surfaces of the dielectric body 110. In this way, crosstalk between resonators can be reduced. Moreover, a design of a negative coupling deep hole (that is, the first coupling blind via 14 in FIG. 1) is removed. In this way, a remote suppression capability of the dielectric filter 100 can be effectively improved, and an out-of-band suppression effect can be effectively improved. Low-pass traces may not need to be disposed, and an insertion loss caused by excessive low-pass traces may be avoided, thereby effectively reducing a loss of the dielectric filter.

[0072] Still refer to FIG. 5 and FIG. 6. The dielectric body 110 may further include a second group of resonance blind vias 130, and the second group of resonance blind vias 130 may include a third resonance blind via 131 and a fourth resonance blind via 132. The third resonance blind via 131 and the dielectric body 110 surrounding the third resonance blind via 131 may form a third resonator 133, and the fourth resonance blind via 132 and the dielectric body 110 surrounding the fourth resonance blind via 132 may form a fourth resonator 134.

[0073] The top surface 113 of the dielectric body 110 may be further provided with a third coupling through hole 143, two second connection parts 144 are provided on two sides of the third coupling through hole 143, and positive coupling may be implemented between the third resonator 133 and the fourth resonator 134 by using the two second connection parts 144. Positive coupling is also referred to as magnetic coupling, and means that in a process in which the third resonator 133 is coupled to the fourth resonator 134, the magnetic field is mainly used.

[0074] For example, the third coupling through hole 143 may be provided close to a center of the third resonator 133 and the fourth resonator 134, so that a material of the dielectric body 110 at a center position between the third resonator 133 and the fourth resonator 134 is removed, and the dielectric body 110 between the third resonator 133 and the fourth resonator 134 is retained close to two sides, to form the two second connection parts 144. The third resonator 133 and the fourth resonator 134 may be connected by using materials of the dielectric body 110 corresponding to the two second connection parts 144. In this way, the electromagnetic wave signal may be propagated from the third resonator 133 to the fourth resonator 134 by using the two second connection parts 144 close to the two sides, to implement positive coupling between the third resonator 133 and the fourth resonator 134.

[0075] A size of the second connection part 144 may affect a size of a coupling channel (also referred to as a window) between the third resonator 133 and the fourth resonator 134. A larger cross-sectional area of the second connection part 144 in a direction from the third resonator 133 to the fourth resonator 134 indicates a wider coupling channel between the third resonator 133 and the fourth resonator 134. In this case, a coupling amount between the third resonator 133 and the fourth resonator 134 is larger.

[0076] On the contrary, a smaller cross-sectional area of the second connection part 144 in the direction from the third resonator 133 to the fourth resonator 134 indicates a narrower coupling channel between the third resonator 133 and the fourth resonator 134. In this case, a coupling amount between the third resonator 133 and the fourth resonator 134 is smaller. Therefore, the size of the second connection part 144 may be changed by changing a size of the third coupling through hole 143, for example, changing a size of a cross-sectional area of the third coupling through hole 143 in the direction from the third resonator 133 to the fourth resonator 134, to change the coupling amount between the third resonator 133 and the fourth resonator 134.

[0077] Still refer to FIG. 5. In a possible implementation, the dielectric body 110 may be further provided with a first coupling slot 145, and both the first coupling through hole 140 and the second coupling through hole 141 may be provided on a bottom wall of the first coupling slot 145. A material of the dielectric body 110 at a position of the first connection part 142 close to the top surface 113 of the dielectric body 110 may be removed for the first coupling slot 145, to further reduce the size of the first connection part 142, and adjust the size of the coupling channel between the first resonator 123 and the second resonator 124, to change the coupling amount between the first resonator 123 and the second resonator 124.

[0078] For example, when a size of the first coupling slot 145 in a direction from the top surface 113 to the bottom surface of the dielectric body 110 is large, that is, a depth of the first coupling slot 145 is deep, a cross-sectional area of the first coupling slot 145 in the direction from the third resonator 133 to the fourth resonator 134 is also large, so that the cross-sectional area of the first connection part 142 in the direction from the first resonator 123 to the second resonator 124 is small, and the coupling amount between the first resonator 123 and the second resonator 124 can be reduced.

[0079] On the contrary, when the size of the first coupling slot 145 in the direction from the top surface 113 to the bottom surface of the dielectric body 110 is small, that is, the depth of the first coupling slot 145 is shallow, the cross-sectional area of the first coupling slot 145 in the direction from the first resonator 123 to the second resonator 124 is also small, so that the cross-sectional area of the first connection part 142 in the direction from the first resonator 123 to the second resonator 124 is large, and the coupling amount between the first resonator 123 and the first resonator 123 can be increased.

[0080] Still refer to FIG. 5. In another possible implementation, the top surface 113 of the dielectric body 110 may be further provided with a second coupling slot 146, and the third coupling through hole 143 may be provided on a bottom wall of the second coupling slot 146. A material of the dielectric body 110 at a position of the second connection part 144 close to the top surface 113 of the dielectric body 110 may be removed for the second coupling slot 146, to further reduce the size of the second connection part 144, and adjust the size of the coupling channel between the third resonator 133 and the fourth resonator 134, to change the coupling amount between the third resonator 133 and the fourth resonator 134, so that more forms of coupling amounts can be implemented between the third resonator 133 and the fourth resonator 134.

[0081] For example, when a size of the second coupling slot 146 in the direction from the top surface 113 to the bottom surface of the dielectric body 110 is large, that is, a depth of the second coupling slot 146 is deep, a cross-sectional area of the second coupling slot 146 in the direction from the third resonator 133 to the fourth resonator 134 is also large, so that the cross-sectional area of the second connection part 144 in the direction from the third resonator 133 to the fourth resonator 134 is small, and the coupling amount between the third resonator 133 and the fourth resonator 134 can be reduced.

[0082] On the contrary, when the size of the second coupling slot 146 in the direction from the top surface 113 to the bottom surface of the dielectric body 110 is small, that is, the depth of the second coupling slot 146 is shallow, the cross-sectional area of the second coupling slot 146 in the direction from the third resonator 133 to the fourth resonator 134 is also small, so that the cross-sectional area of the second connection part 144 in the direction from the third resonator 133 to the fourth resonator 134 is large, and the coupling amount between the third resonator 133 and the fourth resonator 134 can be increased.

[0083] Alternatively, in still another possible implementation, still referring to FIG. 5 and FIG. 6, the top surface 113 of the dielectric body 110 may be further provided with a third coupling slot 147, and the first coupling through hole 140, the second coupling through hole 141, and the third coupling through hole 143 may all be provided on a bottom wall of the third coupling slot 147. In this case, it may also be understood as that the first coupling slot 145 is connected to the second coupling slot 146. For example, the third coupling slot 147 may penetrate from one end to the other end of the dielectric body 110, and then the first coupling through hole 140, the second coupling through hole 141, and the third coupling through hole 143 are separately provided on the bottom wall of the third coupling slot 147.

[0084] Still refer to FIG. 5 and FIG. 6. In some examples, the top surface 113 of the dielectric body may be further provided with a fifth coupling through hole 151, and the fifth coupling through hole 151 may be located between two adjacent groups of resonance blind vias. For example, in this embodiment of this application, the fifth coupling through hole 151 may be provided between the first group of resonance blind vias 120 and the second group of resonance blind vias 130 that are adjacent to each other. The fifth coupling through hole 151 may further adjust a size of a coupling channel between the first resonator 123 and the third resonator 133 and a size of a coupling channel between the second resonator 124 and the fourth resonator 134, so that coupling of different coupling amounts can be implemented between two adjacent resonators.

[0085] Coupling between the first resonator 123 and the third resonator 133 is used as an example. The fifth coupling through hole 151 may be a long through hole shown in FIG. 5. In this case, a cross-sectional area of the fifth coupling through hole 151 in a direction from the first resonator 123 to the third resonator 133 is large, so that the coupling channel between the first resonator 123 and the third resonator 133 can be small, and a coupling amount between the first resonator 123 and the third resonator 133 can be further reduced.

[0086] Alternatively, the fifth coupling through hole 151 may be a cylindrical through hole. In this case, a cross-sectional area of the fifth coupling through hole 151 in a direction from the first resonator 123 to the third resonator 133 is small, so that the coupling channel between the first resonator 123 and the third resonator 133 can be large, and a large coupling amount can be implemented between the first resonator 123 and the third resonator 133.

[0087] In this embodiment of this application, there may be a plurality of first groups of resonance blind vias 120 and a plurality of second groups of resonance blind vias 130, and the plurality of first groups of resonance blind vias 120 and the plurality of second groups of resonance blind vias 130 may be arranged alternately. For example, as shown in FIG. 6, there may be two first groups of resonance blind vias 120, and there may be three second groups of resonance blind vias 130, where one first group of resonance blind vias 120 may exist between every two second groups of resonance blind vias 130.

[0088] Arrangement of the first group of resonance blind vias 120 and the second group of resonance blind vias 130 may affect a filtering result of the dielectric filter 100. For example, when the first group of resonance blind vias 120 and the second group of resonance blind vias 130 may be arranged alternately, the dielectric filter 100 may obtain a signal of a frequency band, and filter out another signal outside the frequency band. When the first group of resonance blind vias 120 and the second group of resonance blind vias 130 are arranged in another manner, for example, the dielectric filter 100 may obtain a signal of another frequency band, and filter out a signal outside the frequency band.

[0089] For example, in some examples, alternatively, the plurality of first groups of resonance blind vias 120 may be arranged adjacently in sequence, and then the plurality of second groups of resonance blind vias 130 are arranged in sequence. Specifically, the arrangement of the first group of resonance blind vias 120 and the second group of resonance blind vias 130 may be selected and set based on a filtering requirement of the dielectric filter 100. In this embodiment of this application, an example in which the first group of resonance blind vias 120 and the second group of resonance blind vias 130 are arranged alternately is used for description.

[0090] FIG. 7 is a diagram of a structure of another dielectric filter according to an embodiment of this application. FIG. 8 is a top view of another dielectric filter according to an embodiment of this application.

[0091] Alternatively, in some examples, referring to FIG. 7 and FIG. 8, a top surface 113 of a dielectric body 110 may be further provided with a fourth coupling slot 148, and a first coupling through hole 140 and a third coupling through hole 143 may be provided on a bottom wall of the fourth coupling slot 148. For example, a first group of resonators (that is, resonators including a first group of resonance blind vias 120) and a second group of resonators (that is, resonators including a second group of resonance blind vias 130) may be disposed adjacently. In this case, the top surface 113 of the dielectric body 110 may be provided with the fourth coupling slot 148, and the fourth coupling slot 148 may extend from the first group of resonators to a position at which the first coupling through hole 140 is provided in the second group of resonators, and then the first coupling through hole 140 and the third coupling through hole 143 are provided on the bottom wall of the fourth coupling slot 148.

[0092] Still refer to FIG. 7 and FIG. 8. The dielectric body 110 may be further provided with a fourth coupling through hole 149, the fourth coupling through hole 149 may be located on a first side surface 111 or a second side surface 112 of the dielectric body 110, and the fourth coupling through hole 149 may be located between two adjacent groups of resonance blind vias.

[0093] For example, in this embodiment of this application, the fourth coupling through hole 149 may be provided between the first group of resonance blind vias 120 and the second group of resonance blind vias 130 that are adjacent to each other. Resonators including two adjacent resonance blind vias that are located on a same side surface may also be coupled. For example, a first resonator 123 including a first resonance blind via 121 and a third resonator 133 including a third resonance blind via 131 may also be coupled. Correspondingly, a second resonator 124 and a fourth resonator 134 may also be coupled. The fourth coupling through hole 149 may adjust a size of a coupling channel between the first resonator 123 and the third resonator 133 or a size of a coupling channel between the second resonator 124 and the fourth resonator 134.

[0094] For example, when the fourth coupling through hole 149 is located on the first side surface 111 of the dielectric body 110, the fourth coupling through hole 149 may adjust the size of the coupling channel between the first resonator 123 and the third resonator 133. When the fourth coupling through hole 149 is located on the second side surface 112 of the dielectric body 110, the fourth coupling through hole 149 may adjust the size of the coupling channel between the second resonator 124 and the fourth resonator 134.

[0095] Coupling between the first resonator 123 and the third resonator 133 is used as an example. The fourth coupling through hole 149 may be a cylindrical through hole, and a cross-sectional area of the fourth coupling through hole 149 in a direction from the first resonator 123 to the third resonator 133 is small. In this case, the coupling channel between the first resonator 123 and the third resonator 133 is large, so that a large coupling amount can be implemented between the first resonator 123 and the third resonator 133. Alternatively, the fourth coupling through hole 149 may be a long through hole, and a cross-sectional area of the fourth coupling through hole 149 in a direction from the first resonator 123 to the third resonator 133 is large. In this case, the coupling channel between the first resonator 123 and the third resonator 133 is small, so that a small coupling amount can be implemented between the first resonator 123 and the third resonator 133.

[0096] In a specific application process, a shape and a size of the cross-sectional area of the fourth coupling through hole 149 may be designed based on a requirement for the coupling amount between the first resonator 123 and the third resonator 133.

[0097] Correspondingly, the fourth coupling through hole 149 also has a same function for controlling a coupling amount between the second resonator 124 and the fourth resonator 134. Details are not described herein again.

[0098] The fourth coupling through hole 149 located on the first side surface 111 and the fourth coupling through hole 149 located on the second side surface 112 may be coaxially provided, or the fourth coupling through hole 149 located on the first side surface 111 and the fourth coupling through hole 149 located on the second side surface 112 may be staggered. Specifically, setting positions of the fourth coupling through hole 149 located on the first side surface 111 and the fourth coupling through hole 149 located on the second side surface 112 may be selected and set based on a specific application requirement.

[0099] Alternatively, in some examples, the top surface 113 of the dielectric body 110 may be further provided with a fifth coupling slot 150 (referring to FIG. 3 and FIG. 4), the fifth coupling slot 150 may penetrate from the first side surface 111 to the second side surface 112 of the dielectric body 110, and the fifth coupling slot 150 may be located between two adjacent groups of resonance blind vias. For example, in this embodiment of this application, the fifth coupling slot 150 may be provided between the first group of resonance blind vias 120 and the second group of resonance blind vias 130 that are adjacent to each other. The fifth coupling slot 150 may also adjust the size of the coupling channel between the first resonator 123 and the third resonator 133 and the size of the coupling channel between the second resonator 124 and the fourth resonator 134, so that coupling of different coupling amounts can be implemented between two adjacent resonators.

[0100] The coupling between the first resonator 123 and the third resonator 133 is still used as an example. A deeper depth of the fifth coupling slot 150 indicates a larger cross-sectional area of the fifth coupling slot 150 in the direction from the first resonator 123 to the third resonator 133, a narrower coupling channel between the first resonator 123 and the third resonator 133, and a smaller coupling amount between the first resonator 123 and the third resonator 133. On the contrary, a shallower depth of the fifth coupling slot 150 indicates a smaller cross-sectional area of the fifth coupling slot 150 in the direction from the first resonator 123 to the third resonator 133, a wider coupling channel between the first resonator 123 and the third resonator 133, and a smaller coupling amount between the first resonator 123 and the third resonator 133. In a specific application process, a depth size of the fifth coupling slot 150 may be designed based on a requirement for the coupling amount between the first resonator 123 and the third resonator 133.

[0101] In this embodiment of this application, the first resonance blind via 121 and the second resonance blind via 122 in the first group of resonance blind vias 120 may be coaxially provided, and the third resonance blind via 131 and the fourth resonance blind via 132 in the second group of resonance blind vias 130 may also be coaxially provided. In this way, normalization of an overall structure of the dielectric filter 100 can be improved, facilitating design and production of the dielectric filter 100. In addition, when simulation calculation is performed on the dielectric filter 100, a size of each resonance blind via in the dielectric filter 100 can be conveniently determined, thereby improving operation efficiency.

[0102] FIG. 9 is a diagram of a structure of disposing a signal input end according to an embodiment of this application.

[0103] In this embodiment of this application, referring to FIG. 9, the dielectric filter 100 may further include a signal input end 160, and the signal input end 160 may be signally connected to the first resonator 123. An electromagnetic wave signal may be input from the signal input end 160 and enter the dielectric filter 100 through the first resonator 123.

[0104] For example, as shown in FIG. 9, the dielectric body 110 may be further provided with a first coupling blind via 161. One end of the first coupling blind via 161 may be connected to the signal input end 160, and the other end of the first coupling blind via 161 may be connected to the first resonance blind via 121. The signal input end 160 may perform coupled feeding on the first resonator 123 through the first coupling blind via 161, so that the electromagnetic wave signal can be fed into the dielectric filter 100.

[0105] Certainly, in some examples, the signal input end 160 may alternatively be signally connected to the second resonator 124, the third resonator 133, or the fourth resonator 134, to implement input of an electromagnetic wave signal.

[0106] Still refer to FIG. 9. The dielectric body 110 may be further provided with a sixth coupling slot 162. One end of the sixth coupling slot 162 may be connected to the other end of the first coupling blind via 161, and the other end of the sixth coupling slot 162 may be connected to the first resonance blind via 121. The signal input end 160 may perform coupled feeding on the first resonator 123 through the first coupling blind via 161 and the sixth coupling slot 162 in sequence, to implement signal input.

[0107] Correspondingly, the dielectric filter 100 may further include a signal output end (not shown in the figure). The signal output end may be signally connected to the second resonator 124. After being fed into the dielectric filter 100 from the signal input end 160, an electromagnetic wave signal may be repeatedly reflected in the dielectric body 110, and finally output from the signal output end, to complete a filtering function of the dielectric filter 100.

[0108] For setting of the signal connection between the signal output end and the second resonator, refer to the connection between the signal input end 160 and the first resonator 123. Details are not described herein again.

[0109] Alternatively, in some examples, the signal output end may be signally connected to the second resonator 124, the third resonator 133, or the fourth resonator 134, to implement output of an electromagnetic wave signal.

[0110] An embodiment of this application further provides a communication apparatus. The communication apparatus may include the dielectric filter 100 in any one of the foregoing examples. For example, the communication apparatus may be a communication base station, satellite communication, or a navigation system. The dielectric filter 100 may filter out an interference signal in the communication apparatus, to improve signal stability and reliability during operation of the communication apparatus.

[0111] The communication apparatus includes the foregoing dielectric filter 100, so that installation space occupied by the dielectric filter 100 in the communication apparatus can be effectively reduced, thereby improving rationality and normalization of a layout of internal components of the communication apparatus.

[0112] For example, the communication apparatus may further include an antenna, and the antenna may be signally connected to the dielectric filter 100. The antenna may be configured to transmit and receive a signal. The dielectric filter 100 is configured to filter a signal received by the antenna, or send a filtered signal to the antenna.

[0113] The following performs a simulation test on the dielectric filter 100 provided in this embodiment of this application with reference to the accompanying drawings.

[0114] FIG. 10 is a diagram of signal echo efficiency of a dielectric filter in a related technology. FIG. 11 is a diagram of signal echo efficiency of a dielectric filter according to an embodiment of this application.

[0115] Refer to FIG. 10. A horizontal coordinate in the figure indicates a frequency, and a vertical coordinate indicates a signal power. A value of a vertical coordinate of a curve in the figure being farther from a value 0 indicates fewer signals from an input end to an output end, that is, signals of the frequency are filtered out by the dielectric filter 100 and are not output from the signal output end. On the contrary, the value of the vertical coordinate of the curve in the figure being closer to the value 0 indicates more signals from the input end to the output end. It indicates that signals of the frequency pass through the dielectric filter 100 and are output from the output end of the dielectric filter 100.

[0116] Therefore, it can be learned from FIG. 10 that the dielectric filter 100 in the related technology has a resonance point at a frequency band with a center frequency of 3.5 GHz, and a signal within the frequency band passes through the dielectric filter 100. In addition, it can be further learned from FIG. 10 that two low-frequency resonance points appear around a frequency of 2.5 GHz, at which signal echoes are small, and some energy passes through the dielectric filter 100. It indicates that a signal suppression effect of the dielectric filter 100 at the frequency is poor.

[0117] In addition, in a frequency band of 6.0 GHz to 6.5 GHz, a high-order mode resonance occurs in the dielectric filter 100, that is, an out-of-band resonance mode exists. The out-of-band resonance mode means that the dielectric filter 100 resonates outside a passband. The high-order mode resonance refers to an out-of-band resonance mode in which a resonance frequency is about twice or multiple times a passband frequency, and a parasitic passband is generated at a frequency about twice or multiple times the passband frequency, causing deterioration of a suppression effect of the filter at a frequency about twice or multiple times the passband frequency. Therefore, it can be learned from the figure that the dielectric filter 100 in the related technology has a poor suppression effect on a high-order mode signal.

[0118] Generally, in the related technology, to resolve a problem of the high-order mode resonance, in a process of using the dielectric filter 100, a low-pass trace stub line needs to be added to the dielectric filter 100 to suppress the high-order mode signal, and an insertion loss is large, which increases a loss of the dielectric filter. In addition, an overall layout area and costs of the dielectric filter are occupied.

[0119] FIG. 11 is a diagram of signal echo efficiency of a dielectric filter 100 according to an embodiment of this application. It can be learned from FIG. 11 that there is a resonance point at a frequency band with a center frequency of 3.5 GHz, and a signal within the frequency band passes through the dielectric filter 100. In addition, the low-frequency resonance and the high-order mode resonance that occur in FIG. 10 do not occur. In this way, in a process of using the dielectric filter 100, a low-pass trace stub does not need to be disposed, so that an insertion loss problem caused by an increase of low-pass traces can be avoided, thereby effectively reducing a loss and costs of the dielectric filter 100.

[0120] In descriptions of embodiments of this application, it should be noted that, unless otherwise clearly specified and limited, the term "installation", "interconnection", or "connection" should be understood in a broad sense, for example, may be fastening, may be an indirect connection through an intermediate medium, or may be an internal connection between two elements or an interaction relationship between two elements. A person of ordinary skill in the art may understand specific meanings of the foregoing terms in embodiments of this application based on specific cases. The terms "first", "second", "third", "fourth", and the like (if any) are intended to distinguish between similar objects but do not necessarily indicate a specific order or sequence.

[0121] Finally, it should be noted that the foregoing embodiments are merely used to describe the technical solutions in embodiments of this application, but not to limit the technical solutions. Although embodiments of this application are described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that the technical solutions recorded in the foregoing embodiments may still be modified, or some or all of technical features thereof may be equivalently replaced. However, these modifications or replacements do not depart from the scope of the technical solutions in embodiments of this application.

Claims

1. A dielectric filter, comprising a dielectric body, wherein the dielectric body has a first side surface and a second side surface opposite to each other, and a top surface located between the first side surface and the second side surface; the dielectric body is provided with at least one group of resonance blind vias, the at least one group of resonance blind vias comprises a first group of resonance blind vias, and the first group of resonance blind vias comprises a first resonance blind via and a second resonance blind via; the first resonance blind via is located on the first side surface, and the second resonance blind via is located on the second side surface; the first resonance blind via and the dielectric body surrounding the first resonance blind via form a first resonator, and the second resonance blind via and the dielectric body surrounding the second resonance blind via form a second resonator; and the top surface of the dielectric body is provided with a first coupling through hole and a second coupling through hole, a first connection part is provided between the first coupling through hole and the second coupling through hole, and negative coupling is implemented between the first resonator and the second resonator via the first connection part.

2. The dielectric filter according to claim 1, wherein the at least one group of resonance blind vias further comprises a second group of resonance blind vias, and the second group of resonance blind vias comprises a third resonance blind via and a fourth resonance blind via; the third resonance blind via is located on the first side surface, and the fourth resonance blind via is located on the second side surface; the third resonance blind via and the dielectric body surrounding the third resonance blind via form a third resonator, and the fourth resonance blind via and the dielectric body surrounding the fourth resonance blind via form a fourth resonator; and the top surface of the dielectric body is provided with a third coupling through hole, two second connection parts are provided on two sides of the third coupling through hole, and positive coupling is implemented between the third resonator and the fourth resonator by using the two second connection parts.

3. The dielectric filter according to claim 2, wherein the top surface of the dielectric body is further provided with a first coupling slot, and both the first coupling through hole and the second coupling through hole are provided on a bottom wall of the first coupling slot.

4. The dielectric filter according to claim 2 or 3, wherein the top surface of the dielectric body is further provided with a second coupling slot, and the third coupling through hole is provided on a bottom wall of the second coupling slot.

5. The dielectric filter according to any one of claims 2 to 4, wherein the top surface of the dielectric body is further provided with a third coupling slot, and the first coupling through hole, the second coupling through hole, and the third coupling through hole are all provided on a bottom wall of the third coupling slot.

6. The dielectric filter according to any one of claims 2 to 5, wherein the top surface of the dielectric body is further provided with a fourth coupling slot, and both the first coupling through hole and the third coupling through hole are provided on a bottom wall of the fourth coupling slot.

7. The dielectric filter according to any one of claims 2 to 6, wherein the dielectric body is further provided with a fourth coupling through hole; and the fourth coupling through hole is located on the first side surface or the second side surface of the dielectric body, and the fourth coupling through hole is located between two adjacent groups of resonance blind vias.

8. The dielectric filter according to any one of claims 2 to 6, wherein the top surface of the dielectric body is further provided with a fifth coupling slot; and the fifth coupling slot penetrates from the first side surface to the second side surface of the dielectric body, and the fifth coupling slot is located between two adjacent groups of resonance blind vias.

9. The dielectric filter according to any one of claims 2 to 6, wherein the top surface of the dielectric body is further provided with a fifth coupling through hole; and the fifth coupling through hole is located between two adjacent groups of resonance blind vias.

10. The dielectric filter according to any one of claims 2 to 9, wherein there are a plurality of first groups of resonance blind vias and a plurality of second groups of resonance blind vias; and the plurality of first groups of resonance blind vias and the plurality of second groups of resonance blind vias are arranged alternately.

11. The dielectric filter according to any one of claims 2 to 10, wherein the first resonance blind via and the second resonance blind via in the first group of resonance blind vias are coaxially provided; and the third resonance blind via and the fourth resonance blind via in the second group of resonance blind vias are coaxially provided.

12. The dielectric filter according to any one of claims 1 to 11, wherein the dielectric filter further comprises a conducting layer, and the conducting layer covers a surface of the dielectric body.

13. The dielectric filter according to any one of claims 1 to 12, wherein the dielectric filter further comprises a signal input end; and the signal input end is signally connected to the first resonator.

14. The dielectric filter according to claim 13, wherein the dielectric body is further provided with a first coupling blind via; and one end of the first coupling blind via is connected to the signal input end, and the other end of the first coupling blind via is connected to the first resonance blind via.

15. The dielectric filter according to claim 14, wherein the dielectric body is further provided with a sixth coupling slot; and one end of the sixth coupling slot is connected to the other end of the first coupling blind via, and the other end of the sixth coupling slot is connected to the first resonance blind via.

16. The dielectric filter according to any one of claims 1 to 15, wherein the dielectric filter further comprises a signal output end; and the signal input end is signally connected to the second resonator.

17. A communication apparatus, comprising the dielectric filter according to any one of claims 1 to 16.

18. The communication apparatus according to claim 17, wherein the communication apparatus further comprises an antenna, and the antenna is signally connected to the dielectric filter.

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