CN111384559A

CN111384559A - Dielectric filter, method for preparing dielectric filter and communication equipment

Info

Publication number: CN111384559A
Application number: CN201910217853.3A
Authority: CN
Inventors: 吴亚晖; 袁昕; 钟志波; 袁亮亮; 陆正武; 陈薛爱
Original assignee: Shenzhen Tatfook Technology Co Ltd
Current assignee: Shenzhen Tatfook Technology Co Ltd
Priority date: 2018-12-31
Filing date: 2019-03-21
Publication date: 2020-07-07

Abstract

The application discloses a dielectric filter, a method for preparing the dielectric filter and communication equipment. The dielectric filter of the embodiment of the application comprises at least two dielectric block combinations which are arranged side by side and at intervals and respectively comprise at least two dielectric blocks which are arranged in a coplanar manner and are arranged at intervals; the first medium coupling piece is arranged between at least two medium block combinations; a second dielectric coupling member disposed between at least two dielectric blocks of the same dielectric block combination disposed adjacent to each other in space to form a cross-coupling path; the dielectric filter comprises at least two dielectric block combinations, a first dielectric coupling piece and a second dielectric coupling piece, wherein the at least two dielectric block combinations, the first dielectric coupling piece and the second dielectric coupling piece are integrally sintered and molded, and the material of the dielectric filter at least comprises zinc oxide, silicon dioxide and magnesium oxide. By the mode, the production efficiency can be improved, the cost is saved, and the mass production is facilitated; and can reduce the volume while improving the characteristics such as out-of-band rejection.

Description

Dielectric filter, method for preparing dielectric filter and communication equipment

Technical Field

The present application relates to the field of communications technologies, and in particular, to a dielectric filter applied to a 5G communications system, a method for manufacturing the dielectric filter, and a communications device.

Background

With the rapid advance of communication technology, especially in the coming 5G communication era, more rigorous technical requirements are put on system architecture, and while high-efficiency and high-capacity communication is realized, system modules are required to be highly integrated, miniaturized, light-weighted and low-cost. For example, in the 5G Massive MIMO technology, when the system channel is expanded from the current 8 or 16 channels to 32, 64, or even 128 channels, the overall architecture size of the system cannot be too large, and even a certain degree of miniaturization needs to be realized. The microwave filter is used as a core component of a system, and performance parameters, size and cost of the microwave filter have great influence on the performance, architecture size and cost of the system.

The inventor of the present application finds, in long-term research and development work, that the dielectric filter has the characteristics of miniaturization and high performance, and receives more and more attention. The existing dielectric filters all adopt split splicing forming processes, complex and tedious processes such as steel mesh silver coating, high-precision positioning splicing of clamps, secondary high-temperature sintering and the like are needed in the processes, and the processes can cause low yield and low mass production efficiency of mass production of the dielectric filters, so that the production cost problem is prominent, and even the mass production is difficult.

Disclosure of Invention

The technical problem mainly solved by the present application is to provide a dielectric filter, a method for manufacturing the dielectric filter, and a communication device, so as to solve the above problems.

In order to solve the technical problem, the application adopts a technical scheme that: providing a dielectric filter, which comprises at least two dielectric block combinations, wherein the dielectric block combinations are arranged side by side and at intervals, and respectively comprise at least two dielectric blocks which are arranged in a coplanar manner and are at intervals; the first medium coupling piece is arranged between at least two medium block combinations and used for coupling different medium block combinations between two spatially adjacently arranged medium blocks so as to form a main coupling path which alternately passes through the medium blocks in the at least two medium block combinations; a second dielectric coupling member disposed between at least two dielectric blocks of the same dielectric block combination disposed adjacent to each other in space to form a cross-coupling path; the dielectric filter comprises at least two dielectric block combinations, a first dielectric coupling piece and a second dielectric coupling piece, wherein the at least two dielectric block combinations, the first dielectric coupling piece and the second dielectric coupling piece are integrally sintered and molded, and the material of the dielectric filter at least comprises zinc oxide, silicon dioxide and magnesium oxide.

In order to solve the above technical problem, the present application adopts another technical solution: there is provided a method for manufacturing a dielectric filter, for manufacturing the above dielectric filter, the method comprising:

providing raw materials corresponding to zinc oxide, silicon dioxide and magnesium oxide;

adding an organic solvent and grinding balls and carrying out primary ball milling;

drying the slurry obtained by the primary ball milling, and calcining to obtain a ceramic body;

crushing the ceramic body, adding an organic solvent and grinding balls, and performing secondary ball milling;

drying the slurry obtained by the secondary ball milling;

mixing the obtained powder with a binder to form slurry, and granulating;

dry-pressing and molding in a mold matched with the shape of the dielectric filter; and

removing the binder and sintering again to obtain at least two integrally sintered and molded medium block combinations, a first medium coupling piece and a second medium coupling piece;

and coating electromagnetic shielding layers on the outer surfaces of the at least two dielectric block combinations, the first dielectric coupling piece and the second dielectric coupling piece to obtain the dielectric filter.

In order to solve the above technical problem, the present application adopts another technical solution: the communication device comprises the dielectric filter and the antenna, wherein the dielectric filter is coupled with the antenna, and the dielectric filter is used for filtering the transceiving signals of the antenna.

The beneficial effect of this application is: different from the prior art, the dielectric filter in the embodiment of the application comprises at least two dielectric block combinations which are arranged side by side and at intervals and respectively comprise at least two dielectric blocks which are arranged in a coplanar manner and are arranged at intervals; the first medium coupling piece is arranged between at least two medium block combinations and used for coupling different medium block combinations between two spatially adjacently arranged medium blocks so as to form a main coupling path which alternately passes through the medium blocks in the at least two medium block combinations; a second dielectric coupling member disposed between at least two dielectric blocks of the same dielectric block combination disposed adjacent to each other in space to form a cross-coupling path; and the at least two medium block combinations, the first medium coupling piece and the second medium coupling piece are integrally sintered and molded. The dielectric block combination, the first dielectric coupling piece and the second dielectric coupling piece are integrally sintered and formed, so that the defects caused by complex and tedious processes such as steel mesh silver coating, high-precision positioning and splicing of a clamp, secondary high sintering and the like in the conventional dielectric filter sintering and forming process can be overcome, the production efficiency can be improved, the cost can be saved, and the mass production can be facilitated; meanwhile, the dielectric block combinations are arranged side by side, cross coupling among the non-cascaded dielectric resonance units is achieved through the second dielectric coupling pieces, transmission zero points can be achieved, out-of-band rejection and other characteristics are improved, and meanwhile the size is reduced. In addition, the material of the dielectric filter at least comprises zinc oxide, silicon dioxide and magnesium oxide, has low dielectric constant, low loss and near-zero temperature coefficient, and can improve the dielectric property of the dielectric filter.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of the structure of one embodiment of a dielectric filter;

FIG. 2 is a schematic 3D structure of a first embodiment of a dielectric filter of the present application;

FIG. 3 is a schematic diagram of the topology of the dielectric filter of the embodiment of FIG. 2;

FIG. 4 is a graph showing simulation results of the performance of the dielectric filter of the embodiment of FIG. 2;

FIG. 5 is a schematic of the topology of a second embodiment of the dielectric filter of the present application;

fig. 6 is a schematic 3D structure of a third embodiment of the dielectric filter of the present application;

FIG. 7 is a schematic diagram of the topology of the dielectric filter of the embodiment of FIG. 6;

FIG. 8 is a graph showing simulation results of the performance of the dielectric filter of the embodiment of FIG. 6;

FIG. 9 schematically shows the results of a test of the microwave dielectric properties of the ceramics provided herein;

fig. 10 is a schematic flow chart of a first embodiment of a method of manufacturing a dielectric filter according to the present application;

fig. 11 is a schematic structural diagram of an embodiment of the communication device of the present application.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be noted that the following examples are only illustrative of the present application, and do not limit the scope of the present application. Likewise, the following examples are only some examples and not all examples of the present application, and all other examples obtained by a person of ordinary skill in the art without any inventive step are within the scope of the present application.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The dielectric filter, the method for preparing the dielectric filter and the communication equipment can be used for a 5G communication system.

The dielectric filter is prepared by filling the resonant cavity with materials such as ceramics with high dielectric constants and the like, so that a microwave wavelength compression effect can be generated, the effective size of the resonant cavity can be greatly compressed, the overall size of the dielectric filter is miniaturized, and meanwhile, the materials such as ceramics are easy to mold, and batch production with lower cost can be realized, so that the dielectric filter is highly matched with the technical requirements of 5G micro base stations (Small Cells) and MIMO systems, and higher attention and market application of related communication scenes are obtained.

As shown in fig. 1, in order to realize a structure size as small as possible, a dielectric filter 101 is implemented by sintering a ceramic material into a plurality of required ceramic resonance modules, metallizing the surfaces of the ceramic resonance modules through a complicated process (no metallization is required at a coupling window), splicing and shaping the plurality of ceramic resonance modules by using a fixture, and sintering at a high temperature. The cascaded ceramic resonance modules realize signal coupling through the coupling windows, and the non-cascaded ceramic resonance modules realize cross coupling through the cross coupling modules.

However, the dielectric filter 101 is formed by a split splicing process, which requires complex and complicated processes such as steel mesh silver coating, high-precision positioning and splicing of a fixture, and secondary high-temperature sintering, and thus the dielectric filter 101 has poor performance stability and consistency during production, and the dielectric filter 101 has low yield and low mass production efficiency during mass production, which causes a significant production cost problem, and even is difficult to mass produce.

To solve the above problems, the present application first proposes a dielectric filter, as shown in fig. 2 and fig. 3, fig. 2 is a schematic 3D structure diagram of an embodiment of the dielectric filter of the present application; fig. 3 is a schematic diagram of the topology of the dielectric filter of the embodiment of fig. 2. The dielectric filter 201 of the present embodiment includes: the dielectric block combination comprises at least two

dielectric block combinations

202 and 203, a first dielectric coupling piece 204 and a second dielectric coupling piece 205, wherein the dielectric block combinations 202 and the dielectric block combinations 203 are arranged side by side and at intervals, the dielectric block combinations 202 comprise at least two dielectric blocks 206 which are arranged in a coplanar manner and are arranged at intervals, and the dielectric block combinations 203 comprise at least two dielectric blocks 207 which are arranged in a coplanar manner and are arranged at intervals; the first medium coupling piece 204 is arranged between the medium block combination 202 and the medium block combination 203, and the first medium coupling piece 204 is used for coupling the medium

resonant units

206 and 207 which are arranged on the medium block combination 202 and the medium block combination 203 in an adjacent space so as to form a main coupling path which alternately passes through at least the medium block combination 202 and the medium block combination 203; the second dielectric coupling piece 205 is disposed between at least two dielectric blocks 206 of the same dielectric block combination 202 that are disposed spatially adjacent to each other to form a cross-coupling path; the dielectric block combination 202, the dielectric block combination 203, the first dielectric coupling piece 204 and the second dielectric coupling piece 205 are integrally sintered and molded.

Specifically, the present embodiment may use a specific mold to form the dielectric block assembly 202, the dielectric block assembly 203, the first dielectric coupling piece 204, and the second dielectric coupling piece 205, and sinter-mold the dielectric block assembly 202, the dielectric block assembly 203, the first dielectric coupling piece 204, and the second dielectric coupling piece 205 at one time. The mold process can avoid complex surface metallization and positioning and clamping processes after molding, realize controllable dimensional precision, improve performance stability and have poor consistency.

Of course, in other embodiments, after the dielectric body is formed, a first groove and a plurality of second grooves may be formed on the dielectric body by grooving or etching, so as to form a dielectric block combination and a dielectric coupling member at intervals by the first groove, and form at least two dielectric blocks at intervals by the second groove, and then sinter-mold the dielectric blocks and the dielectric coupling member at one time.

In this embodiment, the dielectric block 206, the dielectric block 207, the first dielectric coupling member 204 and the second dielectric coupling member 205 are integrally formed by sintering the same dielectric material, which may be a ceramic material. In other embodiments, the material of the dielectric block and the dielectric coupling member may also be other materials with high dielectric constant and low loss, such as glass, quartz crystal, or titanate, and it is not limited whether the material of the dielectric block and the material of the dielectric coupling member are the same.

Different from the prior art, the dielectric block combination, the first dielectric coupling piece and the second dielectric coupling piece of the embodiment are integrally sintered and formed, so that the defects caused by complex and tedious processes such as steel mesh silver coating, high-precision positioning and splicing of a clamp, secondary high sintering and the like in the sintering and forming process of the conventional dielectric filter can be overcome, the production efficiency can be improved, the cost is saved, and the mass production is facilitated; meanwhile, the dielectric block combinations are arranged side by side, cross coupling among the non-cascaded dielectric resonance units is achieved through the second dielectric coupling pieces, transmission zero points can be achieved, out-of-band rejection and other characteristics are improved, and meanwhile the size is reduced.

Further, the dielectric filter 201 of the present embodiment further includes an electromagnetic shielding layer coated on the outer surfaces of the dielectric block assembly 202, the dielectric block assembly 203, the first dielectric coupling member 204, and the second dielectric coupling member 205. The electromagnetic shield layer is used to confine an electromagnetic field in the dielectric block assembly 202, the dielectric block assembly 203, the first dielectric coupling member 204, and the second dielectric coupling member 205, and can prevent leakage of an electromagnetic signal, so as to form a standing wave oscillation signal in the dielectric block assembly 202, the dielectric block assembly 203, the first dielectric coupling member 204, and the second dielectric coupling member 205, thereby realizing transmission of the electromagnetic signal.

The electromagnetic shielding layer of this embodiment may be a metal layer, and the metal layer may specifically cover the outer surfaces of the dielectric block assembly 202, the dielectric block assembly 203, the first dielectric coupling member 204, and the second dielectric coupling member 205 by plating, spraying, welding, or the like. The material of the metal layer may be silver, copper, aluminum, titanium, tin, gold, or the like.

Optionally, the surface of at least a part of the dielectric blocks 206 in the dielectric block assembly 202 of the present embodiment is overlapped with two of the dielectric blocks 207 in the dielectric block assembly 203 in a direction perpendicular to the horizontal direction, and the first dielectric coupling member 204 is formed in the overlapping region. That is, the partial dielectric block 206 can be coupled with the two dielectric blocks 207 through the plurality of first dielectric coupling pieces 204, respectively.

Specifically, the dielectric block 206 in the dielectric block assembly 202 and the dielectric block 207 in the dielectric block assembly 203 of the present embodiment are staggered from each other in the length direction, so that part of the dielectric block 206 overlaps with two dielectric blocks 207. Of course, in other embodiments, the shape and size of the dielectric block combination may be modified according to actual product and performance requirements.

Alternatively, the dielectric blocks 206 in the dielectric block combination 202 of the present embodiment, which are disposed to overlap with the two dielectric blocks 207 in the dielectric block combination 203, are dielectric blocks other than the dielectric block located at the end of the main transmission coupling path. That is, the dielectric block 206 at the non-end of the main transmission coupling path is overlapped with two dielectric blocks 207 in the dielectric block combination 203.

The dielectric block assembly 203 has a similar structure, which is not described herein.

Optionally, the first media coupling component 204 of the present embodiment is disposed in the gap between the combination of the media blocks 202 and the combination of the media blocks 203.

Optionally, the second media coupling piece 205 is disposed within a gap between an adjacently disposed dielectric block 206 and a dielectric block 207 to which it is coupled.

Further, the dielectric filter 201 of the present embodiment further includes an input terminal 208 and an output terminal 209, and the input terminal 208 and the output terminal 209 are respectively provided on the dielectric block 206 and the dielectric block 207 located at the end of the main coupling path.

Specifically, the input terminal 208 is provided on the dielectric block 207 within the dielectric block assembly 203 away from the dielectric block assembly 202; the output terminal 209 is disposed on the dielectric block 206 in the dielectric block assembly 202 away from the dielectric block assembly 203. Of course, in other embodiments, the positions of the input terminal and the output terminal may be reversed.

The axis of the input terminal 208 and the axis of the output terminal 209 are both perpendicular to the length direction of the dielectric block assembly 203.

Optionally, the dielectric blocks 206 in the dielectric block assembly 202 of the present embodiment are sequentially and cascade-connected along the length direction of the dielectric block assembly 202, the dielectric blocks 207 in the dielectric block assembly 203 are sequentially and cascade-connected along the length direction of the dielectric block assembly 203, and the dielectric block assembly 202 and the dielectric block assembly 203 are arranged side by side and at intervals perpendicular to the length direction.

In order to satisfy the performance of the dielectric block, the dielectric blocks 206 and 207 of the present embodiment have a large length and width and a relatively small height, and the dielectric blocks 206 and 207 are stacked in a direction perpendicular to the length direction (i.e., the height direction), so that the volume of the dielectric filter 201 can be reduced. Of course, in other embodiments, the two dielectric block combinations may also be stacked in the width direction.

Optionally, the number of the dielectric blocks 206 in the dielectric block combination 202 of the present embodiment is the same as the number of the dielectric blocks 207 in the dielectric block combination 203, and two of the dielectric blocks are disposed adjacent to each other.

Specifically, the number of the dielectric blocks 206 and the number of the dielectric blocks 207 in this embodiment are both 3.

The first media coupling piece 204 of the present embodiment can realize coupling between the cascaded (adjacent) dielectric block 206 and the dielectric block 207 in the main coupling path, and the second media coupling piece 205 is disposed between the dielectric block 206 (the dielectric block denoted by 2) and the dielectric block 207 (the dielectric block denoted by 4) to form a CT cross-coupling path, and can realize cross-coupling between the non-cascaded (non-adjacent) dielectric block 206 and the dielectric block 207 in the main coupling path, so that a cross-coupling path of the media filter 201 can be formed to generate a transmission zero, and improve performances of the media filter 201 such as out-of-band rejection, as shown in fig. 4, where the transmission zero is a dashed circle.

The transmission zero is the transmission function of the filter is equal to zero, namely, the electromagnetic energy cannot pass through the network on the frequency point corresponding to the transmission zero, so that the full isolation effect is achieved, the suppression effect on signals outside the passband is achieved, and the high isolation among the multiple passbands can be better achieved.

In other embodiments, the number of dielectric blocks in two dielectric combinations may be different, and the number and the stacking manner of the dielectric block combinations are not limited.

In other embodiments, other topological structures can be adopted among the plurality of dielectric blocks to realize various cross-coupling structures, so that the frequency selection performance of the filter is improved, and the out-of-band rejection performance and other performances are improved. For example, other topologies may be as shown in FIG. 5.

The present application further proposes a dielectric filter of a third embodiment, and as shown in fig. 6 and 7, a dielectric filter 601 of the present embodiment is different from the above-described dielectric filter in that: the first media coupling piece 602 of this embodiment is disposed between the media block assembly 603 and the media block assembly 604, and the first media coupling piece 602 is configured to couple the media block assembly 603 and the media block assembly 604 between the spatially

adjacent media blocks

605 and 606 to form a main coupling path; the second medium coupling piece 607 is disposed between the medium block combination 603 and the medium block combination 604, and the second medium coupling piece 607 is used for coupling the medium blocks 605 and 606 which are disposed adjacent to each other in space but not adjacent to each other along the main coupling path, so as to form a cross-coupling path.

The first medium coupling piece 602 couples the medium block 605 and the medium block 606 at the end of the

medium block combination

603 and 604 respectively; the second medium coupling piece 607 couples the other

medium blocks

605 and 606 than the

medium block

605 and 606 of the first medium coupling piece 602 and the second medium coupling piece 607 coupled by the first medium coupling piece 602.

Specifically, the dielectric block numbered 3 and the dielectric block numbered 4 are coupled by the first dielectric coupling element 602, and the dielectric block numbered 2 and the dielectric block numbered 5 are coupled and cross-coupled by the second dielectric coupling element 607 to form a CQ cross-coupling path, which can generate a pair of transmission zeros, as shown in fig. 8 (indicated by dashed circles), that is, a bottom transmission zero located on the left side of the frequency band and a high transmission zero located on the right side of the frequency band, and can further improve the out-of-band rejection performance of the dielectric filter 601.

The dielectric filter 201 of the present application is compared with the dielectric filter 601: the dielectric filter 601 with the CQ cross-coupling structure can generate one/more pairs of transmission zeros at two sides of a frequency band to improve the near-end out-of-band rejection of the dielectric filter 601, but the rejection improvement at a single side of the frequency band is not as good as that of the dielectric filter 201 with the CT cross-coupling structure, the transmission zeros of the dielectric filter 201 are controllable in position, and are not easy to interfere with out-of-band rejection or response, and meanwhile, the dielectric filter 201 does not require symmetry in structural arrangement, so that the flexibility in spatial distribution is higher.

In this embodiment, at least two dielectric blocks are combined and stacked to improve the near-end out-of-band rejection of the dielectric filter 601, and in another embodiment, at least two dielectric blocks may be combined and stacked to improve the far-end out-of-band rejection of the dielectric filter or disposed in the same layer.

The material of the dielectric filter disclosed in the above embodiment may be ceramic, and the ceramic includes zinc oxide, silicon dioxide, and magnesium oxide. I.e., the ceramic material consists essentially of the above-described components, it is understood that the ceramic may also contain small or trace amounts of other substances.

In some embodiments, the zinc oxide is present in a molar percentage of 20% to 70%.

In some embodiments, the silica is present in a mole percentage of 20% to 60%.

In some embodiments, the magnesium oxide is present in a molar percentage of 10% to 20%.

Wherein, mole percent refers to the percentage of the amount of the substance. For example, after mixing 1mol of substance a with 4mol of substance B, the molar percentage of substance a is equal to 1/(1+4) 20%, while the molar percentage of substance B is equal to 4/(1+4) 80%.

In some embodiments, the ceramic may further include a modifying additive, i.e., an additive capable of improving the properties of the ceramic. It should be understood that the modifying additive need not be in a liquid form, but may be in a solid form, etc. Specifically, the modifying additive may be CoO, NiO or MnO₂That is, the modifying additive may include only CoO, NiO, or MnO₂May also include two or three of them. Optionally, the proportion of the modifying additive can be 0-2 mol%. That is, the modifying additive is present in a molar percentage of no more than 2% of the total material.

The chemical composition of the ceramic can be expressed as xZnO-ySiO-zMgO₂dMO, wherein the ratio of x, y, z and d is 0.2-0.7: 0.2-0.6: 0.1-0.2: 0-0.02, MO represents the modifying additive. For example, if the values of x, y, z and d are taken as 0.5, 0.3, 0.18 and 0.02, respectively, and CoO is selected as a modifying additive, the chemical composition of the ceramic can be expressed as 0.5ZnO-0.3SiO-0.18MgO₂0.02 CoO. Of course, the values of x, y, z and d may take other values within this range. The microwave dielectric properties of the ceramic can be further adjusted by varying the proportions between the chemical components of the ceramic.

According to the test results, the dielectric constant of the ceramic is 7 to 8, and the Q f value is 9000 to 105000 GHz. The microwave dielectric properties of the ceramic were tested at a test frequency of 12GHz, for example, using a network analyzer (Agilent 5071C), resulting in test results as shown in the table in fig. 9.

The ceramics provided herein consist essentially of zinc oxide, silicon dioxide, and magnesium oxide, which have low dielectric constants, low losses, and near-zero temperature coefficients. Thus, the ceramics provided by the practice of the present application have improved microwave dielectric properties.

The present application further provides a method of manufacturing a dielectric filter according to a first embodiment, in which the dielectric filters disclosed in the above embodiments are manufactured by the method of manufacturing a dielectric filter, as shown in fig. 10, the method includes the steps of:

s801: raw materials corresponding to zinc oxide, silica and magnesium oxide are provided.

In some embodiments, the raw materials corresponding to zinc oxide, silica, and magnesium oxide may be oxides or carbonates of the corresponding metal elements. Wherein the oxide of the metal element directly corresponds to the component of the dielectric filter to be prepared, and some carbonates of the metal element can be converted into the oxide of the metal element under the condition of heating and the like, so that the carbonate can also be used as a raw material. In other embodiments, the starting material may also be an alcoholate of the corresponding metal element, in which case the alcoholate of the metal may be converted to the desired oxide using a suitable chemical treatment. The specific method is well known in the art and will not be described herein.

In this embodiment, the molar percentage of the raw material corresponding to zinc oxide is 20 to 70%, the molar percentage of the raw material corresponding to silicon dioxide is 20 to 60%, and the molar percentage of the raw material corresponding to magnesium oxide is 10 to 20%. It should be understood that the above mole percentages refer to mole percentages after removal of impurities in the raw materials.

In this embodiment, raw materials can be prepared in accordance with the proportions of the components of the dielectric filter. When the mole percentage of each component is known, the required mass of the raw material can be calculated according to parameters such as the molecular weight of each component, the purity of the raw material and the like. The mass required by each component is calculated according to the required mole number and molecular weight of each component, and the required mass of the raw material is calculated according to the required mass of each component and the purity of the raw material. This makes it possible to prepare raw materials of corresponding weights based on the results of the calculation.

In some embodiments, modifying additives may also be added to the raw materials. The modifying additive may be CoO, NiO or MnO₂One or more of the above. The modifying additive accounts for the total mole number of all raw materialsThe proportion of (B) should generally not exceed 2%.

S802: adding an organic solvent and grinding balls and carrying out primary ball milling.

In step S802, deionized water, alcohol, acetone, etc. may be used as the organic solvent, zirconium balls, agate balls, etc. may be used as the grinding balls, and ceramic, polyurethane, nylon, etc. may be used in the grinding tank, and planetary mill, stirring mill, tumbling mill, vibrating mill, etc. may be used for the first ball milling. Wherein, in order to improve the ball milling effect, proper dispersant can be added or the pH value of the slurry can be adjusted.

In some embodiments, deionized water may be used as the organic solvent, and ZrO may be used₂A grinding ball made of the material. In step S802, accurately weighed raw materials are poured into a ball mill pot, and deionized water and ZrO are added₂Grinding balls, wherein the weight ratio of the raw materials to the deionized water to the grinding balls is 1:1.5:4, and performing ball milling for 4 hours.

S803: and drying the slurry obtained by the primary ball milling, and calcining to obtain the ceramic body.

And (3) uniformly mixing the ball-milled materials, discharging and drying, for example, drying the materials at 100-120 ℃.

After the ball milling is finished and the mixture obtained after drying is required to be calcined at a certain temperature to synthesize the ceramic body, wherein the calcining temperature and the heat preservation time depend on the corresponding formula. For example, in this embodiment, the slurry dried after ball milling may be calcined at 900 to 1050 ℃ for 2 to 8 hours to synthesize a ceramic body.

S804: and (3) crushing the ceramic body, adding an organic solvent and grinding balls, and carrying out secondary ball milling.

The synthesized ceramic body is pulverized. The method of pulverization is not limited in the present application, and for example, it may be pulverized using a pulverizer. In some embodiments, the crushed ceramic body may also be sieved (e.g., 40 mesh).

And pouring the crushed ceramic body into the ball milling tank again for secondary ball milling, wherein the process of the secondary ball milling can be similar to that of the primary ball milling. For example, the ratio of the charge, milling balls and deionized water can be maintained constant and the milled ceramic body can be ball milled a second time for 24 hours. It should be understood that the process of the second ball milling may be different from the first ball milling, for example, the time of the second ball milling may be shorter (or longer) than that of the first ball milling, and is not limited herein.

S805: and drying the slurry obtained by secondary ball milling.

Similarly, the ball-milled materials can be uniformly mixed, discharged and dried. In some embodiments, the dried slurry may also be screened (e.g., through a 40 mesh screen).

S806: mixing the obtained powder with a binder to form slurry, and granulating.

In some embodiments, the binder may be a 5 wt% polyvinyl alcohol solution (i.e., the polyvinyl alcohol in the binder is 5 wt%). The binder may account for 15% of the total mass of the mixed slurry.

In some embodiments, the granulated powder may also be sieved (e.g., 40 mesh).

S807: and dry-pressing the dielectric filter in a mold matched with the shape of the dielectric filter.

Specifically, the granulated powder is put into a mold matching the shape of the dielectric filter, and is dry-pressed under a suitable pressure, for example, the powder may be dry-pressed under a pressure of 100 to 150 MPa.

In this step, the shape of the mold can be selected as desired, for example, if it is desired to perform a test, a mold dedicated for the test can be used to dry-press the powder into a shape

To facilitate testing. It should be understood that the shape and size of the mold can be arbitrarily selected according to the needs, and is not limited herein.

S808: and removing the bonding agent and sintering again to obtain at least two integrally sintered and molded medium block combinations, a first medium coupling piece and a second medium coupling piece.

The temperature may be selected to be a proper temperature for the heat preservation process, so as to remove the adhesive introduced in step S806, and then the two dielectric blocks are sintered again to finally obtain the desired integrally sintered at least two dielectric block combinations, the first dielectric coupling member and the second dielectric coupling member. Specifically, in this embodiment, the molded material may be heat-preserved at 400-700 ℃ (e.g., 500-600 ℃) for 2-10 hours, and then sintered at 1100-1250 ℃ for 2-10 hours (e.g., 2 hours at 1150 ℃). In this way, the adhesive added to the material in step S806 can be removed, and the at least two integrally sintered dielectric block combinations, the first dielectric coupling member, and the second dielectric coupling member in the desired shapes can be obtained.

S809: and coating electromagnetic shielding layers on the outer surfaces of the at least two dielectric block combinations, the first dielectric coupling piece and the second dielectric coupling piece to obtain the dielectric filter.

The electromagnetic shielding layer is the electromagnetic shielding layer disclosed in the above embodiments, and is not described herein again.

The present application further provides a communication device, as shown in fig. 11, the communication device 901 of this embodiment includes a dielectric filter 902 and an antenna 903, where the dielectric filter 902 is coupled to the antenna 903, and the dielectric filter 902 is used for filtering a transmission/reception signal of the antenna 903. The dielectric filter 902 of this embodiment is the dielectric filter of the above embodiment, and the structure and the operation principle thereof are not described herein again.

The communication device 901 may be a base station or a terminal for 5G communication, and the terminal may specifically be a mobile phone, a tablet computer, a wearable device with a 5G communication function, and the like.

Different from the prior art, the dielectric filter in the embodiment of the application comprises at least two dielectric block combinations which are arranged side by side and at intervals and respectively comprise at least two dielectric blocks which are arranged in a coplanar manner and are arranged at intervals; the first medium coupling piece is arranged between at least two medium block combinations and used for coupling different medium block combinations between two spatially adjacently arranged medium blocks so as to form a main coupling path which alternately passes through the medium blocks in the at least two medium block combinations; a second dielectric coupling member disposed between two dielectric blocks of the same dielectric block combination disposed adjacent to each other in space to form a cross-coupling path; and the at least two medium block combinations, the first medium coupling piece and the second medium coupling piece are integrally sintered and molded. The dielectric block combination, the first dielectric coupling piece and the second dielectric coupling piece are integrally sintered and formed, so that the defects caused by complex and tedious processes such as steel mesh silver coating, high-precision positioning and splicing of a clamp, secondary high sintering and the like in the conventional dielectric filter sintering and forming process can be overcome, the production efficiency can be improved, the cost can be saved, and the mass production can be facilitated; meanwhile, the dielectric block combinations are arranged side by side, cross coupling among the non-cascaded dielectric resonance units is achieved through the second dielectric coupling pieces, transmission zero points can be achieved, out-of-band rejection and other characteristics are improved, and meanwhile the size is reduced.

Furthermore, the dielectric filter in the embodiment of the application adopts evanescent mode coupling, so that the problems of precision and consistency caused by a window splicing process technology are solved.

Furthermore, the dielectric filter of the embodiment of the application can realize extremely high space utilization rate due to the symmetrical structure with regular appearance.

The position and the size of the dielectric resonance unit in the embodiment of the application are not limited to the above embodiment, and can be adjusted according to the actual electrical property of the dielectric filter; the number and topology of the dielectric resonance units in the embodiment of the present application are not limited to the above-described embodiments; the input terminal and the output terminal of the embodiment of the present application are not limited to the above-described positions; the input terminal and the output terminal of the embodiment of the application are not limited to the form of a probe, and can also be in the forms of a planar printed PCB (printed circuit board), a microstrip line and the like; in the cross-coupling topological structure of the embodiment of the application, the specific topological structure can be adjusted according to the actual electrical property requirement of the dielectric filter and the position requirements of the input terminal and the output terminal; the embodiment of the present application is not limited to the above-mentioned two-layer structure, and may be a structure with three or more layers.

It should be noted that the above embodiments belong to the same inventive concept, and the description of each embodiment has a different emphasis, and reference may be made to the description in other embodiments where the description in individual embodiments is not detailed.

The protection circuit and the control system provided by the embodiment of the present application are described in detail above, and a specific example is applied in the description to explain the principle and the embodiment of the present application, and the description of the above embodiment is only used to help understand the method and the core idea of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application or are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims

1. A dielectric filter, characterized in that the dielectric filter comprises:

the at least two dielectric block combinations are arranged at intervals and respectively comprise at least two dielectric blocks at intervals;

the first medium coupling piece is arranged between the at least two medium block combinations and used for coupling the two spatially adjacently arranged medium blocks of different medium block combinations so as to form a main coupling path which alternately passes through the medium blocks in the at least two medium block combinations;

the second medium coupling piece is arranged between at least two medium blocks which are arranged adjacently in space and combined by the same medium block so as to form a cross coupling path;

the at least two dielectric block combinations, the first dielectric coupling piece and the second dielectric coupling piece are integrally sintered and molded, and the material of the dielectric filter at least comprises zinc oxide, silicon dioxide and magnesium oxide.

2. The dielectric filter of claim 1, wherein the zinc oxide is 20-70 mol%, the silicon dioxide is 20-60 mol%, and the magnesium oxide is 10-20 mol%.

3. The dielectric filter according to claim 1, wherein at least some of the dielectric blocks in at least some of the dielectric block combinations have surfaces overlapping with two of the other dielectric block combinations in a length direction, and the first dielectric coupling member is formed in an overlapping region, and the at least some of the dielectric blocks are dielectric blocks other than the dielectric block at an end of the main coupling path;

the dielectric filter further includes an input terminal and an output terminal which are respectively provided on the two dielectric blocks located at the end portions of the main transmission path.

4. The dielectric filter of claim 3, wherein the dielectric blocks in the at least two dielectric block combinations are respectively arranged at intervals along a length direction of the dielectric block combinations, and the at least two dielectric block combinations are arranged side by side and at intervals perpendicular to the length direction, and the dielectric blocks in the at least two dielectric block combinations are staggered from each other along the length direction.

5. The dielectric filter of claim 1, wherein the second dielectric coupling is to form a CT cross-coupling path;

the first medium coupling piece is arranged in a gap between the at least two medium block combinations, and the second medium coupling piece is arranged in a gap between the two adjacent medium blocks coupled by the second medium coupling piece.

6. The dielectric filter of claim 1, further comprising an electromagnetic shield layer coated on an outer surface of the at least two dielectric block combinations, the first dielectric coupling component, and the second dielectric coupling component.

7. The dielectric filter of claim 1, wherein the two dielectric block combinations, the first dielectric coupling member, and the second dielectric coupling member are integrally sintered from the same dielectric material.

8. The dielectric filter of claim 1, wherein the material of the dielectric filter further comprises a modifying additive, the modifying additive is 0-2 mol%, and the modifying additive is CoO, NiO or MnO₂A combination of one or more of;

the chemical composition of the material of the dielectric filter is xZnO-ySiO-zMgO₂dMO, wherein the ratio of x, y, z and d is 0.2-0.7: 0.2-0.6: 0.1-0.2: 0-0.02, MO represents the modifying additive, and the dielectric constant of the material of the dielectric filter is 7-8.

9. A method of manufacturing a dielectric filter, the method being used to manufacture a dielectric filter according to any one of claims 1 to 8, the method comprising:

drying the slurry obtained by the secondary ball milling;

mixing the obtained powder with a binder to form slurry, and granulating;

10. A communication device, comprising the dielectric filter according to any one of claims 1 to 8 and an antenna, wherein the dielectric filter is coupled to the antenna, and wherein the dielectric filter is configured to filter a transceived signal of the antenna.