CN111384531A

CN111384531A - Dielectric filter, communication equipment, method for preparing dielectric block and dielectric filter

Info

Publication number: CN111384531A
Application number: CN201910218534.4A
Authority: CN
Inventors: 袁亮亮; 陆正武; 陈薛爱; 吴文敬; 钟志波
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, communication equipment, a dielectric block and a method for manufacturing the dielectric filter. The dielectric filter includes: the dielectric block forms at least two resonant cavities which are connected; the first coupling hole is arranged on a first surface of the dielectric block, the second coupling hole is arranged on a second surface of the dielectric block, and the first surface and the second surface are arranged oppositely; the metal layer covers the surface of the dielectric block, the surface of the first coupling hole and the surface of the second coupling hole; wherein, the material of the dielectric filter at least comprises magnesium oxide, calcium oxide, titanium dioxide and zinc oxide. By the method, the precision of debugging the transmission zero point can be improved; and the dielectric filter has low dielectric constant, low loss and near-zero temperature coefficient, and can improve the dielectric property of the dielectric filter.

Description

Dielectric filter, communication equipment, method for preparing dielectric block and dielectric filter

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 communications device, a method for manufacturing a dielectric block, and a method for manufacturing a dielectric filter.

Background

In a mobile communication system, a desired signal is modulated to form a modulated signal, the modulated signal is carried on a high-frequency carrier signal, the modulated signal is transmitted to the air through a transmitting antenna, the signal in the air is received through a receiving antenna, and the signal received by the receiving antenna does not include the desired signal but also includes harmonics and noise signals of other frequencies. The signal received by the receiving antenna needs to be filtered by a dielectric filter to remove unnecessary harmonic wave and noise signals.

With the rapid advance of communication technology, especially in the 5G communication era, more severe technical requirements are put on the filter, and the filter is required to have the characteristics of miniaturization, high performance and the like.

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. In order to improve the out-of-band rejection and other performances of the dielectric filter, a coupling hole is usually arranged on the dielectric block, and a transmission zero point is realized through the coupling hole, but the debugging precision of the coupling hole in the existing dielectric filter to the transmission zero point is not high.

Disclosure of Invention

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

In order to solve the technical problem, the application adopts a technical scheme that: there is provided a dielectric filter including: the dielectric block forms at least two resonant cavities which are connected; the first coupling hole is arranged on a first surface of the dielectric block, the second coupling hole is arranged on a second surface of the dielectric block, and the first surface and the second surface are arranged oppositely; the metal layer covers the surface of the dielectric block, the surface of the first coupling hole and the surface of the second coupling hole; wherein, the material of the dielectric filter at least comprises magnesium oxide, calcium oxide, titanium dioxide and zinc oxide.

In order to solve the technical problem, the present application adopts a technical scheme that: there is provided a method of preparing a dielectric block, the method for preparing the above dielectric block, the method comprising: providing raw materials corresponding to magnesium oxide, calcium oxide, titanium dioxide and zinc 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 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 block; and removing the binder and sintering again to obtain the dielectric block.

In order to solve the technical problem, the present application adopts a technical scheme that: there is provided a method for manufacturing a dielectric filter, the method being used for manufacturing the above dielectric filter, the method comprising: providing a dielectric block, wherein the dielectric block is prepared by the method; and covering a metal layer on the surface of the dielectric block to obtain the dielectric filter.

In order to solve the above technical problem, another technical solution adopted by the present application is: there is provided a communication device comprising an antenna and a dielectric filter as described above, the antenna being coupled to the dielectric filter.

The beneficial effect of this application is: different from the prior art, the dielectric filter provided by the embodiment of the application adjusts the transmission zero point by arranging at least two coupling holes, and can weaken the sensitivity of each coupling hole to the transmission zero point, so that the debugging precision of the transmission zero point can be improved; in addition, the material of the dielectric filter at least comprises magnesium oxide, calcium oxide, titanium dioxide and zinc 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 structural diagram of a first embodiment of a dielectric filter according to the present application;

FIG. 2 is a schematic structural diagram of a second embodiment of a dielectric filter according to the present application;

FIG. 3 is a schematic structural diagram of a third embodiment of a dielectric filter according to the present application;

FIG. 4 is a schematic structural diagram of a fourth embodiment of a dielectric filter according to the present application;

fig. 5 is a schematic structural view of a fifth embodiment of the dielectric filter of the present application;

fig. 6 is a schematic structural diagram of a sixth embodiment of a dielectric filter according to the present application;

FIG. 7 is a schematic flow chart diagram illustrating one embodiment of a method for forming a dielectric block according to the present application;

FIG. 8 is a schematic flow chart diagram illustrating one embodiment of a method for making a dielectric filter according to the present application;

FIG. 9 is a schematic block diagram of an embodiment of a communication device of the present application;

fig. 10 is a schematic flowchart of a first embodiment of a method for tuning a dielectric filter according to the present application;

fig. 11 is a flowchart illustrating a second embodiment of a method for tuning a dielectric filter according to 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 resonator, the dielectric filter and the communication equipment can be used for 5G communication.

The present application first proposes a dielectric filter, as shown in fig. 1, and fig. 1 is a schematic structural diagram of a first embodiment of the dielectric filter of the present application. The dielectric filter 101 of the present embodiment includes: the dielectric block 102, at least a first coupling hole 103, a second coupling hole 104 and a metal layer 105, wherein the dielectric block 102 forms at least two

resonant cavities

106 and 107, and the resonant cavity 106 is connected with the resonant cavity 107; the first coupling hole 103 is provided on a first surface of the dielectric block 102, and the second coupling hole 104 is provided on a second surface of the dielectric block 102, the first surface being disposed opposite to the second surface; the metal layer 105 covers the surface of the dielectric block 102, the surface of the first coupling hole 103, and the surface of the second coupling hole 104.

In this embodiment, the dielectric resonator 106 and the metal layer 105 covering the surface thereof form a first dielectric resonator, and the dielectric resonator 107 and the metal layer 105 covering the surface thereof form a second dielectric resonator. The dielectric filter 101 is composed of a first dielectric resonator and a second dielectric resonator.

Specifically, at least the first coupling hole 103 and the second coupling hole 104 of the present embodiment are disposed on two opposite surfaces of the joint of the first dielectric resonator and the second dielectric resonator. Since the coupling hole is provided between the first dielectric resonator and the second dielectric resonator, the dielectric structure at the joint (i.e., the coupling bridge) between the first resonator and the second resonator is changed, and the coupling polarity of the electromagnetic field between the first resonator and the second resonator is changed, so that the transmission zero point of the dielectric filter 101 can be realized.

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 this embodiment, the first coupling hole 103 and the second coupling hole 104 are respectively disposed on two opposite surfaces of the connection portion of the first resonator and the second resonator, so that the sensitivity of each coupling hole to the transmission zero point can be reduced.

Among them, the metal layer 103 serves to confine an electromagnetic field within the dielectric block 102, and can prevent an electromagnetic signal from leaking to form a standing wave oscillation signal within the dielectric block 102. The metal layer 103 may be coated on the surface of the dielectric block 102 by plating, spraying, or welding.

The dielectric block 102 of this embodiment is a dielectric block made of a solid dielectric material, which may be a ceramic material. In other embodiments, the material of the dielectric block may also be other materials with high dielectric constant and low loss, such as glass, quartz crystal, or titanate.

Different from the prior art, the dielectric filter 101 of the embodiment adjusts the transmission zero point by arranging at least two coupling holes, and can weaken the sensitivity of each coupling hole to the transmission zero point, thereby improving the precision of transmission zero point debugging.

Optionally, the first size data of the first coupling hole 103 of the present embodiment is different from the second size data of the second coupling hole 104. Since the frequency of the transmission zero of the dielectric filter is related to the size data of the coupling hole, the first coupling hole 103 and the second coupling hole 104 having different size data can realize different sensitivities to the transmission zero, so as to improve the precision of the transmission zero debugging.

Specifically, in an embodiment, as shown in fig. 2, fig. 2 is a schematic structural diagram of a second embodiment of the dielectric filter of the present application. The ratio of the depth of the first coupling hole 202 to the depth of the second coupling hole 203 of the dielectric filter 201 of the present embodiment may be in the range of 0.8 to 1.2. The ratio may be specifically 0.8, 1, 1.2, etc.

The coupling between the dielectric resonators may be divided into positive coupling (i.e., inductive coupling) capable of generating a high-end transmission zero in the frequency band of the dielectric filter and negative coupling (i.e., capacitive coupling) capable of generating a low-end transmission zero in the frequency band of the dielectric filter according to the polarity.

Optionally, to realize the negative coupling between the first resonator 204 and the second resonator 205 to realize the transmission zero of the dielectric filter 201, a ratio of the depth of the first coupling hole 202 to the depth of the second coupling hole 203 may range from 1 to 1.2, and the depths may specifically be 1, 1.1, 1.2, and the like.

Alternatively, to realize positive coupling between the first resonator 204 and the second resonator 205, the ratio of the depth of the first coupling hole 202 to the depth of the second coupling hole 203 may range from 0.8 to 1, and the depth ratio may specifically be 0.8, 0.9, 1, and so on.

The frequency of the transmission zero is related to the size data of the coupling hole, and in another embodiment, the ratio of the depth of the first coupling hole to the radius of the first coupling hole is in the range of 0.9-1.1, and the ratio may be specifically 0.9-1, 1.1, and the like.

In another embodiment, as shown in fig. 4, the thickness of the metal layer disposed in the first coupling hole 401 is greater than the thickness of the metal layer disposed in the second coupling hole 402.

Specifically, after the first coupling hole 401 and the second coupling hole 402 are formed in the dielectric block 403, a metal layer 404 is uniformly formed on the surface of the dielectric block 403 and the inner surfaces of the first coupling hole 401 and the second coupling hole 402, and then metal is coated on the metal layer in the first coupling hole 401 according to actual debugging requirements to increase the metal layer in the first coupling hole 401 and/or polish the metal layer in the second coupling hole 402 to thin the metal layer in the second coupling hole 402.

In other embodiments, the size data of the coupling hole is not limited to the cross-sectional area, depth, cross-sectional shape, etc. of the coupling hole. It should be noted that, the present application does not limit that only one size parameter of the first coupling hole and the second coupling hole is different, and the coupling holes with two or more different size data may be disposed on the dielectric block according to the actual product and application requirements.

Optionally, with continued reference to fig. 1, for simplicity, the axes of the first coupling hole 103 and the second coupling hole 104 are perpendicular to the first surface of the dielectric block 102. Of course, in other embodiments, the axis of the first coupling hole and/or the axis of the second coupling hole may also be non-perpendicular to the first surface of the dielectric block.

Alternatively, the first coupling hole 103 and the second coupling hole 104 of the present embodiment are coaxially disposed.

Optionally, with reference to fig. 1, the dielectric filter 101 of the present embodiment further includes a first blind via 108 and a second blind via 109, the first resonant cavity 106 is provided with the first blind via 108, and the second resonant cavity 107 is provided with the second blind via 109.

The first blind hole 108 and the second blind hole 109 of the present embodiment are disposed on the same surface of the dielectric block 102, and the central axis of the first blind hole 108, the central axis of the second blind hole 109, and the central axis of the first coupling hole 103 are parallel to each other, so as to simplify the process.

In other embodiments, any two of the three axes described above in the above embodiments may form an acute angle.

The first blind hole 108 of the present embodiment is used for adjusting a first parameter of a first dielectric resonator (corresponding to the resonant cavity 106) to adjust a first parameter of the dielectric filter 101; the second blind via 109 is used to adjust a second parameter of a second dielectric resonator (corresponding to the resonant cavity 107) to adjust a second parameter of the dielectric filter 101.

The first parameter of this embodiment may be the same as the first parameter, and the first parameter may be the resonant frequency of the dielectric resonator 101.

Of course, in other embodiments, the first parameter may also be different from the second parameter.

The blind holes are arranged on the dielectric block 102, so that the dielectric structure of the dielectric block 102 is changed, and the change of the structure of the dielectric block 102 can cause the distribution of the electromagnetic field in the dielectric filter 101 to change, so that the parameters of the electromagnetic field in the dielectric filter 101 are changed.

The present application further proposes a schematic structural diagram of a dielectric filter of a fifth embodiment, and as shown in fig. 5, a dielectric filter 501 of this embodiment is different from the dielectric filter 101 described above in that: the first dielectric resonator 502 of this embodiment is provided with a first blind via 504 and a second blind via 505, and can perform coarse adjustment on the first parameter of the first dielectric resonator 502 through the first blind via 504 to perform coarse adjustment on the first parameter of the dielectric filter 101, and perform fine adjustment on the first parameter of the first dielectric resonator 502 through the second blind via 505 to perform fine adjustment on the second parameter of the dielectric filter 501.

Wherein, the size data of the first blind hole 504 is different from the size data of the second blind hole 505.

In this embodiment, two blind holes are disposed in the second dielectric resonator 503 to perform coarse tuning and fine tuning on the second parameter of the second dielectric resonator 503, respectively.

Different from the prior art, in the embodiment, the blind holes with different size data are arranged on one dielectric resonator, so that the rough adjustment and the fine adjustment of the parameters can be realized, and the adjustment accuracy of the parameters can be improved.

Optionally, the depth of the first blind hole 504 of the present embodiment is greater than the depth of the second blind hole 505.

The deeper the blind holes formed in the dielectric block are, the greater the influence of the blind holes on the electromagnetic distribution in the dielectric resonator and in the dielectric filter composed of the dielectric resonator is, and therefore, the blind holes with different depths can be used for adjusting different parameters of the dielectric filter 501 or different ranges of the same parameter.

In another embodiment, the cross-sectional area of the first blind via is larger than the cross-sectional area of the second blind via in the same dielectric resonator.

In another embodiment, in order to make the first blind hole and the second blind hole have different influences on the electromagnetic distribution in the dielectric resonator and the dielectric filter composed of the dielectric resonator, the thickness of the metal layer in the first blind hole may be set to be larger than the thickness of the metal layer in the second blind hole.

In other embodiments, the dimension data of the blind hole is not limited to the cross-sectional area, depth, cross-sectional shape, etc. of the blind hole. It should be noted that, the first blind via and the second blind via are not limited to have only one size data different in the present application, and two or more blind vias having different size data may be disposed on the dielectric block according to the actual product and application requirements.

The first blind via 504 and the second blind via 505 of the present embodiment are provided on the same surface of the second dielectric resonator 502. The arrangement mode simplifies the production of the blind hole and is convenient for debugging. In another embodiment, the first blind via and the second blind via can be disposed on two opposite surfaces of the dielectric block.

The axis of the first blind hole 504 of the present embodiment is parallel to the axis of the second blind hole 505, which facilitates the blind hole process. In another embodiment, the axis of the first blind hole is at an acute angle to the axis of the second blind hole.

In the above embodiments of the present application, the cross-sectional shapes of the coupling hole and the blind hole are both circular. Of course, in other embodiments, the coupling hole and the blind hole may also be square or diamond, and the like, and it is not limited whether the coupling hole and the blind hole have the same cross-sectional shape.

The connecting part between the adjacent dielectric resonators can be provided with two or more coupling holes, and whether the number of the coupling holes at each connecting part is the same or not is not limited; one, two or more than two blind holes can be arranged on one dielectric resonator, and whether the number of the blind holes arranged on each dielectric resonator is the same or not is not limited; the present application does not limit whether the dimensional data of the blind holes on each dielectric resonator is the same.

The arrangement positions of a plurality of coupling holes and blind holes on the same surface are not limited.

When the dielectric resonator and the dielectric filter composed of the dielectric resonator are debugged through at least the first coupling hole and the second coupling hole, one mode is that the parameters are adjusted by polishing/laying the metal layers in the first coupling hole and the second coupling hole; in another mode, the parameters of the dielectric resonator or the dielectric filter are adjusted by adjusting the depth of the adjusting nut in the first coupling hole and the second coupling hole by penetrating the adjusting screw into the first coupling hole and the second coupling hole.

To this end, the present application further proposes a dielectric filter of a sixth embodiment, and as shown in fig. 6, a dielectric filter 601 of this embodiment is different from the above-described embodiments in that: the dielectric filter 601 of this embodiment further includes a first adjusting screw 602 and a second adjusting screw 603, the first adjusting screw 602 is disposed in the first coupling hole 604, the second adjusting screw 603 is disposed in the second coupling hole 605, no metal layer is disposed in the first coupling hole 604 and the second coupling hole 605, the electromagnetic field distribution in the dielectric filter 601 is changed by adjusting the depth of the first adjusting screw 602 in the first coupling hole 604, so as to implement adjustment of the transmission zero point, and the electromagnetic field distribution in the dielectric filter 601 is changed by adjusting the depth of the second adjusting screw 603 in the second coupling hole 605, so as to implement adjustment of the transmission zero point.

To avoid signal leakage, the gap between the first adjusting screw 602 and the first coupling hole 604 is smaller than a predetermined value to shield the electromagnetic signal in the dielectric block, and the gap between the second adjusting screw 603 and the second coupling hole 605 is smaller than a predetermined value to shield the electromagnetic signal in the dielectric block.

The dielectric blocks of the at least two dielectric filters are integrally formed, so that the problems of signal leakage, process complexity, process deviation and the like caused by a splicing process can be reduced.

In another embodiment, an adjusting screw rod can be arranged in the blind hole to adjust parameters such as the resonant frequency of the dielectric filter.

The material of the dielectric filter disclosed in the above embodiment may be ceramic, which includes magnesium oxide, calcium oxide, titanium dioxide, and zinc oxide. I.e., the ceramic 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 magnesium oxide is present in a molar percentage of 20% to 30%.

In some embodiments, the calcium oxide is present in a molar percentage of 2% to 10%.

In some embodiments, the titanium dioxide comprises 50 to 75 mole percent thereof.

In some embodiments, the zinc oxide is present in an amount of 0.1 to 5 mole percent.

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%.

The chemical composition of the ceramic can be expressed as aMgO-bCaO-cTiO₂-dZnO, wherein the ratio of a, b, c and d is 0.2-0.3: 0.02-0.1: 0.5-0.7: 0.001-0.05. For example, if the values of a, b, c and d are taken as 0.2, 0.1, 0.65 and 0.05, respectively, the chemical composition of the ceramic may be expressed as 0.2MgO-0.1CaO-0.65TiO₂-0.05 ZnO. Of course, the values of a, b, c and d may take other values within this range. The microwave dielectric property of the ceramic can be further adjusted by changing the proportion of the chemical components of the ceramic。

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 a combination of one or more of oxides of Si, Cu, or Ni, that is, the modifying additive may include only one of the oxides of Si, Cu, or Ni, or may include two or three thereof. Optionally, the proportion of the modifying additive can be 0-2 wt%. That is, the modifying additive is present in an amount of no more than 2% by weight of the total material.

According to the test result, the dielectric constant of the ceramic is 18-22, and the Q f value is larger than 80000 GHz. For example, the microwave dielectric property of the ceramic is tested by a network analyzer (Agilent 5071C) at a test frequency of 4.7GHz, and the microwave dielectric property of the ceramic is obtained as follows: the dielectric constant r is 20.6, the dielectric loss Q f is 83000GHz, and the temperature coefficient f is-2 ppm/° c.

The ceramic provided by the application mainly comprises magnesium oxide, calcium oxide, titanium dioxide and zinc oxide, and has low dielectric constant, low loss and near-zero temperature coefficient. Thus, the ceramics provided by the practice of the present application have improved dielectric properties of dielectric filters.

The present application further provides a method for manufacturing a dielectric block, in which the dielectric block disclosed in the above embodiments is manufactured by the method for manufacturing a dielectric block, as shown in fig. 7, the method for manufacturing a dielectric block includes the following steps:

s701: raw materials corresponding to magnesium oxide, calcium oxide, titanium dioxide and zinc oxide are provided.

In some embodiments, the raw materials corresponding to magnesium oxide, calcium oxide, titanium dioxide, and zinc oxide may be oxides or carbonates of the corresponding metal elements. Wherein the oxides of the metal elements directly correspond to the components of the dielectric block to be produced, while carbonates of some metal elements can be converted into oxides of the metal elements under the conditions of heating and the like, and thus can also be used as raw materials. 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 magnesium oxide is 20 to 30%, the molar percentage of the raw material corresponding to calcium oxide is 2 to 10%, the molar percentage of the raw material corresponding to titanium dioxide is 50 to 75%, and the molar percentage of the raw material corresponding to zinc oxide is 0.1 to 5%. 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 may be prepared in accordance with the proportions of the components of the dielectric block. 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. For example, 97 wt% of MgO and 99.8 wt% of CaCO can be used₃And TiO₂And 99.5 wt% of ZnO, calculating the mass required by each component according to the required mole number and molecular weight of each component, and calculating the mass of the required raw material according to the mass required by 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 one or more of oxides of Si, Cu or Ni. The modifying additive should generally not exceed 2% by weight of the total weight of all raw materials.

S702: adding an organic solvent and grinding balls and carrying out primary ball milling.

In step S702, 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, alcohol may be used as the organic solvent, and ZrO may be used₂MaterialAnd (5) preparing the grinding ball. In step S702, accurately weighed raw materials are poured into a ball mill pot, and alcohol and ZrO are added₂Grinding balls, wherein the weight ratio of the raw materials to the grinding balls to the alcohol is 1:2:1.5, and performing ball milling for 24 hours.

S703: 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 1100 ℃ for 12 hours to synthesize a ceramic body.

S704: 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 pulverized ceramic body may be ball milled for a second time for 24 hours while maintaining the ratio of the material, alcohol and grinding balls constant. 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.

S705: 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).

S706: mixing the obtained powder with a binder to form slurry, and granulating.

In some embodiments, the binder may be a 10 wt% polyvinyl alcohol solution (i.e., the polyvinyl alcohol in the binder is 10 wt%).

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

S707: and (4) carrying out dry pressing forming in a die matched with the shape of the medium block.

Specifically, the granulated powder is placed in a mold matching the shape of the dielectric block, 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 other embodiments, the shape of the mold may be selected as desired, for example, if testing is desired, a test-specific mold may be used to dry-press the powder into a phi 12 × 6mm disk for ease of testing.

S708: the binder is removed and sintered again to obtain the dielectric block.

The temperature may be selected to be a suitable temperature for the soaking process to remove the binder introduced in step S706, and then sintered again to finally obtain the desired dielectric block. Specifically, in this embodiment, the molded material may be heat-preserved at 600 ℃ for 2 hours, and then sintered at 1150-1400 ℃ for 2-24 hours. In this way, the adhesive added to the material in step S706 can be removed and a dielectric block of a desired shape can be obtained.

The present application further provides a method for manufacturing a dielectric filter according to a first embodiment, in which the dielectric filter disclosed in the above embodiment is manufactured by the method for manufacturing a dielectric filter, as shown in fig. 8, the method includes the following steps:

s801: a dielectric block is provided.

The dielectric block is prepared by the above-described method of preparing a dielectric block, i.e., the dielectric block prepared by the above-described steps S701 to S708. The shape of the dielectric block is the same as the preset shape of the dielectric filter.

S802: and covering a metal layer on the surface of the dielectric block to obtain the dielectric filter.

The surface of the dielectric block is covered with a metal layer, so that an electromagnetic field is limited in the dielectric block, and the electromagnetic signal is prevented from leaking. The metal layer may be made of silver, copper, aluminum, titanium, tin or gold, and the metal layer may be coated on the surface of the dielectric block by electroplating, spraying or welding.

The present application further provides a communication device, as shown in fig. 9, fig. 9 is a schematic structural diagram of an embodiment of the communication device of the present application. The communication device 901 of this embodiment includes an antenna 902 and a dielectric filter 903, where the antenna 902 is coupled to the dielectric filter 903, the antenna 902 is used for transceiving a radio frequency signal, and the dielectric filter 903 is used for filtering the radio frequency signal to filter out noise.

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 of the embodiment of the present application includes: the dielectric block forms at least two resonant cavities which are connected; the first coupling hole is arranged on a first surface of the dielectric block, the second coupling hole is arranged on a second surface of the dielectric block, and the first surface and the second surface are arranged oppositely; and the metal layer covers the surface of the dielectric block, the surface of the first coupling hole and the surface of the second coupling hole. According to the dielectric filter, the transmission zero point is adjusted by arranging the at least two coupling holes, the sensitivity of each coupling hole to the transmission zero point can be weakened, and therefore the accuracy of transmission zero point debugging can be improved.

The application further provides a debugging method of the dielectric resonator, which is used for debugging the dielectric resonator. As shown in fig. 10, the debugging method of the present embodiment includes the following steps:

step S1001: and at least a first coupling hole and a second coupling blind hole are formed on the surface of the dielectric block.

Specifically, after the dielectric block is formed, a preset region may be determined on the dielectric block according to the actual product requirement and empirical data, and at least a first coupling hole and a second coupling hole may be formed in the preset region by grooving, etching, or the like.

Step S1002: and placing the debugging element into the first coupling hole and the second coupling hole to obtain a first parameter and a second parameter.

The debugging member of this embodiment can be metal probe, metal screw rod, dielectric rod etc. and its specific form can be set up according to the concrete structure of blind hole.

After the debugging piece is arranged in the coupling hole, the magnetic field distribution in the dielectric block can be changed, so that the parameters of the dielectric resonator can be changed.

In a specific application, the debugging element may be placed in the first coupling hole, and the first parameter of the dielectric resonator is obtained by an oscilloscope or the like, and then the debugging element is placed in the second coupling hole, and the second parameter of the dielectric resonator is obtained by an oscilloscope or the like.

Step S1003: and setting a tuning piece in the first blind hole and/or the second blind hole according to the first parameter and the second parameter so as to enable the parameter of the dielectric resonator to be a preset parameter.

Be different from prior art, this embodiment debugs and acquire corresponding parameter through every coupling hole to dielectric filter's parameter respectively through setting up a plurality of coupling holes on the medium piece, can be fast and accurate acquire with predetermineeing the coupling hole that the parameter corresponds, consequently can be fast and accurate debugging dielectric resonator.

Specifically, a first difference between the first parameter and the preset parameter and a second difference between the second parameter and the preset parameter may be obtained, and whether the first difference is greater than the second difference is determined; if so, setting a tuning piece in the first coupling hole so as to enable the parameters of the dielectric resonator to be preset parameters; and if not, setting a tuning piece in the second coupling hole so as to enable the parameters of the dielectric resonator to be preset parameters.

If the first difference is larger than the second difference, the debugging sensitivity of the first coupling hole to the parameter is considered to be larger than the debugging sensitivity of the second coupling hole to the parameter, and the first coupling hole can be provided with a tuning piece so as to adjust the parameter of the dielectric resonator through the tuning piece; if the first difference is smaller than the second difference, the tuning sensitivity of the second coupling hole to the parameter is considered to be larger than the tuning sensitivity of the first coupling hole to the parameter, and the tuning element can be arranged in the second coupling hole to adjust the parameter of the dielectric resonator through the tuning element.

In the above embodiment, the plurality of coupling holes are sequentially debugged, and one coupling hole having the highest sensitivity for parameter debugging of the dielectric filter is obtained from the plurality of coupling holes as a final coupling hole.

In the tuning process of the dielectric filter, limited by parameters such as the volume of the dielectric filter, a coupling hole, even if the tuning range or sensitivity of the coupling hole with the highest tuning sensitivity to the parameter may not meet the tuning requirement, in order to solve the problem, the application further provides a tuning method of a dielectric resonator according to a second embodiment. As shown in fig. 11, the debugging method of the present embodiment includes the following steps:

step S1101: and at least a first coupling hole and a second coupling hole are formed in the surface of the dielectric block.

Step S1101 is the same as step S1001 described above, and is not described herein again.

Step S1102: and placing the first debugging piece into the first coupling hole, and obtaining a first parameter.

Step S1102 is the same as step S1002, and is not described herein.

Step S1103: and placing the second debugging part into the second coupling hole, and obtaining a second parameter.

It should be noted that step S1103 differs from step S1002 described above in that: after the first parameter is obtained, the first debugging member is remained in the first coupling hole, and then the second debugging member is placed in the second coupling hole.

Step S1104: and acquiring a first difference value between the first parameter and a first preset parameter, and judging whether the first difference value is larger than a first preset difference value.

Specifically, the first preset parameter may be a parameter of the dielectric filter when the first tuning piece is not inserted into the first coupling hole.

In the process of placing the first debugging piece into the first coupling hole, the parameters of the dielectric filter can change along with the change of the states of the depth and the like of the first debugging piece in the first coupling hole. The first parameter of this embodiment is the maximum value of the parameter of the dielectric filter in the debugging process, and the first difference is the difference between the maximum value and the first preset parameter.

Step S1105: and if the first difference is larger than the first preset difference, acquiring a second difference between the second parameter and a second preset parameter, and judging whether the second difference is larger than the second preset difference.

If the first difference is larger than the first preset difference, the first coupling hole can be considered to meet the requirement for coarse adjustment of the parameter, and the parameter of the dielectric filter can be further adjusted through the second coupling hole.

Further, if the first difference is smaller than or equal to the first preset difference, it may be determined that the first coupling hole cannot meet the requirement for coarse adjustment of the parameter, and therefore, the first debugging member may be used to continue debugging the next coupling hole.

Step S1106: and if the second difference is larger than the second preset difference, arranging a first tuning piece in the first coupling hole, and arranging a second tuning piece in the second blind hole.

If the second difference is greater than the second preset difference, the second coupling hole can be considered to meet the requirement for fine adjustment of the parameter, and a second tuning piece can be arranged in the second coupling hole. The tuning elements are arranged in the same manner as in the previous embodiment and will not be described in detail here.

Further, if the second difference is less than or equal to the second preset difference, it may be determined that the second coupling hole cannot meet the requirement for fine tuning of the parameter, and therefore, the next coupling hole may be continuously tuned by using the second tuning element.

Different from the prior art, the dielectric filter provided by the embodiment of the application adjusts the transmission zero point by arranging at least two coupling holes, and can weaken the sensitivity of each coupling hole to the transmission zero point, so that the debugging precision of the transmission zero point can be improved.

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.

Claims

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

the dielectric block forms at least two resonant cavities which are connected;

the first coupling hole is arranged on a first surface of the dielectric block, the second coupling hole is arranged on a second surface of the dielectric block, and the first surface and the second surface are arranged oppositely;

the metal layer covers the surface of the dielectric block, the surface of the first coupling hole and the surface of the second coupling hole; wherein the material of the dielectric filter at least comprises magnesium oxide, calcium oxide, titanium dioxide and zinc oxide.

2. The dielectric filter of claim 1, wherein the magnesium oxide accounts for 20-30% of the molar percentage; the calcium oxide accounts for 2 to 10 percent of the molar percentage; the titanium dioxide accounts for 50 to 75 percent of the molar percentage; the zinc oxide accounts for 0.1 to 5 percent of the molar percentage.

3. The dielectric filter of claim 1, wherein the at least two resonant cavities comprise a first resonant cavity and a second resonant cavity, the dielectric filter further comprising a first blind via and a second blind via, the first resonant cavity being provided with the first blind via, the second resonant cavity being provided with the second blind via.

4. The dielectric filter of claim 1, wherein a ratio of a depth of the first coupling hole to a depth of the second coupling hole is in a range of 0.8-1.2;

the ratio of the depth of the first coupling hole to the depth of the second coupling hole ranges from 1 to 1.2, so that negative coupling between the two resonant cavities is realized; the ratio of the depth of the first coupling hole to the depth of the second coupling hole ranges from 0.8 to 1, so that positive coupling between the two resonant cavities is realized.

5. The dielectric filter of claim 1, wherein a ratio of a depth of the first coupling hole to a radius of the first coupling hole is 0.9-1.1.

6. The dielectric filter of claim 1, wherein a thickness of the metal layer disposed in the first coupling hole is greater than a thickness of the metal layer disposed in the second coupling hole.

7. A dielectric filter as claimed in claim 1, characterized in that the chemical composition of the material of the dielectric filter is mgo-bCaO-cdio₂-dZnO, wherein the ratio of a, b, c and d is 0.2-0.3: 0.02-0.1: 0.5-0.7: 0.001-0.05.

8. A method of making a dielectric block, wherein the method is used to make a dielectric block according to any of claims 1-7, the method comprising:

providing raw materials corresponding to magnesium oxide, calcium oxide, titanium dioxide and zinc 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 block; and

removing the binder and sintering again to obtain the dielectric block.

9. A method for producing a dielectric filter, the method being used for producing the dielectric filter according to any one of claims 1 to 7, the method comprising:

providing a dielectric block prepared by the method of claim 8;

and covering a metal layer on the surface of the dielectric block to obtain the dielectric filter.

10. A communication device, characterized in that the communication device comprises an antenna and a dielectric filter according to any of claims 1-7, the antenna being coupled to the dielectric filter.