Dielectric filters and communication devices
By positioning resonant blind vias on the side surfaces and using top-surface coupling through-holes, the dielectric filter's footprint is reduced while maintaining high Q-factor and suppression capabilities, addressing the challenges of miniaturization and loss in existing designs.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- HUAWEI TECH CO LTD
- Filing Date
- 2024-06-03
- Publication Date
- 2026-06-29
AI Technical Summary
Dielectric filters occupy a large area on the mounting substrate due to the positioning of resonant blind vias on the top surface, which reduces the single-cavity Q-factor and hinders miniaturization, while also increasing losses and diminishing out-of-band suppression.
The resonant blind vias are positioned on the side surfaces of the dielectric, with coupling through-holes on the top surface to achieve negative and positive coupling between resonators, reducing the height-direction footprint without affecting the axial Q-factor, and eliminating the need for low-pass traces.
This configuration minimizes the dielectric filter's footprint, enhances suppression capabilities, reduces losses, and maintains high Q-factor, enabling effective miniaturization without compromising performance.
Smart Images
Figure 2026521241000001_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of communication technologies, and particularly to dielectric filters and communication devices.
Background Art
[0002] This application was filed with the China National Intellectual Property Administration on June 8, 2023, and claims priority based on Chinese Patent Application No. 202310677885.8 entitled "Dielectric Filter and Communication Device", the entire content of which is incorporated herein by reference.
[0003] This application was filed with the China National Intellectual Property Administration on July 21, 2023, and claims priority based on Chinese Patent Application No. 202310912055.9 entitled "Dielectric Filter and Communication Device", the entire content of which is incorporated herein by reference.
[0004] A dielectric filter is a filter device formed by the coupling between dielectric resonators. Dielectric filters are widely used in communication devices such as communication base stations, communication satellites, and navigation systems. The filter allows signals within the passband frequency to pass through while suppressing signals outside the passband frequency, thereby obtaining signals of a predetermined frequency and effectively removing interference signals.
[0005] In related technologies, a dielectric filter is provided. The dielectric filter includes a dielectric. On the upper surface of the dielectric, a plurality of resonant blind vias are provided. Each resonant blind via and the dielectric surrounding the resonant blind via can form a resonator of the filter. Between two adjacent resonators, signal energy conversion between the electric field and the magnetic field may be performed to achieve the coupling between the two resonators. Generally, a coupling blind via is further provided between two adjacent resonant blind vias, the via depth of the coupling blind via is greater than the depth of the resonant blind via, and the coupling blind via is used to achieve negative coupling between two resonators.
[0006] However, the single-cavity Q-factor of a dielectric filter is directly proportional to the projected size of the dielectric in the axial direction of the resonant blind via. In dielectric filters, the resonant blind via is positioned on the top surface of the dielectric so that the dielectric filter occupies a large area (i.e., on-board footprint) on the mounting substrate. Reducing the on-board footprint of the dielectric filter lowers the single-cavity Q-factor of the dielectric filter, which in turn hinders the miniaturization of the dielectric filter. [Overview of the Initiative]
[0007] This application provides a dielectric filter and a communication device that can reduce the onboard footprint of the dielectric filter without lowering the single cavity Q value of the resonator, thereby effectively achieving miniaturization of the dielectric filter.
[0008] A first aspect of this application provides a dielectric filter, the dielectric filter comprising a dielectric having a first side surface and a second side surface facing each other, and a top surface located between the first side surface and the second side surface.
[0009] The dielectric is provided with at least one group of resonant blind vias, the at least one group of resonant blind vias including a first group of resonant blind vias, the first group of resonant blind vias including a first resonant blind via and a second resonant blind via.
[0010] The first resonant blind via is located on the first side, and the second resonant blind via is located on the second side.
[0011] The first resonant blind via and the dielectric surrounding the first resonant blind via form a first resonator, and the second resonant blind via and the dielectric surrounding the second resonant blind via form a second resonator.
[0012] A first coupling through-hole and a second coupling through-hole are provided on the upper surface of the dielectric, and a first connection is provided between the first coupling through-hole and the second coupling through-hole, thereby realizing a negative coupling between the first resonator and the second resonator via the first connection.
[0013] The first and second resonant blind vias are provided on the side surface of the dielectric, and the first and second coupling through-holes are provided on the top surface of the dielectric so as to achieve negative coupling between the first and second resonators. Reducing the projected area of the dielectric in the height direction (i.e., from the top surface to the bottom surface of the dielectric) does not affect the projected area of the dielectric 110 in the axial direction of the resonant blind vias (first and second resonant blind vias). In this way, by reducing the projected area of the dielectric in the height direction, the onboard footprint of the dielectric filter can be reduced, and the onboard footprint of the dielectric filter can be reduced without lowering the single cavity Q value of the resonator, thereby effectively achieving miniaturization of the dielectric filter.
[0014] In a possible implementation, at least one group of resonant blind vias further comprises a second group of resonant blind vias, the second group of resonant blind vias comprising a third group of resonant blind vias and a fourth group of resonant blind vias.
[0015] The third resonant blind via is located on the first side, and the fourth resonant blind via is located on the second side.
[0016] The third resonant blind via and the dielectric surrounding the third resonant blind via form a third resonator, and the fourth resonant blind via and the dielectric surrounding the fourth resonant blind via form a fourth resonator.
[0017] A third coupling through-hole is provided on the upper surface of the dielectric, and two second connection points are provided on both sides of the third coupling through-hole. By using the two second connection points, a positive coupling is achieved between the third resonator and the fourth resonator.
[0018] In possible implementations, a first coupling slot is further provided on the upper surface of the dielectric, and both the first and second coupling through-holes are located in the bottom wall of the first coupling slot.
[0019] The first coupling slot may adjust the size of the coupling channel between the first and second resonators in order to change the amount of coupling between the first and second resonators.
[0020] In possible implementations, a second coupling slot is provided on the upper surface of the dielectric, and a third coupling through-hole is provided in the bottom wall of the second coupling slot.
[0021] The second coupling slot may adjust the size of the coupling channel between the third and fourth resonators to change the amount of coupling between the third and fourth resonators, thereby enabling a wider variety of coupling configurations between the third and fourth resonators.
[0022] In possible implementations, a third coupling slot is provided on the upper surface of the dielectric, and all of the first, second, and third coupling through-holes are located in the bottom wall of the third coupling slot.
[0023] In possible implementations, a fourth coupling slot is further provided on the upper surface of the dielectric, and both the first and third coupling through-holes are located in the bottom wall of the fourth coupling slot.
[0024] In possible implementations, the dielectric material 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, and the fourth coupling through-hole is located between two adjacent resonance blind via groups.
[0026] In a possible implementation, a fifth coupling slot is further provided on the upper surface of the dielectric. The fifth coupling slot penetrates from the first side surface to the second side surface of the dielectric, and the fifth coupling slot is located between two adjacent resonance blind via groups.
[0027] The fifth coupling slot may also 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 as to achieve couplings with different coupling amounts between two adjacent resonators.
[0028] In a possible implementation, a fifth coupling through-hole is further provided on the upper surface of the dielectric. The fifth coupling through-hole is located between two adjacent resonance blind via groups.
[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 as to achieve couplings with different coupling amounts between two adjacent resonators.
[0030] In a possible implementation, there are a plurality of first resonance blind via groups and a plurality of second resonance blind via groups, and the plurality of first resonance blind via groups and the plurality of second resonance blind via groups are arranged alternately.
[0031] In a possible implementation, the first resonance blind via and the second resonance blind via in the first resonance blind via group are provided coaxially.
[0032] The third resonance blind via and the fourth resonance blind via in the second resonance blind via group are provided coaxially.
[0033] In this way, the normalization of the overall structure of dielectric filters can be improved, making the design and manufacture of dielectric filters easier. Furthermore, when performing simulation calculations on dielectric filters, the size of each resonant blind via in the dielectric filter can be easily determined, thereby improving work efficiency.
[0034] In possible implementations, the dielectric filter further includes a conductive layer, which covers the surface of the dielectric.
[0035] In possible implementations, the dielectric filter further includes a signal input terminal.
[0036] The signal input terminal is signal-connected (signally connected) to the first resonator.
[0037] In possible implementations, the dielectric is further provided with a first coupled blind via.
[0038] One end of the first coupled blind via is connected to the signal input terminal, and the other end of the first coupled blind via is connected to the first resonant blind via.
[0039] In possible implementations, the dielectric material 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 resonant blind via.
[0041] In possible implementations, the dielectric filter further includes a signal output terminal.
[0042] The signal input terminal is signal-connected to the second resonator.
[0043] A second aspect of this application provides a communication device, the communication device including a dielectric filter in any one of the above-described implementations.
[0044] In possible implementations, the communication device further includes an antenna, which is signal-connected to a dielectric filter. [Brief explanation of the drawing]
[0045] [Figure 1] This is a diagram showing the structure of a dielectric filter related to the technology. [Figure 2] This is a top view of the structure of a dielectric filter related to the technology. [Figure 3] This is a diagram showing the structure of a dielectric filter according to an embodiment of this application, viewed from one viewpoint. [Figure 4] This is a diagram showing the structure of a dielectric filter according to an embodiment of this application, viewed from a different perspective. [Figure 5] This is a top view of a dielectric filter according to an embodiment of the present application. [Figure 6] This is a cross-sectional view of a dielectric filter according to an embodiment of the present application. [Figure 7] This is a diagram showing the structure of another dielectric filter according to an embodiment of this application. [Figure 8] This is a top view of another dielectric filter according to an embodiment of the present application. [Figure 9] This is a diagram showing the arrangement structure of the signal input terminal according to an embodiment of this application. [Figure 10] This diagram shows the signal reflection efficiency of dielectric filters related to the technology. [Figure 11] This figure shows the signal reflection efficiency of a dielectric filter according to an embodiment of this application. [Modes for carrying out the invention]
[0046] The terminology used in the implementation of this application is for the purpose of describing specific embodiments of this application and is not intended to limit this application.
[0047] A dielectric filter is a filtering device formed by coupling between dielectric resonators. Dielectric filters are widely used in communication equipment such as communication base stations, communication satellites, and navigation systems. The filter may allow signals within the passband frequency to pass through while suppressing signals outside the passband frequency. This allows for the acquisition of signals at a predetermined frequency and the effective removal of interfering signals.
[0048] Figure 1 is a diagram of the structure of a dielectric filter related to the relevant technology. Figure 2 is a top view of a dielectric filter related to the relevant technology.
[0049] The related technology provides a dielectric filter 1 with reference to Figures 1 and 2. The dielectric filter 1 includes a dielectric 11. A plurality of resonant blind vias are provided on the upper surface of the dielectric 11, for example, the plurality of resonant blind vias include a first resonant blind via 12 and a second resonant blind via 13. Each resonant blind via and the dielectric surrounding it may form a resonator of the dielectric filter. Between two adjacent resonators, signal energy conversion between an electric field and a magnetic field may occur to achieve coupling between the two resonators. A coupling blind via is further provided between two adjacent resonant blind vias. For example, as shown in Figures 1 and 2, a first coupling blind via 14 (also called a negative coupling deep hole) is provided between the first resonant blind via 12 and the second resonant blind via 13, and the via depth of the first coupling blind via 14 is greater than the depth of the first resonant blind via 12 and the depth of the second resonant blind via 13. The first coupled blind via 14 is used to achieve negative coupling between the resonator containing the first resonant blind via 12 and the resonator containing the second resonant blind via 13.
[0050] Generally, the single-cavity Q-factor of a dielectric filter is directly proportional to the projected size of the dielectric in the axial direction of the resonant blind via. That is, the larger the projected area of the dielectric in the axial direction of the resonant blind via, the larger the single-cavity Q-factor of the dielectric filter, and vice versa. The single-cavity Q-factor of a dielectric filter affects the filtering efficiency of the dielectric filter. That is, the larger the single-cavity Q-factor of the dielectric filter, the smaller the filtering loss of the dielectric filter, and vice versa.
[0051] However, in the above configuration, the coupled blind vias occupy an area on the top surface of the dielectric, causing the dielectric filter to occupy a large area (i.e., on-board footprint) on the mounting substrate. This does not contribute to miniaturizing the dielectric filter. If the on-board footprint of the dielectric filter is reduced by reducing the size of the dielectric filter, the projected area of the dielectric in the axial direction of the resonant blind vias (e.g., the first resonant blind via 12 and the second resonant blind via 13) will also be reduced accordingly, lowering the single cavity Q value of the resonator and increasing the losses of the dielectric filter.
[0052] Furthermore, the first coupled blind via 14 in the dielectric filter reduces the remote suppression capability of the dielectric filter and diminishes its out-of-band suppression effect. Therefore, in the process of using a dielectric filter, a low-pass trace is generally required to suppress out-of-band electromagnetic signals, but the low-pass trace has insertion loss, which increases the loss of the dielectric filter.
[0053] To solve the aforementioned problems, researchers conceived the idea of improving the structure of the dielectric filter. A first resonant blind via and a second resonant blind via are provided on two sides of the dielectric, a first coupling through-hole and a second coupling through-hole are provided on the top surface of the dielectric, and a first connection is provided between the first coupling through-hole and the second coupling through-hole, and by using the first connection, negative coupling may be achieved between the first resonator and the second resonator. When the projected area in the height direction of the dielectric (i.e., from the top surface to the bottom surface of the dielectric) is reduced, the projected area of the dielectric 110 in the axial direction of the resonant blind vias (first resonant blind via and second resonant blind via) is unaffected. In this way, by reducing the projected area in the height direction of the dielectric, the onboard footprint of the dielectric filter can be reduced, and the onboard footprint of the dielectric filter can be reduced without lowering the single cavity Q value of the resonator, thereby effectively achieving miniaturization of the dielectric filter.
[0054] The dielectric filter according to the embodiment of this application will be described in detail below with reference to the attached drawings.
[0055] Figure 3 is a diagram showing the structure of a dielectric filter according to one embodiment of this application, viewed from one viewpoint. Figure 4 is a diagram showing the structure of a dielectric filter according to one embodiment of this application, viewed from another viewpoint. Figure 5 is a top view of a dielectric filter according to one embodiment of this application. Figure 6 is a cross-sectional view of a dielectric filter according to one embodiment of this application.
[0056] This embodiment of the present application provides a dielectric filter 100. Refer to Figures 3 and 4. The dielectric filter 100 may include a dielectric 110. For example, the material forming the dielectric 110 may be ceramic, and the dielectric 110 is integrally molded using an injection molding process. In this way, the structural stability and reliability of the dielectric 110 can be improved. The dielectric 110 has a first side surface 111 and a second side surface 112 that face each other, and an upper surface 113 located between the first side surface 111 and the second side surface 112.
[0057] The dielectric 110 may be provided with at least one group of resonant blind vias. For example, the at least one group of resonant blind vias may include a first group of resonant blind vias 120, and the first group of resonant blind vias 120 (as shown in Figure 6) may include a first resonant blind via 121 and a second resonant blind via 122. The first resonant blind via 121 may be located on a first side surface 111, and the second resonant blind via 122 may be located on a second side surface 112. The first resonant blind via 121 and the dielectric 110 surrounding the first resonant blind via 121 may form a first resonator 123, and the second resonant blind via 122 and the dielectric 110 surrounding the second resonant blind via 122 may form a second resonator 124.
[0058] Refer to Figures 5 and 6. The upper surface 113 of the dielectric 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 upper surface 113 of the dielectric 110 to the bottom surface of the dielectric 110. A first connection portion 142 may be provided between the first coupling through-hole 140 and the second coupling through-hole 141, and negative coupling is realized between the first resonator 123 and the second resonator 124.
[0059] For example, the first coupling through-hole 140 and the second coupling through-hole 141 may be located close to the two sides of the first resonator 123 and the second resonator 124, such that the first connection portion 142 is located near the center of the first resonator 123 and the second resonator 124. The dielectric material 110 at the positions corresponding to the first coupling through-hole 140 and the second coupling through-hole 141 may be removed, and the first connection portion 142 located between the first coupling through-hole 140 and the second coupling through-hole 141 may be left, so that the first resonator 123 and the second resonator 124 may be connected using the dielectric material 110 corresponding to the first connection portion 142. The electromagnetic wave signal may propagate from the first resonator 123 to the second resonator 124 by using the first connection part 142 such that a negative coupling is achieved between the first resonator 123 and the second resonator 124.
[0060] For example, the dielectric filter 100 may further include a conductive layer (not shown), which may cover the surface of the dielectric 110. For example, the conductive layer may be located on the first side surface 111, the second side surface 112, the top surface 113, the bottom surface, the inner wall of the first resonant blind via 121, the inner wall of the second resonant blind via 122, the inner wall of the first coupling through hole 140, and the inner wall of the second coupling through hole 141 of the dielectric 110. The dielectric filter 100 may be understood as a closed cavity formed by the conductive layer and filled with the dielectric 110.
[0061] For example, after the dielectric 110 is formed, a metal layer may be coated onto the surface of the dielectric 110 by methods such as spraying or coating in order to form a conductive layer. For example, the material of the conductive layer may be silver.
[0062] During operation, electromagnetic signals may enter the dielectric filter 100 through its signal input port and propagate within the dielectric 110. Electromagnetic signals propagate from one resonator to another adjacent resonator. For example, electromagnetic signals may propagate from the first resonator 123 to the second resonator 124 by using the first connection 142 between the first coupling through-hole 140 and the second coupling through-hole 141. An electric field exists near the center of the resonator, and a magnetic field exists near the edges of the resonator, i.e., near the conductive layer. The energy of the electric field and magnetic field are continuously exchanged so that the dielectric filter 100 produces electromagnetic resonance at several approximate frequencies, and the resonant energy may be transmitted from the input end to the output end of the dielectric filter 100. Electric field coupling and magnetic field coupling exist between different resonators so that a passband can be formed between them. Only signals with frequencies within the passband can pass through; signals of other frequencies cannot, thereby achieving a filtering effect.
[0063] When the electromagnetic wave signal reaches the conductive layer covering the dielectric 110, the electromagnetic wave signal may be reflected by the conductive layer. After the signal is repeatedly reflected within the dielectric filter 100, a portion of the signal is totally reflected and ultimately output from the signal output terminal of the dielectric filter 100, while another portion of the signal cannot be totally reflected within the dielectric 110 so that the signal is removed and returns to the signal input terminal through its original path.
[0064] In the process of an electromagnetic wave signal propagating from the first resonator 123 to the second resonator 124, negative coupling may be realized between the first resonator 123 and the second resonator 124. Negative coupling, also called electrical coupling, means that in the process of coupling the first resonator 123 to the second resonator 124, the conversion from an electric field to a magnetic field is mainly used. That is, by using the first connection part 142, the electric field is mainly used in the process of coupling the first resonator 123 to the second resonator 124. Negative coupling may generate zero transmission (see point A in Figure 11), which can enhance the suppression effect and improve the suppression effect of the dielectric filter 100 on a signal at a certain frequency so that the signal corresponding to that frequency is well suppressed. For example, if a high suppression requirement is needed for a signal of a certain frequency during the use of the dielectric filter 100, negative coupling may be provided within the dielectric filter 100 such that the coupling between multiple resonators is negative, thereby achieving strong suppression for the signal of that frequency.
[0065] The size of the first connection portion 142 may affect the size of the coupling channel (also called a window) between the first resonator 123 and the second resonator 124. The larger the cross-sectional area of the first connection portion 142 in the direction from the first resonator 123 to the second resonator 124, the wider the coupling channel between the first resonator 123 and the second resonator 124 becomes, and the larger the frequency bandwidth of the signal that can pass through the coupling channel becomes. In this case, the amount of coupling between the first resonator 123 and the second resonator 124 becomes, and the larger the amount of coupling, the wider the bandwidth becomes.
[0066] In contrast, the smaller the cross-sectional area of the first connection portion 142 in the direction from the first resonator 123 to the second resonator 124, the narrower the coupling channel between the first resonator 123 and the second resonator 124 becomes, and the smaller the frequency bandwidth of the signal that can pass through the coupling channel becomes. In this case, the amount of coupling between the first resonator 123 and the second resonator 124 becomes smaller, and the smaller the amount of coupling, the narrower the bandwidth becomes.
[0067] Therefore, in order to change the amount of coupling between the first resonator 123 and the second resonator 124, the size of the first coupling through-hole 140 may be changed by changing the size of the first coupling through-hole 140, for example, by changing the size of the cross-sectional area of the first coupling through-hole 140 in the direction from the first resonator 123 to the second resonator 124.
[0068] During the installation process of the dielectric filter 100, the bottom surface of the dielectric filter 100 may be mounted on the mounting substrate, and the area occupied when the dielectric filter 100 is mounted on the mounting substrate may be understood as the onboard footprint of the dielectric filter 100.
[0069] Compared with related techniques in which resonant blind vias and coupled blind vias are provided on the upper surface of a dielectric to achieve negative coupling between two resonators, in this embodiment of the present application, the first resonant blind via 121 and the second resonant blind via 122 are provided on the side surface of the dielectric 110 so as to achieve negative coupling between the first resonator 123 and the second resonant blind via 124, and the first coupled through-hole 140 and the second coupled through-hole 141 are provided on the upper surface 113 of the dielectric 110. Even if the projected area of the dielectric 110 in the height direction (i.e., from the upper surface to the lower surface of the dielectric) is reduced, the projected area of the dielectric 110 in the axial direction of the resonant blind vias (first resonant blind via 121 and second resonant blind via 122) is not affected. In this way, by reducing the projected area of the dielectric 110 in the height direction, the onboard footprint of the dielectric filter 100 can be reduced, and the onboard footprint of the dielectric filter 100 can be reduced without lowering the single cavity Q value of the resonator, thereby effectively achieving miniaturization of the dielectric filter 100.
[0070] Furthermore, compared to resonant blind vias in dielectric filters in related technologies, all resonant blind vias (first resonant blind via 121 and second resonant blind via 122) of the dielectric filter 100 provided in this embodiment of the present application are provided on two sides of the dielectric 110. In this way, crosstalk between resonators can be reduced. In addition, the design of a negative coupling hole (i.e., the first coupling blind via 14 in Figure 1) is not required. In this way, the remote suppression capability of the dielectric filter 100 can be effectively improved, and the out-of-band suppression effect can be effectively enhanced. It may not be necessary to provide a low-pass trace, and insertion losses caused by excessive low-pass traces can be avoided, thereby effectively reducing the losses of the dielectric filter.
[0071] Refer to Figures 5 and 6. The dielectric 110 may further include a second group of resonant blind vias 130, the second group of resonant blind vias 130 may include a third resonant blind via 131 and a fourth resonant blind via 132. The third resonant blind via 131 and the dielectric 110 surrounding the third resonant blind via 131 may form a third resonator 133, and the fourth resonant blind via 132 and the dielectric 110 surrounding the fourth resonant blind via 132 may form a fourth resonator 134.
[0072] A third coupling through-hole 143 may be provided on the upper surface 113 of the dielectric 110, and two second connecting parts 144 may be provided on the two sides of the third coupling through-hole 143, thereby achieving positive coupling between the third resonator 133 and the fourth resonator 134 by using the two second connecting parts 144. Positive coupling is also called magnetic coupling, and means that a magnetic field is mainly used in the process of coupling the third resonator 133 to the fourth resonator 134.
[0073] For example, the third coupling through-hole 143 may be located near the center of the third resonator 133 and the fourth resonator 134 such that the dielectric material 110 is removed at the central position between the third resonator 133 and the fourth resonator 134, and the dielectric 110 between the third resonator 133 and the fourth resonator 134 is left near both sides to form two second connection portions 144. The third resonator 133 and the fourth resonator 134 may be connected by using the dielectric material 110 corresponding to the two second connection portions 144. In this way, electromagnetic wave signals may propagate from the third resonator 133 to the fourth resonator 134 by using the two second connection portions 144 located near both sides, so that a positive coupling is achieved between the third resonator 133 and the fourth resonator 134.
[0074] The size of the second connection portion 144 may affect the size of the coupling channel (also called a window) between the third resonator 133 and the fourth resonator 134. The larger the cross-sectional area of the second connection portion 144 in the direction from the third resonator 133 to the fourth resonator 134, the wider the coupling channel between the third resonator 133 and the fourth resonator 134 becomes. In this case, the amount of coupling between the third resonator 133 and the fourth resonator 134 becomes larger.
[0075] In contrast, the smaller the cross-sectional area of the second connection portion 144 in the direction from the third resonator 133 to the fourth resonator 134, the narrower the coupling channel between the third resonator 133 and the fourth resonator 134 becomes. In this case, the amount of coupling between the third resonator 133 and the fourth resonator 134 becomes smaller. Therefore, in order to change the amount of coupling between the third resonator 133 and the fourth resonator 134, the size of the second connection portion 144 may be changed by changing the size of the third coupling through-hole 143, for example, by changing the size of the cross-sectional area of the third coupling through-hole 143 in the direction from the third resonator 133 to the fourth resonator 134.
[0076] Refer to Figure 5 again. In possible implementations, the dielectric 110 may further include a first coupling slot 145, and both a first coupling through-hole 140 and a second coupling through-hole 141 may be provided in the bottom wall of the first coupling slot 145. To further reduce the size of the first connection portion 142, material of the dielectric 110 may be removed at the location of the first connection portion 142 near the top surface 113 of the dielectric 110 for the first coupling slot 145, and the size of the coupling channel between the first resonator 123 and the second resonator 124 may be adjusted to change the amount of coupling between the first resonator 123 and the second resonator 124.
[0077] For example, when the size of the first coupling slot 145 in the direction from the top surface 113 to the bottom surface of the dielectric 110 is large, that is, when the depth of the first coupling slot 145 is large, the cross-sectional area of the first coupling slot 145 in the direction from the third resonator 133 to the fourth resonator 134 also increases, so that the cross-sectional area of the first connection portion 142 in the direction from the first resonator 123 to the second resonator 124 decreases, and the amount of coupling between the first resonator 123 and the second resonator 124 can be reduced.
[0078] In contrast, when the size of the first coupling slot 145 in the direction from the upper surface 113 to the lower surface of the dielectric 110 is small, that is, when 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 becomes smaller, so as to increase the cross-sectional area of the first connection portion 142 in the direction from the first resonator 123 to the second resonator 124, thereby increasing the amount of coupling between the first resonator 123 and the second resonator 124.
[0079] Refer to Figure 5 again. In another possible implementation, the top surface 113 of the dielectric 110 may further include a second coupling slot 146, and a third coupling through-hole 143 may be provided in the bottom wall of the second coupling slot 146. To further reduce the size of the second coupling portion 144, material of the dielectric 110 may be removed at the location of the second coupling portion 144 near the top surface 113 of the dielectric 110 for the second coupling slot 146, and to achieve a wider variety of coupling amounts between the third resonator 133 and the fourth resonator 134, the size of the coupling channel between the third resonator 133 and the fourth resonator 134 may be adjusted to change the coupling amount between the third resonator 133 and the fourth resonator 134.
[0080] For example, when the size of the second coupling slot 146 in the direction from the top surface 113 to the bottom surface of the dielectric 110 is large, that is, when the depth of the second coupling slot 146 is deep, the cross-sectional area of the second coupling slot 146 in the direction from the third resonator 133 to the fourth resonator 134 becomes smaller, and the amount of coupling between the third resonator 133 and the fourth resonator 134 can be reduced.
[0081] In contrast, when the size of the second coupling slot 146 in the direction from the top surface 113 to the bottom surface of the dielectric 110 is small, that is, when 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 becomes smaller, so as to increase the cross-sectional area of the second connection portion 144 in the direction from the third resonator 133 to the fourth resonator 134, thereby increasing the amount of coupling between the third resonator 133 and the fourth resonator 134.
[0082] Alternatively, in yet another possible implementation, still referring to Figures 5 and 6, a third coupling slot 147 may be provided on the upper surface 113 of the dielectric 110, and all of the first coupling through-hole 140, the second coupling through-hole 141, and the third coupling through-hole 143 may be provided on the bottom wall of the third coupling slot 147. In this case, the first coupling slot 145 may be understood to be connected to the second coupling slot 146. For example, the third coupling slot 147 may penetrate from one end of the dielectric 110 to the other, and the first coupling through-hole 140, the second coupling through-hole 141, and the third coupling through-hole 143 may be provided separately on the bottom wall of the third coupling slot 147.
[0083] Refer to Figures 5 and 6 thereafter. In some examples, a fifth coupling through-hole 151 may be further provided in the upper surface 113 of the dielectric, and the fifth coupling through-hole 151 may be located between two adjacent resonant blind via groups. For example, in this embodiment of the application, the fifth coupling through-hole 151 may be provided between a first resonant blind via group 120 and a second resonant blind via group 130 that are adjacent to each other. The fifth coupling through-hole 151 may further 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 different coupling amounts can be achieved between two adjacent resonators.
[0084] Let us take the coupling between the first resonator 123 and the third resonator 133 as an example. The fifth coupling through-hole 151 may be a long through-hole as shown in Figure 5. In this case, the cross-sectional area of the fifth coupling through-hole 151 in the direction from the first resonator 123 to the third resonator 133 can be increased so that the coupling channel between the first resonator 123 and the third resonator 133 can be reduced, and the amount of coupling between the first resonator 123 and the third resonator 133 can be further reduced.
[0085] Alternatively, the fifth coupling through-hole 151 may be a cylindrical through-hole. In this case, the cross-sectional area of the fifth coupling through-hole 151 in the direction from the first resonator 123 to the third resonator 133 can be reduced so that the coupling channel between the first resonator 123 and the third resonator 133 can be increased, thereby achieving a large coupling amount between the first resonator 123 and the third resonator 133.
[0086] In this embodiment of the present application, there may be a plurality of first resonant blind via groups 120 and a plurality of second resonant blind via groups 130, and the plurality of first resonant blind via groups 120 and the plurality of second resonant blind via groups 130 may be arranged alternately. For example, as shown in Figure 6, there may be two first resonant blind via groups 120 and three second resonant blind via groups 130. Here, there may be one first resonant blind via group 120 between the two second resonant blind via groups 130.
[0087] The arrangement of the first resonant blind via group 120 and the second resonant blind via group 130 may affect the filtering result of the dielectric filter 100. For example, when the first resonant blind via group 120 and the second resonant blind via group 130 are arranged alternately, the dielectric filter 100 may acquire signals in a certain frequency band and filter out other signals outside that frequency band. When the first resonant blind via group 120 and the second resonant blind via group 130 are arranged in a different way, for example, the dielectric filter 100 may acquire signals in a different frequency band and filter out signals outside that frequency band.
[0088] For example, in some cases, instead, multiple first resonant blind via groups 120 may be arranged adjacently in sequence, or multiple second resonant blind via groups 130 may be arranged in sequence. Specifically, the arrangement of the first resonant blind via groups 120 and the second resonant blind via groups 130 may be selected and set based on the filtering requirements of the dielectric filter 100. This embodiment of the present application will be described using an example in which the first resonant blind via groups 120 and the second resonant blind via groups 130 are arranged alternately.
[0089] Figure 7 is a diagram of the structure of another dielectric filter according to one embodiment of this application. Figure 8 is a top view of another dielectric filter according to one embodiment of this application.
[0090] Instead, in some examples, with reference to Figures 7 and 8, a fourth coupling slot 148 may be provided on the upper surface 113 of the dielectric 110, and the first coupling through-hole 140 and the third coupling through-hole 143 may be provided on the bottom wall of the fourth coupling slot 148. For example, a first group of resonators (i.e., a resonator including a first group of resonant blind vias 120) and a second group of resonators (i.e., a resonator including a second group of resonant blind vias 130) may be arranged adjacent to each other. In this case, a fourth coupling slot 148 may be provided on the upper surface 113 of the dielectric 110, and the fourth coupling slot 148 may extend from the first group of resonators to the position where the first coupling through-hole 140 is provided in the second group of resonators, and the first coupling through-hole 140 and the third coupling through-hole 143 may be provided on the bottom wall of the fourth coupling slot 148.
[0091] Refer to Figures 7 and 8. The dielectric 110 may further be provided with a fourth coupling through-hole 149, which may be located on the first side surface 111 or the second side surface 112 of the dielectric 110, and may be located between two adjacent resonant blind via groups.
[0092] For example, in this embodiment of the present application, the fourth coupling through-hole 149 may be provided between a first resonant blind via group 120 and a second resonant blind via group 130 that are adjacent to each other. Resonators containing two adjacent resonant blind vias located on the same side surface may also be coupled. For example, a first resonator 123 containing a first resonant blind via 121 may be coupled to a third resonator 133 containing a third resonant blind via 131. Correspondingly, a second resonator 124 may also be coupled to a fourth resonator 134. The fourth coupling through-hole 149 may adjust the size of the coupling channel between the first resonator 123 and the third resonator 133, or the size of the coupling channel between the second resonator 124 and the fourth resonator 134.
[0093] For example, when the fourth coupling through-hole 149 is located on the first side surface 111 of the dielectric 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 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.
[0094] Let us take the coupling between the first resonator 123 and the third resonator 133 as an example. The fourth coupling through-hole 149 may be a cylindrical through-hole, and the cross-sectional area of the fourth coupling through-hole 149 in the 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 becomes large so that a large coupling amount can be achieved between the first resonator 123 and the third resonator 133. Alternatively, the fourth coupling through-hole 149 may be a long through-hole, and the cross-sectional area of the fourth coupling through-hole 149 in the 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 becomes small so that a small coupling amount can be achieved between the first resonator 123 and the third resonator 133.
[0095] In certain application processes, the shape and size of the cross-sectional area of the fourth coupling through-hole 149 may be designed based on the requirements for the amount of coupling between the first resonator 123 and the third resonator 133.
[0096] Correspondingly, the fourth coupling through-hole 149 also has a similar function for controlling the amount of coupling between the second resonator 124 and the fourth resonator 134. Further details will not be explained here.
[0097] 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 arranged, 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 offset from each other. Specifically, the arrangement 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 specific application requirements.
[0098] Alternatively, in some examples, a fifth coupling slot 150 (see Figures 3 and 4) may be provided on the upper surface 113 of the dielectric 110, which may penetrate from the first side surface 111 to the second side surface 112 of the dielectric 110, and may be located between two adjacent resonant blind via groups. For example, in this embodiment of the application, the fifth coupling slot 150 may be provided between a first resonant blind via group 120 and a second resonant blind via group 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 different coupling amounts can be achieved between two adjacent resonators.
[0099] Next, we will use the coupling between the first resonator 123 and the third resonator 133 as an example. The deeper the fifth coupling slot 150, the larger the cross-sectional area of the fifth coupling slot 150 in the direction from the first resonator 123 to the third resonator 133, the narrower the coupling channel between the first resonator 123 and the third resonator 133, and the smaller the amount of coupling between the first resonator 123 and the third resonator 133. Conversely, the shallower the fifth coupling slot 150, the smaller the cross-sectional area of the fifth coupling slot 150 in the direction from the first resonator 123 to the third resonator 133, the wider the coupling channel between the first resonator 123 and the third resonator 133, and the smaller the amount of coupling between the first resonator 123 and the third resonator 133. In a particular application process, the depth size of the fifth coupling slot 150 may be designed based on the requirements for the amount of coupling between the first resonator 123 and the third resonator 133.
[0100] In this embodiment of the present application, the first resonant blind via 121 and the second resonant blind via 122 of the first resonant blind via group 120 may be provided coaxially, and the third resonant blind via 131 and the fourth resonant blind via 132 of the second resonant blind via group 130 may also be provided coaxially. In this way, the normalization of the overall structure of the dielectric filter 100 can be improved, and the design and manufacture of the dielectric filter 100 can be facilitated. Furthermore, when performing simulation calculations on the dielectric filter 100, the size of each resonant blind via in the dielectric filter 100 can be conveniently determined, thereby improving work efficiency.
[0101] Figure 9 is a diagram showing a structure for arranging a signal input terminal according to one embodiment of this application.
[0102] In this embodiment of the present application, with reference to Figure 9, the dielectric filter 100 may further include a signal input terminal 160, which may be signal-connected to a first resonator 123. An electromagnetic wave signal may be input from the signal input terminal 160 and enter the dielectric filter 100 through the first resonator 123.
[0103] For example, as shown in Figure 9, the dielectric 110 may further include a first coupled blind via 161. One end of the first coupled blind via 161 may be connected to the signal input terminal 160, and the other end of the first coupled blind via 161 may be connected to the first resonant blind via 121. The signal input terminal 160 may coupled-supply the first resonator 123 through the first coupled blind via 161 so that an electromagnetic wave signal can be supplied to the dielectric filter 100.
[0104] Indeed, in some examples, the signal input terminal 160 may instead be signal-connected to a second resonator 124, a third resonator 133, or a fourth resonator 134 to realize the input of an electromagnetic wave signal.
[0105] Refer to Figure 9. The dielectric 110 may further include 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 resonant blind via 121. The signal input terminal 160 may coupled-supply the first resonator 123 by passing the signal through the first coupling blind via 161 and the sixth coupling slot 162 in sequence to realize a signal input.
[0106] Correspondingly, the dielectric filter 100 may further include a signal output terminal (not shown). The signal output terminal may be signal-connected to a second resonator 124. After being powered to the dielectric filter 100 from the signal input terminal 160, the electromagnetic wave signal may be repeatedly reflected within the dielectric 110 and finally output from the signal output terminal to complete the filtering function of the dielectric filter 100.
[0107] For the configuration of the signal connection between the signal output terminal and the second resonator, please refer to the connection between the signal input terminal 160 and the first resonator 123. Further details will not be explained here.
[0108] Alternatively, in some examples, the signal output terminal may be signal-connected to a second resonator 124, a third resonator 133, or a fourth resonator 134 to realize the output of an electromagnetic wave signal.
[0109] One embodiment of this application further provides a communication device. The communication device may include a dielectric filter 100 in any one of the examples described above. For example, the communication device may be a communication base station, satellite communication, or navigation system. The dielectric filter 100 may filter interference signals in the communication device to improve signal stability and reliability during operation of the communication device.
[0110] The communication device includes the dielectric filter 100 so as to effectively reduce the installation space occupied by the dielectric filter 100 within the communication device, thereby improving the rationality and normalization of the layout of the internal components of the communication device.
[0111] For example, the communication device may further include an antenna, which may be signal-connected to the dielectric filter 100. The antenna may be configured to transmit and receive signals. The dielectric filter 100 may be configured to filter the signals received by the antenna, or to transmit the filtered signals to the antenna.
[0112] The following simulation tests will be performed on the dielectric filter 100 provided in this embodiment of the present application, with reference to the attached drawings.
[0113] Figure 10 is a diagram showing the signal reflection efficiency of a dielectric filter in related technology. Figure 11 is a diagram showing the signal reflection efficiency of a dielectric filter according to one embodiment of this application.
[0114] Refer to Figure 10. In the figure, the horizontal axis represents frequency, and the vertical axis represents signal power. The further the value on the vertical axis of the curve in the figure is from 0, the less signal is transmitted from the input terminal to the output terminal. In other words, the signal at that frequency is filtered by the dielectric filter 100 and is not output from the signal output terminal. Conversely, the closer the value on the vertical axis of the curve in the figure is to 0, the more signal is transmitted from the input terminal to the output terminal. This indicates that the signal at that frequency passes through the dielectric filter 100 and is output from the output terminal of the dielectric filter 100.
[0115] Therefore, Figure 10 shows that the dielectric filter 100 in the related technology has a resonance point in a frequency band with a center frequency of 3.5 GHz, and signals within this frequency band pass through the dielectric filter 100. Furthermore, Figure 10 shows that two low-frequency resonance points appear at a frequency around 2.5 GHz, and at these frequencies, signal reflection is small, indicating that some of the energy passes through the dielectric filter 100. This indicates that the signal suppression effect of the dielectric filter 100 is insufficient at these frequencies.
[0116] Furthermore, in the frequency band from 6.0 GHz to 6.5 GHz, higher-order mode resonance occurs in the dielectric filter 100, meaning that out-of-band resonance modes exist. Out-of-band resonance modes mean that the dielectric filter 100 resonates outside the passband. Higher-order mode resonance is an out-of-band resonance mode where the resonance frequency is approximately twice or multiple times the passband frequency. This generates a parasitic passband at approximately twice or multiple times the passband frequency, and as a result, the suppression effect of the filter at approximately twice or multiple times the passband frequency deteriorates. Therefore, it can be seen from the figure that the dielectric filter 100 in the related technology has a low suppression effect on higher-order mode signals.
[0117] Generally, in related technologies, in order to solve the problem of higher-order mode resonance, when using a dielectric filter 100, it is necessary to add a low-pass trace stub line to the dielectric filter 100 to suppress higher-order mode signals, which increases insertion loss and thus increases the loss of the dielectric filter. Furthermore, the overall layout area and cost of the dielectric filter increase.
[0118] Figure 11 shows the signal reflection efficiency of a dielectric filter 100 according to one embodiment of this application. Figure 11 shows that a resonance point exists in a frequency band with a center frequency of 3.5 GHz, and that signals within this frequency band pass through the dielectric filter 100. Furthermore, the low-frequency resonance and higher-order mode resonance that occurred in Figure 10 do not occur. In this way, it is not necessary to provide a low-pass trace stub when using the dielectric filter 100, thereby avoiding the problem of insertion loss caused by an increase in low-pass traces, and effectively reducing the loss and cost of the dielectric filter 100.
[0119] In the description of embodiments of this application, unless otherwise explicitly provided and limited, the terms “installation,” “interconnection,” or “connection” should be understood broadly, and may include, for example, a fixed connection, an indirect connection via an intermediate medium, an internal connection between two components, or an interaction relationship between two components. Those skilled in the art will be able to understand the specific meaning of the aforementioned terms in embodiments of this application based on the particular circumstances. Terms such as “first,” “second,” “third,” “fourth,” etc. (if any) are intended to distinguish similar objects and do not necessarily indicate a particular order or sequence.
[0120] Finally, the embodiments described above are used solely to illustrate the technical solutions in the embodiments of this application, but do not limit the technical solutions. Although the embodiments of this application have been described in detail with reference to the embodiments described above, those skilled in the art should understand that the technical solutions described in the embodiments above may still be modified, or some or all of their technical features may be replaced with equivalents. However, such modifications or replacements do not depart from the scope of the technical solutions in the embodiments of this application. [Explanation of Symbols]
[0121] 100 Dielectric filter, 110 Dielectric, 111 First side, 112 Second side, 120 First resonant blind via group, 121 First resonant blind via, 122 Second resonant blind via, 123 First resonator, 124 Second resonator, 130 Second resonant blind via group, 131 Third resonant blind via, 132 Fourth resonant blind via, 133 Third resonator, 134 Fourth resonator, 140 First connecting through hole, 141 Second connecting through hole, 142 First connection part, 143 Third connecting through hole, 144 Second connection part, 145 First connecting slot, 146 Second joint slot, 147 Third joint slot, 148 Fourth joint slot, 149 Fourth bonding through hole, 150 Fifth bonding slot, 151 Fifth bonding through hole, 160 signal input terminal, 161 first coupled blind via, 162 sixth coupled slot.
Claims
1. A dielectric filter comprising a dielectric, The dielectric material has a first side surface and a second side surface facing each other, and an upper surface located between the first side surface and the second side surface. The dielectric is provided with at least one group of resonant blind vias, the at least one group of resonant blind vias includes a first group of resonant blind vias, the first group of resonant blind vias includes a first resonant blind via and a second resonant blind via, The first resonant blind via is located on the first side, and the second resonant blind via is located on the second side. The first resonant blind via and the dielectric surrounding the first resonant blind via form a first resonator, and the second resonant blind via and the dielectric surrounding the second resonant blind via form a second resonator. The upper surface of the dielectric is provided with a first coupling through-hole and a second coupling through-hole, and a first connecting portion is provided between the first coupling through-hole and the second coupling through-hole, and a negative coupling is achieved between the first resonator and the second resonator via the first connecting portion. Dielectric filter.
2. The aforementioned at least one group of resonant blind vias further comprises a second group of resonant blind vias, the second group of resonant blind vias comprising a third resonant blind via and a fourth resonant blind via. The third resonant blind via is located on the first side, and the fourth resonant blind via is located on the second side. The third resonant blind via and the dielectric surrounding the third resonant blind via form a third resonator, and the fourth resonant blind via and the dielectric surrounding the fourth resonant blind via form a fourth resonator. A third coupling through-hole is provided on the upper surface of the dielectric, and two second connecting portions are provided on both sides of the third coupling through-hole. By using the two second connecting portions, a positive coupling is achieved between the third resonator and the fourth resonator. The dielectric filter according to claim 1.
3. A first coupling slot is further provided on the upper surface of the dielectric, and both the first coupling through-hole and the second coupling through-hole are provided in the bottom wall of the first coupling slot. The dielectric filter according to claim 2.
4. A second coupling slot is further provided on the upper surface of the dielectric, and a third coupling through-hole is provided in the bottom wall of the second coupling slot. The dielectric filter according to claim 2 or 3.
5. A third coupling slot is further provided on the upper surface of the dielectric, and the bottom wall of the third coupling slot is provided with all of the first coupling through-hole, the second coupling through-hole, and the third coupling through-hole. A dielectric filter according to any one of claims 2 to 4.
6. A fourth coupling slot is further provided on the upper surface of the dielectric, and both the first coupling through-hole and the third coupling through-hole are provided in the bottom wall of the fourth coupling slot. A dielectric filter according to any one of claims 2 to 5.
7. The dielectric is further provided with a fourth coupling through-hole, The fourth coupling through-hole is located on the first or second side surface of the dielectric, and the fourth coupling through-hole is located between two adjacent resonant blind via groups. A dielectric filter according to any one of claims 2 to 6.
8. A fifth coupling slot is further provided on the upper surface of the dielectric, The fifth coupling slot penetrates the dielectric from the first side to the second side, and is located between two adjacent resonant blind via groups. A dielectric filter according to any one of claims 2 to 6.
9. A fifth coupling through-hole is further provided on the upper surface of the dielectric, The fifth coupling through-hole is located between two adjacent resonant blind via groups. Further including, A dielectric filter according to any one of claims 2 to 6.
10. There are multiple first resonant blind via groups and multiple second resonant blind via groups. The plurality of first resonant blind via groups and the plurality of second resonant blind via groups are arranged alternately. A dielectric filter according to any one of claims 2 to 9.
11. The first resonant blind via and the second resonant blind via in the first resonant blind via group are provided coaxially. The third and fourth resonant blind vias in the second resonant blind via group are provided coaxially. A dielectric filter according to any one of claims 2 to 10.
12. The dielectric filter further comprises a conductive layer, the conductive layer covering the surface of the dielectric, A dielectric filter according to any one of claims 1 to 11.
13. The dielectric filter further comprises a signal input terminal, The signal input terminal is signal-connected to the first resonator. A dielectric filter according to any one of claims 1 to 12.
14. The dielectric is further provided with a first coupled blind via. One end of the first coupled blind via is connected to the signal input terminal, and the other end of the first coupled blind via is connected to the first resonant blind via. The dielectric filter according to claim 13.
15. The dielectric is further provided with a sixth coupling slot, 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 resonant blind via. The dielectric filter according to claim 14.
16. The dielectric filter further comprises a signal output terminal, The aforementioned signal input terminal is signal-connected to the second resonator. A dielectric filter according to any one of claims 1 to 15.
17. A dielectric filter according to any one of claims 1 to 16, Communication device.
18. The communication device further comprises an antenna, the antenna being signal-connected to the dielectric filter. The communication device according to claim 17.