A dielectric filter and a communication device

Abstract

The application discloses a dielectric filter and a communication device, and effectively reduces the loss of the dielectric filter. The dielectric filter comprises a dielectric block, a dielectric layer and a metal layer. In the dielectric filter, the dielectric constant of the dielectric layer is smaller than the dielectric constant of the dielectric block, at least one surface of the dielectric block is covered by the dielectric layer, and the surface of the dielectric layer and the surface of the dielectric block not covered by the dielectric layer are covered by the metal layer.

Description

Technical Field

[0001] This application relates to the field of communication technology, specifically to a dielectric filter and a communication device. Background Technology

[0002] With the rapid development of wireless communication technology, communication devices (such as base stations) in wireless communication architectures are becoming increasingly densely distributed, placing ever smaller demands on their size. In 5G (5th generation mobile networks) multiple-input multiple-output (MIMO) scenarios, the number of transmission channels increases dramatically, leading to a corresponding increase in the number of filters. Therefore, the size requirements for filters are relatively high. Dielectric filters in communication devices, due to the high dielectric constant of the dielectric material, allow for miniaturization and offer advantages such as ease of production and low cost, and are already widely used in 5G base station products. However, because dielectric filters are significantly smaller than traditional metal cavity filters, according to basic electromagnetic theory, reduced size leads to increased losses. Therefore, reducing the losses of dielectric filters is particularly urgent.

[0003] In existing dielectric filter technologies, metallization is performed directly on the surface of the dielectric block to form a metal layer. When electromagnetic waves from the dielectric block reach the metal layer, total internal reflection occurs, resulting in a current flowing through the metal layer's surface. However, since the metal layer is a non-ideal conductor, the current flowing through it incurs losses, leading to significant losses in the dielectric filter.

[0004] Therefore, how to reduce the loss of dielectric filters has become an urgent problem to be solved. Summary of the Invention

[0005] This application provides a dielectric filter and a communication device that effectively reduce the loss of the dielectric filter.

[0006] Firstly, embodiments of this application provide a dielectric filter. The dielectric filter includes a dielectric block, a dielectric layer, and a metal layer. In this dielectric filter, the dielectric constant of the dielectric layer is lower than the dielectric constant of the dielectric block. Furthermore, at least one surface of the dielectric block is covered by the dielectric layer, and the surface of the dielectric layer and the surface of the dielectric block not covered by the dielectric layer are covered by the metal layer. It should be noted that the material of the described dielectric block can be a dielectric material with a high dielectric constant and low loss, such as ceramic. The material of the described metal layer can be a metal such as silver, copper, aluminum, titanium, tin, or gold. Through this method, since the dielectric constant and wave impedance of the dielectric block are different from those of the dielectric layer, electromagnetic waves propagating from the dielectric block are partially reflected after reaching the dielectric layer, allowing energy to be gradually reflected back. Therefore, less energy reaches the metal layer in the end, resulting in less current loss on the surface of the metal layer, thereby effectively reducing the loss of the dielectric filter.

[0007] In some possible implementations, the dielectric layer comprises N layers, with K dielectric layers covering a first surface of the dielectric block and P dielectric layers covering a second surface of the dielectric block. The first surface and the second surface are not the same, and the first surface and the second surface are one or more of the at least one surface, where N is a positive integer and K and P ≤ N. In this example, the dielectric block may have one or more surfaces, and the first surface may be covered with K dielectric layers, which can be stacked. Similarly, the second surface may be covered with P dielectric layers, which can also be stacked. By stacking the same or different numbers of dielectric layers on different surfaces of the dielectric block, the loss of the dielectric filter can be reduced to varying degrees.

[0008] In some possible implementations, each of the N dielectric layers has the same dielectric constant; or, the dielectric constant of each of the N dielectric layers may not be the same.

[0009] In some possible implementations, K may be the same as P, or K may be different from P. That is, the number of dielectric layers covering the first surface of the dielectric block may be the same as the number of dielectric layers covering the second surface of the dielectric block, or they may be different.

[0010] In some possible implementations, the material of the dielectric block includes ceramic.

[0011] In some possible implementations, the material of the dielectric filter includes silicon oxide, boron oxide, calcium oxide, and / or aluminum oxide.

[0012] In some possible implementations, the surface of the medium block includes at least one hole and / or at least one groove.

[0013] In some possible implementations, the surface of the medium block does not include holes and / or grooves.

[0014] Secondly, embodiments of this application provide a communication device. This communication device includes a dielectric filter as described in the first aspect and any possible implementation thereof. The described dielectric filter can be applied in the transceiver channel of a communication system, and in the radio frequency front-end filter circuit connected to the transceiver channel of the communication system, to achieve frequency selection of the transmitted and received signals. It should be noted that the described communication device can be a base station, satellite communication equipment, or terminal capable of 4G communication, 5G communication, or a future base station, satellite communication equipment, or terminal capable of 6G communication; this application does not impose any limitations.

[0015] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0016] In this embodiment, because the dielectric constant of the dielectric block is greater than that of the dielectric layer, the dielectric constant and wave impedance of the dielectric block and the dielectric layer are different. Therefore, by attaching the dielectric layer to the surface of the dielectric block and the metal layer to the surface of the dielectric layer, some electromagnetic waves propagating from the dielectric block are reflected upon reaching the dielectric layer. This allows energy to be gradually reflected back, resulting in less energy reaching the metal layer. Consequently, the current loss on the surface of the metal layer is reduced, effectively lowering the loss of the dielectric filter. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0018] Figure 1 This is a schematic diagram of the structure of a dielectric filter in an existing scheme;

[0019] Figure 2A A cross-sectional schematic diagram of a dielectric filter provided in an embodiment of this application;

[0020] Figure 2B Another cross-sectional schematic diagram of the dielectric filter provided in an embodiment of this application;

[0021] Figure 3A Another cross-sectional schematic diagram of the dielectric filter provided in an embodiment of this application;

[0022] Figure 3B Another cross-sectional schematic diagram of the dielectric filter provided in an embodiment of this application;

[0023] Figure 4A Another cross-sectional schematic diagram of the dielectric filter provided in an embodiment of this application;

[0024] Figure 4B Another cross-sectional schematic diagram of the dielectric filter provided in an embodiment of this application;

[0025] Figure 5A This is a schematic diagram of one configuration of the dielectric filter provided in an embodiment of this application;

[0026] Figure 5B This is a schematic diagram of another form of the dielectric filter provided in an embodiment of this application;

[0027] Figure 5C This is a schematic diagram of another form of the dielectric filter provided in an embodiment of this application;

[0028] Figure 6 This is a schematic diagram of a communication device provided in an embodiment of this application. Detailed Implementation

[0029] This application provides a dielectric filter and a communication device that effectively reduce the loss of the dielectric filter.

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0031] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that implementations of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion. In this application, “at least one” means one or more, and “more than one” means two or more. “And / or” describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character “ / ” generally indicates that the preceding and following related objects are in an “or” relationship. “At least one of the following” or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c" can be expressed as: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be a single item or multiple items. It is worth noting that "at least one of a kind" can also be interpreted as "one item or multiple items".

[0032] Dielectric filters in communication equipment have been widely used in 5G communication technology due to their advantages such as high dielectric constant, small size, ease of production, and low cost. However, since dielectric filters are significantly smaller than traditional metal cavity filters, according to basic electromagnetic theory, reduced size inevitably leads to increased losses. Therefore, reducing the losses of dielectric filters is particularly urgent.

[0033] Figure 1 This is a schematic diagram of the structure of a dielectric filter in an existing scheme. (Example:) Figure 1 As shown, metallization is performed directly on the surface of the dielectric block 101 to form a metal layer 102. When electromagnetic waves from the dielectric block 101 reach the metal layer 102, total internal reflection occurs, resulting in a current flowing through the surface of the metal layer 102. However, the metal layer 102 is a non-ideal conductor, and the current flowing through it incurs losses, leading to significant losses in the dielectric filter 10.

[0034] Therefore, to address the aforementioned problem of high loss in the dielectric filter 10, this application provides a dielectric filter. The described dielectric filter 10 can be applied in communication devices, such as 4G, 5G, or future sixth-generation mobile networks (6G) communication systems. The described dielectric filter 10 may include, but is not limited to, ceramic dielectric filters. In practical applications, the dielectric filter 10 can also be other filters capable of frequency selection for the antenna's transmit and receive signals; specific details are not limited in this application.

[0035] Figure 2A This is a cross-sectional schematic diagram of a dielectric filter provided in an embodiment of this application.

[0036] like Figure 2A As shown, the dielectric filter 10 includes a dielectric block 101, a dielectric layer 103, and a metal layer 102. The dielectric constant of the dielectric layer 103 is less than the dielectric constant of the dielectric block 101; wherein at least one surface of the dielectric block 101 is covered by the dielectric layer 103, and the surface of the dielectric layer 103 and the surface of the dielectric block 101 not covered by the dielectric layer 103 are covered by the metal layer 102.

[0037] In this example, at least one surface of the described medium block 101 is covered by the medium layer 103. This can be understood as the medium layer 103 covering at least one surface of the medium block 101, or not covering one or more surfaces of the medium block 101; that is, the medium layer 103 must cover at least one surface of the medium block 101. For example, if the medium block 101 is similar to a cuboid shape with 6 surfaces, then the medium layer 103 may cover only one surface of the medium block 101, or only two or three surfaces, etc.; or, the medium layer 103 may completely cover all six surfaces of the medium block 101. The specific number of surfaces of the medium block 101 covered by the medium layer 103 depends on the situation, and is not limited in this embodiment.

[0038] It should be noted that the above Figure 2A This diagram only shows two surfaces of the dielectric block covered by the dielectric layer. In practical applications, a diagram showing all surfaces of the dielectric block fully covered by the dielectric layer can also be found. Figure 2B To understand.

[0039] In addition, a metal layer can cover the surface of the dielectric layer 103, as well as the surface of the dielectric block 101 that is not covered by the dielectric layer 103.

[0040] In this embodiment, since the dielectric constant of the dielectric layer 103 is less than that of the dielectric block 101, when the dielectric constant of the dielectric block 101 is different from that of the dielectric layer 103 and the wave impedance, some of the electromagnetic waves propagating from the dielectric block 101 will be reflected after reaching the dielectric layer 103, so that the energy can be gradually reflected back. Therefore, less energy will reach the metal layer 102 in the end, resulting in less current loss on the surface of the metal layer 102, thereby effectively reducing the loss of the dielectric filter.

[0041] Figure 3A This is another cross-sectional schematic diagram of the dielectric filter provided in an embodiment of this application.

[0042] To facilitate understanding of this dielectric filter, in the above... Figure 2A Based on the dielectric filter shown, such as Figure 3A As shown, the dielectric layer includes N layers, with a K-layer dielectric layer covering the first surface of the dielectric block and a P-layer dielectric layer covering the second surface of the dielectric block. The first surface and the second surface are not the same, and the first surface and the second surface are one or more of at least one surface of the dielectric block. N is a positive integer, and K and P ≤ N.

[0043] In this example, the described first surface can be one or more of at least one surface of the medium block. For example, when the medium block has a cuboid-like shape with six surfaces, the first surface can be the top surface, or it can be composed of the top surface and the left side surface, etc., and this application does not impose a specific limitation. Similarly, the described second surface can be one or more of at least one surface of the medium block. For example, the second surface can be the bottom surface of the medium block, or it can be composed of the bottom surface and the surface of the front view, etc., and this application does not impose a specific limitation.

[0044] The K dielectric layers in the described N-layer dielectric layers 103 cover the first surface of the dielectric block 101. This can be understood as follows: the first dielectric layer 103K1 covers the outer surface of the first surface of the dielectric block 101; then the second dielectric layer 103K2 covers the outer surface of the first dielectric layer 103K1; the third dielectric layer covers the outer surface of the second dielectric layer 103K2; and so on, until the Kth dielectric layer 103KK covers the outer surface of the (K-1)th dielectric layer. Furthermore, the outer surface of the Kth dielectric layer 103KK can be covered by the metal layer 102. And the dielectric constant of each of the K dielectric layers 103 is less than the dielectric constant of the dielectric block 101.

[0045] Similarly, the P-layer dielectric layer in the described N-layer dielectric layer 103 covers the second surface of the dielectric block 101. This can be understood as follows: the first dielectric layer 103P1 in the P-layer dielectric layer 103 covers the outer surface of the second surface of the dielectric block 101; then the second dielectric layer 103P2 covers the outer surface of the first dielectric layer 103P1; the third dielectric layer covers the outer surface of the second dielectric layer 103P2; and so on, until the P-th dielectric layer 103PP covers the outer surface of the (P-1)-th dielectric layer. Furthermore, the outer surface of the P-th dielectric layer 103PP can be covered by the metal layer 102. And the dielectric constant of each dielectric layer 103 in the P-layer dielectric layer 103 is less than the dielectric constant of the dielectric block 101.

[0046] It should be understood that the above Figure 3A This diagram only shows the first surface (e.g., the left side) of the dielectric block being covered by the K-layer dielectric, and the second surface (e.g., the right side) being covered by the P-layer dielectric. For practical applications, a diagram showing all surfaces of the dielectric block fully covered by the dielectric layer can also be found. Figure 3B To understand.

[0047] It should be noted that K and P described above may be the same or different, and this application embodiment does not impose specific limitations. In this application embodiment, only the example of K and P being different is used for illustration.

[0048] The electromagnetic waves in the dielectric block 101 propagate from the first surface of the dielectric block 101 to the interface with the first dielectric layer 103K1. Due to the difference in dielectric constant and wave impedance between the dielectric block 101 and the first dielectric layer 103K1, part of the electromagnetic waves are reflected at the interface with the first dielectric layer 103K1, resulting in some energy being reflected back. Another part of the electromagnetic waves propagate to the first dielectric layer 103K1, allowing another portion of the energy to pass through the first dielectric layer 103K1 and propagate to the interface with the second dielectric layer 103K2, where some energy is reflected back. The remaining portion of the energy passes through the second dielectric layer 103K2 and reaches the interface between the second dielectric layer 103K2 and the third dielectric layer. Similarly, the energy propagating in the second surface of dielectric block 101 can also be reflected back after passing through the (K-1)th dielectric layer and reaching the boundary between the (K-1)th dielectric layer and the Kth dielectric layer 103KK. The remaining energy then passes through the Kth dielectric layer 103KK and reaches the metal layer 102, where it undergoes total internal reflection. Likewise, the propagation of electromagnetic waves in the second surface of dielectric block 101 can be similar to that in the first surface. Energy passes through the (P-1)th dielectric layer and reaches the boundary between the (P-1)th dielectric layer and the Pth dielectric layer 103PP, where it also reflects back. The remaining energy then passes through the Pth dielectric layer 103PP and reaches the metal layer 102, where it undergoes total internal reflection. Thus, the electromagnetic waves propagating from dielectric block 101 are reflected back after reaching each dielectric layer 103, gradually reducing the energy reflected back. Therefore, the energy reaching the metal layer 102 at the end is significantly less than the previously mentioned... Figure 1 The described conventional approach involves fewer currents, resulting in less current loss on the surface of the metal layer 102, thereby effectively reducing the loss of the dielectric filter 10.

[0049] It should be noted that the outer surface of the described Kth dielectric layer 103KK can be covered by the metal layer 102. This can also be understood as attaching a metal layer 102 to the outer surface of the Kth dielectric layer 103KK through electroplating, printing, welding, or spraying. Similarly, the outer surface of the described Pth dielectric layer 103PP can be covered by the metal layer 102. This can also be understood as attaching a metal layer 102 to the outer surface of the Pth dielectric layer 103PP through electroplating, printing, welding, or spraying. The metal layer 102 can confine electromagnetic waves within the dielectric block 101, preventing electromagnetic signal leakage. The material of the described metal layer 102 can be, but is not limited to, metals such as silver, copper, aluminum, titanium, tin, or gold.

[0050] In other examples, the dielectric constant of each of the N dielectric layers 103 may be the same or different, which is not limited here. Alternatively, the magnitude of the dielectric constant between each of the N dielectric layers 103 is not limited. For example, when a K dielectric layer 103 covers the first surface of the dielectric block 101, the dielectric constant of the first dielectric layer 103K1 may be greater than, less than, or equal to the dielectric constant of the second dielectric layer 103K2; or, the dielectric constant of the third dielectric layer may be greater than the dielectric constant of the second dielectric layer 103K2, and so on, without further limitation. The only requirement is that the dielectric constant of each of the N dielectric layers 103 is less than the dielectric constant of the dielectric block 101. The case where the P-layer dielectric layer 103 covers the second surface of the dielectric block 101 can also be understood by referring to the case where the K-layer dielectric layer 103 covers the first surface of the dielectric block 101, which will not be elaborated here.

[0051] For example, Figure 4A This illustration shows another cross-sectional view of the dielectric filter provided in an embodiment of this application. (See diagram below.) Figure 4A As shown, when N=1 and K=P=1, the dielectric filter 10 may include a dielectric block 101, a dielectric layer 103, and a metal layer 102. The dielectric constant of the dielectric layer 103 is less than that of the dielectric block 101. The dielectric layer 103 is attached to the outer surface of the dielectric block 101, and the metal layer 102 is attached to the outer surface of the dielectric layer 103. When electromagnetic waves propagate from the dielectric block 101 to the interface with the dielectric layer 103, due to the difference in dielectric constant and wave impedance between the dielectric block 101 and the dielectric layer 103, a portion of the electromagnetic waves are reflected at the interface, resulting in some energy being reflected back. Another portion of the electromagnetic waves propagates to the dielectric layer 103, and this remaining energy can pass through the dielectric layer 103 and propagate to the metal layer 102, where it undergoes total internal reflection. In this way, the electromagnetic waves propagating from the dielectric block 101 will be reflected after reaching the dielectric layer 103, allowing some of the energy to be gradually reflected back. Therefore, the energy that finally reaches the metal layer 102 is less than that mentioned above. Figure 1 The described conventional approach involves fewer currents, resulting in less current loss on the surface of the metal layer 102, thereby effectively reducing the loss of the dielectric filter 10.

[0052] You can also refer to Figure 4B This is another cross-sectional schematic diagram of the dielectric filter provided in an embodiment of this application. Figure 4BAs shown, when N=2, K=1, P=2, the dielectric filter 10 may include a dielectric block 101, two dielectric layers 103, and a metal layer 102.

[0053] In the first surface of the dielectric block 101, the dielectric layer 103 may include a first dielectric layer 103K1, which is attached to the outer side of the first surface of the dielectric block 101. In the second surface of the dielectric block 101, the dielectric layer 103 may include a first dielectric layer 103P1 and a second dielectric layer 103P2, with the first dielectric layer 103P1 attached to the outer side of the second surface of the dielectric block 101 and the second dielectric layer 103P2 attached to the outer surface of the first dielectric layer 103P1. Further, a metal layer 102 is attached to the outer surfaces of both the first dielectric layer 103K1 and the second dielectric layer 1032.

[0054] It should be noted that the dielectric constants of the first dielectric layer 103K1, the first dielectric layer 103P1, and the second dielectric layer 103P2 are all less than the dielectric constant of the dielectric block 101.

[0055] When the electromagnetic wave in the dielectric block 101 propagates from the first surface of the dielectric block 101 to the interface with the first dielectric layer 103K1, due to the difference in dielectric constant and wave impedance between the dielectric block 101 and the first dielectric layer 103K1, part of the electromagnetic wave is reflected at the interface between the dielectric block 101 and the first dielectric layer 103K1, so that part of the energy is reflected back, while another part passes through the first dielectric layer 103K1 and reaches the metal layer 102, where total internal reflection occurs. Similarly, when electromagnetic waves propagate from the second surface of dielectric block 101 to the interface with the first dielectric layer 103P1, due to the difference in dielectric constant and wave impedance between dielectric block 101 and the first dielectric layer 103P1, a portion of the electromagnetic waves are reflected at the interface, resulting in some energy being reflected back. Another portion of the electromagnetic waves can pass through the first dielectric layer 103P1 and propagate to the interface with the second dielectric layer 103P2, where some energy is reflected back. The remaining energy passes through the second dielectric layer 103P2 and reaches the metal layer 102, where total internal reflection occurs. Thus, the electromagnetic waves propagating from dielectric block 101 are reflected upon reaching each dielectric layer 103 in sequence, gradually reflecting energy back. Therefore, the energy reaching the metal layer 102 at the end is less than that described above. Figure 1 The described conventional approach involves fewer currents, resulting in less current loss on the surface of the metal layer 102, thereby effectively reducing the loss of the dielectric filter 10.

[0056] Similarly, in practical applications, three or four dielectric layers 103 can be superimposed on the surface of the dielectric block 101, but no specific limitation is made in this embodiment.

[0057] It should be noted that the above Figures 2A-4B The dielectric filter 10 shown is described only from a cross-sectional perspective. (Refer to...) Figure 5A This is a schematic diagram of one configuration of the dielectric filter 10 provided in an embodiment of this application. From... Figure 5A It can be seen that in the above Figures 2A-4B Based on any of the described dielectric filters 10, the surface of the dielectric block 101 may include at least one hole and / or at least one groove. The at least one hole or at least one groove may be symmetrically distributed based on the dielectric block 101.

[0058] In other examples, the surface of the medium block 101 can also be a flat plane, i.e., excluding... Figure 5A For details regarding the holes and / or grooves shown, please refer to [reference needed]. Figures 5B to 5C To understand this, we can refer to another schematic diagram of the dielectric filter 10. From... Figure 5B It can be seen that the surface of the medium block 101 has neither holes nor grooves. And from... Figure 5C It can be seen that there are no holes on the surface of the medium block 101.

[0059] in addition, Figures 5A to 5C The description uses a cuboid shape for the medium block 101 as an example. In practical applications, the medium block 101 can also be a cube, cylinder, elliptical cylinder, or other three-dimensional shape for easier processing and assembly. Of course, in practical applications, the medium block 101 can also be other shapes, such as cylindrical or trapezoidal. The specific shape is not limited in this application. The shape of the described hole can include, but is not limited to, circles, squares, and rhombuses. The shape of the described groove can also include, but is not limited to, cross-shaped grooves, straight grooves, and rectangular grooves. Furthermore, the number of holes or grooves is not limited in this embodiment.

[0060] It should be noted that the material of the dielectric block 101 described above can be a dielectric material with high dielectric constant and low loss, such as ceramics, etc., which will not be described here.

[0061] Furthermore, the material of the described dielectric filter 10 may include materials such as silicon oxide, boron oxide, calcium oxide, and / or aluminum oxide. In practical applications, the material of the dielectric filter 10 may also be other materials with low dielectric constant, low loss, and a temperature coefficient approaching zero, which can provide good dielectric performance for the dielectric filter 10.

[0062] Figure 6 This is a schematic diagram of a communication device provided in an embodiment of this application. Figure 6 As shown, the communication device may include a dielectric filter 10. The dielectric filter 10 can be coupled to an antenna for frequency selection of the antenna's transmit and receive signals. It should be noted that... Figure 6 The dielectric filter 10 in the above can be referred to the aforementioned Figures 2A-5C The dielectric filter 10 described herein will be understood, but its structure and working principle will not be elaborated here.

[0063] The described communication equipment may include, but is not limited to, base stations or terminals capable of 5G communication, or future base stations, satellite communication equipment or terminals capable of 6G communication. The described terminals may include, but are not limited to, at least one of the following: foldable electronic devices, tablet computers, desktop computers, laptop computers, handheld computers, laptops, ultra-mobile personal computers (UMPCs), netbooks, cellular phones, personal digital assistants (PDAs), augmented reality (AR) devices, virtual reality (VR) devices, artificial intelligence (AI) devices, wearable devices, in-vehicle devices, smart home devices, or smart city devices, without specific limitations.

[0064] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0065] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A dielectric filter, characterized in that, The dielectric filter includes a dielectric block, a dielectric layer, and a metal layer; The dielectric layer includes a first dielectric layer disposed on a first surface of the dielectric block, a second dielectric layer disposed on a second surface of the dielectric block, and a third dielectric layer, wherein the first surface and the second surface are different surfaces, and the third dielectric layer covers the outer surface of the second dielectric layer; The dielectric constants of the first dielectric layer, the second dielectric layer, and the third dielectric layer are all less than the dielectric constant of the dielectric block, and the dielectric constants of the second dielectric layer and the third dielectric layer are different. The metal layer covers the outer surface of the first dielectric layer, the outer surface of the third dielectric layer, and the surface of the dielectric block not covered by the dielectric layer.

2. The dielectric filter according to claim 1, characterized in that, The medium block is made of ceramic.

3. The dielectric filter according to claim 1 or 2, characterized in that, The materials of the dielectric filter include silicon oxide, boron oxide, calcium oxide, and / or aluminum oxide.

4. The dielectric filter according to claim 1 or 2, characterized in that, The surface of the medium block includes at least one hole and / or at least one groove.

5. The dielectric filter according to claim 1 or 2, characterized in that, The surface of the medium block does not include holes and / or grooves.

6. A communication device, characterized in that, The communication device includes a medium filter according to any one of claims 1-5.

Images