WO2020107431A1

WO2020107431A1 - Dielectric resonator and dielectric filter

Info

Publication number: WO2020107431A1
Application number: PCT/CN2018/118657
Authority: WO
Inventors: 周普科; 蒲国胜
Original assignee: 华为技术有限公司
Priority date: 2018-11-30
Filing date: 2018-11-30
Publication date: 2020-06-04

Abstract

An embodiment of the present application discloses a dielectric resonator and a dielectric filter using same. The dielectric resonator comprises a metal cavity and a dielectric cylinder, wherein the dielectric cylinder is located in the metal cavity, and the metal cavity comprises a bottom part and a top cover which are oppositely arranged. The dielectric resonator further comprises a tuning member and a metal part, wherein the tuning member penetrates the top cover and extends into the metal cavity, and then is coupled with the dielectric cylinder so as to adjust the frequency and coupling of the dielectric resonator, an upper end face of the dielectric cylinder is fixedly connected to and is in a short-circuit state with the top cover, a lower end face of the dielectric cylinder is fixedly connected to the metal part, and the metal part faces and is in an open-circuit state with the bottom part. The dielectric resonator provided in the embodiment of the present application has the advantages of being small in size and high in performance.

Description

Dielectric resonator and dielectric filter

Technical field

The present application relates to the field of microwave communication, in particular to a dielectric resonator and a dielectric filter using the same.

Background technique

With the development of microwave communication technology, communication circuits are increasingly demanding the miniaturization of electronic devices. Due to the loss of metal in traditional metal resonators, when the size of the metal resonator increases to a certain value, its Q value (inherent quality Factor) will not change much, its passband loss will also limit the performance of the filter unit, which greatly limits the development of wireless communication technology, and with the development of dielectric resonator technology, it is a miniaturized, high-performance filter The research and development of the system has given great inspiration. The research on dielectric resonator has become a hot spot in the field of microwave communication.

Summary of the invention

The present application provides a dielectric filter and a dielectric resonator. The dielectric resonator has the advantages of miniaturization and high performance.

In a first aspect, the present application provides a dielectric resonator. The dielectric resonator includes a metal cavity and a dielectric column. The dielectric column is located in the metal cavity. The metal cavity includes a bottom and a top cover that are oppositely arranged. At the same time, the dielectric resonator further includes a tuning element and a metal portion. The tuning element passes through The top cover extends into the metal cavity and is coupled with the dielectric column to adjust the frequency and coupling of the dielectric resonator. The upper end surface of the dielectric column is fixed to the top cover and is in a short-circuit state with the top cover, and the lower end surface of the dielectric column is fixed The metal part faces the bottom and is in an open state with the bottom.

In this application, by fixing the dielectric column to the top cover, and by providing a metal part that is open to the bottom between the dielectric column and the bottom of the metal cavity, the fixation of the dielectric column and the tuning of frequency and coupling are achieved. This structure requires low tolerance and is easy The dielectric column is installed, and the design of the dielectric resonator can be miniaturized, and the design of the open end of the dielectric column also provides an elastic space for the thermal expansion of the dielectric column and the metal cavity. This application is for the axial thermal expansion loss of the traditional dielectric resonator The problem is provided with a solution.

In one embodiment, the dielectric column includes a side surface connected between the upper end surface and the lower end surface, the dielectric column is provided with a tuning groove, the tuning groove is recessed from the side surface, and a gap is formed at the edge of the upper end surface The notch extends into the metal cavity, and part or all of the projected part of the tuner on the upper end face falls into the notch. This embodiment adopts the design of the tuning groove. The purpose of the tuning element being at least partially contained in the tuning groove is to enable the tuning element to enter the metal cavity close to the strong electric field area through the setting of the tuning slot, so that the tuning capability obtained by the tuning element Greatly enhanced. The application realizes the adjustment of the electromagnetic field in the dielectric resonator by the tuning part through the cooperation of the tuning slot and the tuning part, so as to achieve the purpose of tuning and coupling. The tuning groove is placed on the side of the dielectric column, this design can also greatly reduce the processing technology requirements. If the tuning hole design in the prior art is adopted, the alignment of the tuning piece and the tuning hole and the size of the tuning hole are processed. High processing requirements are put forward, because the tuning element needs to enter the tuning hole to achieve the effect of tuning control. With the tuning slot design in this embodiment, only the tuning element needs to be partially contained in the tuning slot. The size of the tuning element is also more relaxed. The size of the part of the tuning element contained in the tuning slot can achieve different coupling methods. Therefore, the coupling of the tuning element and the open tuning slot has an effect on the electromagnetic field of the dielectric resonator. The adjustment is also more flexible.

In one embodiment, the tuning groove extends from the upper end surface to the lower end surface of the dielectric column, and a lower end surface notch corresponding to the notch of the upper end surface is formed at the lower end surface. In this embodiment, the tuning slot is directly designed as a through slot, so that the dielectric column is easy to process.

In one embodiment, the bottom surface of the tuning groove away from the upper end surface is located between the upper end surface and the lower end surface, and the bottom surface of the groove extends from the side surface toward the center of the dielectric column and faces the notch. In the embodiment, the tuning groove is extended only to the middle position of the side surface. This design will not change the structure of the lower end surface of the dielectric column, which will provide more processing options for the metal part fixed on the lower end surface, such as using metal inkjet on the lower end surface. The metal part is formed in the same way. If the tuning groove adopts the technical solution of penetrating the dielectric column, it will result in the formation of a notch on the lower end surface, which is not suitable for the metal inkjet technical solution.

The groove bottom surface of the tuning groove in this embodiment may be designed as a concave structure. When the tuning element and the top cover extend into the metal cavity by screwing, since the tuning element and the top cover are both metal structures, it is possible Metal debris will fall into the metal cavity and affect the performance of the dielectric resonator. The concave structure on the bottom of the groove can collect metal shavings to prevent the metal shavings from falling on the bottom of the metal cavity. Furthermore, an adhesive layer may be designed on the bottom surface of the groove, and metal shavings may be pasted through the adhesive layer to fix the metal shavings on the bottom surface of the groove to reduce the impact on the dielectric resonator. Of course, the concave structure and the adhesive layer can exist at the same time, enhancing the effect of collecting and pasting metal scraps.

In one embodiment, the tuning member includes multiple tuning rods, and the multiple tuning rods include one or more coupled tuning rods and one or more frequency tuning rods. The number of tuning slots is the same as the number of tuning rods, and the tuning slots are spaced apart. Arranged on the side, multiple tuning rods are matched with different tuning slots one by one to control the coupling between the dual TM11 degenerate modes of the dielectric resonator and the frequency adjustment of the dual TM11 degenerate modes of the dielectric resonator. Through the design of the coupling tuning rod and the frequency tuning rod, not only the frequency adjustment of the dual TM11 degenerate modes is realized, but also the coupling adjustment between the degenerate modes can be realized. The multiple tuning design makes the tuning effect of the dielectric resonator more For comprehensive.

In one embodiment, the dielectric column has a centrally symmetric structure. The dielectric column includes a central axis that penetrates the center position of the upper end surface and the center position of the lower end surface, and the extending direction of the tuning groove is parallel to the extending direction of the central axis. Control the direction of the extension of the tuning groove to be consistent with the direction of the central axis of the dielectric column. Such a design will bring better matching effect to the tuning piece and the tuning groove. If the direction of the extension of the tuning groove is inconsistent with the direction of the central axis of the dielectric column, then The direction in which the tuning element extends into the resonator from the top cover will not follow the direction of the center line of the dielectric column, which also brings unnecessary trouble to the design of the tuning element and the design of the through hole on the top cover.

In one embodiment, the number of coupling tuning rods is one, the number of frequency tuning rods is two, and the number of tuning slots is three. The dielectric resonator in this embodiment can be applied to dual TM11 degenerate modes. The function of using two frequency tuning rods is to realize frequency control of two degenerate modes through two frequency tuning rods, while a coupling tuning rod is For coupling adjustment between two degenerate modes, this number of choices not only meets the needs of technical solutions but also reduces the cost of the product.

In one embodiment, the number of tuning slots is two or more, and on a plane perpendicular to the central axis, the shortest distance between the tuning slot and the central axis is equal. The line between the center of the cross section of the dielectric column and the first frequency tuning screw hole is perpendicular to the line between the center of the cross section of the dielectric column and the second frequency tuning screw hole, and the center of the cross section of the dielectric column and the coupling tuning screw hole Is perpendicular to or parallel to the connection of the first frequency tuning screw hole and the second frequency tuning screw hole. The position design of the tuning slot in this embodiment can obtain a pair of orthogonal TM11 degeneracy modes inside the dielectric resonator.

In one embodiment, the metal part is in the shape of a sheet, and is fixedly connected to the lower end surface. The design of the sheet-shaped metal part can greatly reduce the size of the dielectric resonator while obtaining the required frequency. The design of providing the metal part on the lower end surface can greatly reduce the height of the dielectric pillar when the dielectric resonator obtains the same Q value, thereby making the overall design of the dielectric resonator more compact.

In one embodiment, the outline of the metal portion is the same as the outline of the lower end surface, the size of the metal portion is less than or equal to the size of the lower end surface, and the centers of the cross sections of the two coincide. In this embodiment, the outline of the metal part is the same as the outline of the lower end surface, and the size of the two is the same, which can better reduce the radiation effect of the open end surface of the dielectric column, thereby improving the performance of the dielectric resonator.

In one embodiment, the size of the metal portion is smaller than the size of the lower end surface, a groove matching the size of the metal portion is provided on the lower end surface, and the metal portion is installed in the groove. Installing the metal part in the groove provided on the lower end surface can improve the stability of the connection between the metal part and the lower end surface of the dielectric column, which is equivalent to embedding the metal part at the lower end surface of the dielectric column, so that the metal part and the dielectric column are integrated into one , The metal part is not easy to fall off from the lower end surface.

In one embodiment, a gap is provided between the metal part and the inner wall of the groove, and the gap is used to absorb expansion of the metal part when heated. In a specific embodiment, since the thermal expansion coefficient of the metal part material is greater than the thermal expansion coefficient of the dielectric column material, because during the working process, the metal part will expand due to heat, the reserved gap can absorb the deformation of the metal part due to expansion and avoid The stress generated by the pressing between the metal part and the inner wall of the groove.

In one embodiment, the metal part is a metal film structure that completely or partially covers the lower end surface. The structure of the metal part using the metal film can greatly reduce the quality and size of the components, which is conducive to the lightweight and miniaturized design of the dielectric resonator.

In one embodiment, the size of the metal part in the direction perpendicular to the lower end surface is the thickness of the metal part, and the thickness of the metal part is greater than 0.03 mm and less than 1.5 mm. In the embodiment, the role of defining the thickness of the metal part between 0.03 mm and 1.5 mm is to obtain the ideal Q value of the dielectric resonator. If the metal part is designed too thick or too thin, the Q value of the dielectric resonator drops. In the working state, there is a physical current on the metal part, and it is necessary to keep the thickness of the metal part> 30 μm (ie 0.03 mm) to solve the deterioration of the Q value (deterioration of electrical performance) caused by the adhesion effect; and the thickness of the metal part is too large, which will make The current loss in the thickness direction of the metal part increases, thereby affecting the overall Q value (electrical performance), so the thickness of the metal part needs to be less than 1.5 mm.

In one embodiment, the thickness of the metal part is evenly distributed, which can reduce the influence of the metal part on the electromagnetic field in the cavity.

In one embodiment, the gap formed between the metal part and the bottom is greater than 1 mm. In the embodiment, the metal cavity is also made of metal, and when the gap between the metal part and the bottom of the metal cavity is too small, a pair The mutually parallel metal plate structure, that is, the cooperation between the metal part and the bottom of the metal cavity will produce a certain capacitance effect. The gap between the metal part and the bottom of the metal cavity is greater than 1 mm to prevent the capacitance effect from being too strong. Affect the distribution of electromagnetic field inside the dielectric resonator. Too strong a capacitance effect will make the TM11 mode the lowest-frequency fundamental resonance mode, and the resonance frequency of the TM11 degenerate dual mode (the operating mode desired to be used) will increase, thereby reducing the purpose of miniaturization of the dielectric resonator.

In a second aspect, the present application discloses a dielectric filter including an input port, an output port, and the dielectric resonator according to any one of the above embodiments, the dielectric resonator is connected in series between the input port and the output port between.

In one embodiment, the dielectric filter further includes a metal resonator, and the metal resonator is arranged in series with the dielectric resonator.

BRIEF DESCRIPTION

FIG. 1a is a schematic structural diagram of a dielectric filter in an embodiment of the present invention;

1b is a schematic structural diagram of a dielectric filter in another embodiment of the present invention;

2 is a top view of a dielectric resonator of the present invention (without the top cover);

3 is a cross-sectional view along the line A-A of FIG. 1 in the present invention (with a top cover added);

4 is a top view of a top cover of a dielectric resonator of the present invention;

5 is a cross-sectional view taken along line B-B of FIG. 3 in the present invention;

6a is a top view of a dielectric column according to an embodiment of the present invention;

6b is a bottom view of a dielectric column according to an embodiment of the present invention;

6c is a front view of a dielectric column according to an embodiment of the present invention;

7a is a top view of a dielectric column according to another embodiment of the invention;

7b is a bottom view of a dielectric column according to another embodiment of the invention;

7c is a front view of a dielectric column according to another embodiment of the invention;

8a is a top view of a dielectric column according to a third embodiment of the invention;

8b is a bottom view of a dielectric column of a third embodiment of the invention;

8c is a front view of a dielectric column of a third embodiment of the invention;

9 is a diagram of the positional relationship between the dielectric column and the tuner in one embodiment of the present invention;

10 is a diagram of the positional relationship between the dielectric column and the tuner in another embodiment of the invention;

11a is a top view of the distribution of the top cover tuning members according to an embodiment of the present invention;

11b is a front view of a top cover tuning member according to an embodiment of the present invention;

11c is a distribution diagram of a dielectric column tuning groove in an embodiment of the present invention;

FIG. 12a is a top view of the distribution of the top cover tuning members according to another embodiment of the present invention;

12b is a front view of another embodiment of the top cover tuning member of the present invention;

12c is a distribution diagram of a dielectric column tuning groove in another embodiment of the present invention;

13a is a distribution diagram of the electromagnetic field of the H mode of the dielectric resonator in an embodiment of the present invention;

13b is a distribution diagram of the electromagnetic field of the V mode of the dielectric resonator in an embodiment of the present invention;

14a and 14b are distribution diagrams of H-mode and V-mode electromagnetic fields of dielectric resonators in another embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise stated, "at least one" refers to one or more than one; "at least one" refers to one or more than one; "multiple" refers to two or two the above.

The present application provides a dielectric filter that can be applied to a filter unit of a base station of a microwave communication system and a dielectric resonator in the dielectric filter. In the microwave communication circuit, after the analog/digital information is processed by the modulator, a high-frequency digital signal is obtained, and the filter separates and combines the received high-frequency signal to obtain the signal of the required frequency, and then the signal is passed through the RF amplifier The power is adjusted and finally fed to the antenna for transmission. As shown in FIGS. 1a and 1b, in a specific embodiment, an input port 250 and an output port 260 are externally connected to the dielectric filter 200, and at least one dielectric resonator 100 is connected in series between the output port 250 and the output port 260.

In one embodiment, the dielectric filter 200 further includes a metal resonator 220. The metal resonator 220 is arranged in series with the dielectric resonator 100. In one embodiment, as shown in FIG. 1a, the number of dielectric resonators 100 is multiple, and the number of metal resonators 220 is also multiple. The plurality of dielectric resonators 100 and the plurality of metal resonators 220 are alternately arranged in series one by one. In one embodiment, as shown in FIG. 1b, the number of dielectric resonators 100 is multiple, and the number of metal resonators 220 is also multiple. The dielectric filter 200 includes a plurality of resonator units arranged in series, and each resonator unit includes two metal resonators 220 and a dielectric resonator 100 connected in series between the two metal resonators 220. In other embodiments, the series arrangement of the plurality of dielectric resonators 100 and the plurality of metal resonators 220 may also be in other ways, such as two-two alternating arrangement, two-one alternating arrangement, and so on. In other embodiments, the number of dielectric resonators 200 may be one. In other embodiments, the number of metal resonators 220 may be one.

The dielectric filter 200 has a plurality of communicating chambers 210 inside. According to the performance requirements of the dielectric filter 200, the layout of the chambers 210 may be designed, and each chamber 210 may be selectively provided with a dielectric resonator 100 or a metal resonator 220. A plurality of chambers 210 are provided with coupled coupling windows 230. Each coupling window 230 is provided with a coupling part 240 for connecting the dielectric resonator 100 and the metal resonator 220. The coupling part 240 is controlled to complete resonance Electromagnetic coupling between devices to provide filters with a certain bandwidth.

In a specific embodiment, the coupling part 240 is formed of a metal wire, one end of the metal wire is connected to the bottom of the chamber 210 where the dielectric resonator 100 is located, and the other end is connected to the bottom or top of the chamber 210 where the metal resonator 220 is located or a metal resonator On the metal resonance component of 220, by adjusting the position and connection height of the metal wire, the coupling between the dielectric resonator 100 and the metal resonator 220 can be controlled.

In other embodiments, the dielectric filter 200 may only include a plurality of dielectric resonators 100 connected in series between the input port 250 and the output port 260, but not include the metal resonator 220.

The dielectric resonator 100 shown in FIGS. 2 and 3 includes a metal cavity 10, a dielectric column 20, a tuning member 30 and a metal part 40, wherein the metal cavity 10 includes a bottom 11, a top cover 12 and a cavity wall 13, the dielectric The post 20 is located inside the metal cavity 10. The bottom 11 and the top cover 12 are oppositely arranged. That is, the bottom 11 is parallel or substantially parallel to the top cover 12, and a gap is formed between the bottom 11 and the top cover 12. The inner surface of the bottom 11 and the inner surface of the top cover 12 are both flat, and the direction extending between the inner surface of the top cover 12 and the inner surface of the bottom 11 is the first direction. In the first direction, the dimension of the dielectric column 20 extends is the height h of the dielectric column 20, and in the first direction, the dimension of the metal cavity 10 is the internal height H of the metal cavity 10. The height h of the dielectric column 20 is smaller than the internal height H of the metal cavity 10. In the embodiment, the upper end surface 21 of the dielectric column 20 is fixed to the top cover 12 to form a short-circuit electrical connection, the lower end surface 23 of the dielectric column 20 is kept at a certain distance from the bottom of the metal cavity 10, and the metal has a thickness of d in the first direction The portion 40 is provided on the lower end surface 23 of the dielectric column 20. There is a certain gap between the metal portion 40 and the bottom 11, so that the dielectric column 20 and the bottom 11 are kept in an open state.

In a specific embodiment, the method for fixing the upper end surface 21 to the top cover 12 is: first spraying a layer of silver powder on the lower surface of the top cover 12, and then soldering the dielectric column 20 to the surface of the top cover 12 with solder paste On the silver powder, this operation not only ensures the fixing of the upper end surface 21 of the dielectric column 20 and the top cover 12, but also achieves the effect of short-circuit electrical connection between the two.

The upper and lower ends of the dielectric column of the traditional TM mode dielectric resonator are short-circuited to the bottom and top of the metal cavity through metallization. However, due to the strong electric field at the bottom and top of the metal cavity, it will cause metal surface loss and affect the resonator performance. The dielectric resonator 100 in this embodiment uses a short-circuit electrical connection between the upper end surface 21 and the top cover 12, and at the lower end, the height h of the dielectric column 20 is less than the internal height H of the metal cavity 10, thereby ensuring the metal There is a certain gap between the portion 40 and the bottom 11 so that the lower end surface 23 and the bottom 11 form an open circuit. This upper short circuit and lower open circuit structure design can ensure that the single cavity unloaded Q value of the dielectric resonator 100 is better than the traditional two ends. The design of short circuit, and setting the open end on the lower end surface 23 of the dielectric column 20 instead of the upper end surface 21 is to facilitate the tuning member 30 to enter the metal cavity 10 from the top cover 12 to realize the tuning control of the dielectric column 20 in a specific embodiment.

At the same time, due to the large difference in material between the dielectric column 20 and the metal cavity 10, the thermal expansion coefficients of the two are different. If the two ends are short-circuited, the deformation of the two will not be uniform when the operating temperature changes. Stress is generated at the place, which affects the stability of the structure. In this embodiment, the lower end surface 23 of the dielectric column 20 and the bottom 11 form a gap to avoid the stress at the connection caused by different thermal expansion coefficients. In this application, by fixing the dielectric column 20 to the top cover 12, and by providing a metal part 40 open to the bottom between the dielectric column 20 and the bottom of the metal cavity 10, the fixing of the dielectric column 20 and the tuning of frequency and coupling are achieved. This structure Low tolerance requirements, easy to install the dielectric pillar 20, and can make the dielectric resonator miniaturized design, and the design of the open end of the dielectric pillar 20 also provides an elastic space for the thermal expansion of the dielectric pillar 20 and the metal cavity 10, which is traditional The solution to the problem of axial thermal expansion mismatch of dielectric resonators.

In a specific embodiment, the dielectric resonator 100 supports dual TM11 degenerate modes. The dual mode resonator in the embodiment can couple energy from one degenerate mode to another degenerate mode, each TM11 degenerate mode is equal To form an electric resonator, the function of the tuning element 30 is to control the formed electric resonator: the tuning element 30 passes through the top cover 12 into the metal cavity 10, and then is inserted into the tuning groove 24 distributed on the side 22 of the dielectric column 20, through The depth at which the tuner 30 is inserted into the tuning slot 24 is controlled to realize the control of the resonator.

The tuning member 30 extends into the metal cavity 10 through the top cover 12 and is coupled with the dielectric column 20 to adjust the frequency and coupling of the dielectric resonator. In a specific embodiment, as shown in FIGS. 4 and 5, the horizontal cross-section of the top cover 12 is square, and a through hole 14 is opened in the top cover 12, and the position of the through hole 14 is based on the tuning groove on the dielectric column 24, the inner diameter of the through hole 14 should ensure that the tuner 30 can enter the metal cavity 10 without influence, and at the same time there is a limit at the through hole 14 that can control the size of the tuner 30 extending into the metal cavity 10 The positioning member 15 controls the size of the tuning member 30 extending into the metal cavity 10 through the setting of the limiting member 15.

In a specific embodiment, as shown in FIG. 5, the tuning member 30 is a screw with a thread, and a through hole 14 with an inner diameter larger than the screw diameter is opened on the top cover 12, and the through hole 14 is on the upper surface of the top cover 12 The opening is provided with a nut that cooperates with the screw (tuning member 30). The nut is the limiting member 15. When the size of the tuning member 30 (screw) extending into the metal cavity 10 needs to be adjusted, only the The tuning element 30 (screw) can be rotated outside the metal cavity 10.

In a specific embodiment, the top cover 12 may also be provided with a threaded through hole 14 that cooperates with the screw (tuning member 30). At this time, the threaded through hole 14 plays a role in the screw The limiting function is the limiting member 15. The tuning member 30 (screw) passes through the threaded through hole 14 (limiting member 15) into the metal cavity 10. By rotating the tuning member 30 outside the metal cavity 10 To control the size of the metal cavity 10.

As shown in FIGS. 6a to 8c, in a specific embodiment, the dielectric column 20 is a cylinder, the upper end surface 21 is parallel to the lower end surface 23, the central axis of the dielectric column 20 is parallel to the first direction, and is on the side of the dielectric column 20 Tuning grooves 24 are distributed on 22, and the tuning grooves 24 extend from the edge of the upper end surface 21 to the lower end surface 23, and have a groove structure on the side surface 22 in an open state, and the direction in which the tuning groove 24 extends downward is parallel to the first In the direction, the tuning groove 24 may select a trapezoidal groove, a V-shaped groove, or an arc-shaped groove. Correspondingly, the tuning groove 24 forms a trapezoidal, V-shaped, or arc-shaped notch 25 at the edge of the upper end surface 21.

The tuning element 30 extends into the metal cavity 10, and at least part of the tuning element 30 is accommodated in the tuning groove 24. Specifically, after the tuner 30 enters the metal cavity 10 from the through hole 14, it is inserted into the tuning groove 24 from the notch 25. As shown in FIGS. 6a to 8c, the embodiment uses the design of the arc-shaped tuning groove 24 instead of the tuning hole.

Wherein, the projection of the tuner 30 on the upper end surface 21 falls completely or partially into the gap 25 to ensure the adjustment of the dielectric column 20 by the tuner 30. In the embodiment shown in FIG. 9, the projection part of the tuner 30 falls into the notch 25 at the projected portion of the upper end surface 21. In the embodiment shown in FIG. 10, the projection of the tuner 30 on the upper end surface 21 all falls into the notch 25.

The purpose of the tuner 30 being at least partially accommodated in the tuning slot 24 is to enable the tuner 30 to enter the metal cavity 10 close to the strong electric field region through the setting of the tuning slot 24, thereby greatly enhancing the tuning ability obtained by the tuner 30 . In the present application, through the cooperation of the tuning slot 24 and the tuning element 30, the tuning element 30 can adjust the electromagnetic field in the dielectric resonator to achieve the purpose of tuning and coupling. The tuning groove 24 is arranged on the side of the dielectric column, such a design can also greatly reduce the processing technology requirements. If the tuning hole design in the prior art is adopted, the alignment of the tuning piece and the tuning hole and the size of the tuning hole are processed All have high processing requirements, because the tuning element needs to enter the tuning hole to achieve the effect of tuning control. With the tuning slot design in this embodiment, only the tuner 30 needs to be partially accommodated in the tuning slot 24. However, the size requirements of the tuner 30 are also more relaxed. The size of the portion of the tuner 30 contained in the tuning slot 24 can realize different coupling methods. Therefore, the tuner 30 and the open tuning slot 24 Coupling, the adjustment of the electromagnetic field of the dielectric resonator is also more flexible.

In the embodiment shown in FIGS. 6a to 6c, the tuning groove 24 extends to the lower end surface 23 of the dielectric column 20, and a notch 29 corresponding to the upper end surface is formed on the lower end surface 23. At this time, the metal portion 40 provided on the lower end surface 23 The size can be adjusted to reduce (as shown in Figure 6b and Figure 6c), the reduction adjustment at this time is to achieve the same size as the lower end surface 23 under the premise of the same size reduction, and the reduction of the metal part 40 The size is the maximum size that can be achieved without affecting the notch 29 of the lower end face 23.

In the embodiment shown in FIG. 7a to FIG. 7c, the length of the tuning groove 24 is L which is smaller than the height h of the dielectric column 20. The tuning groove 24 only forms a notch 25 on the upper end surface, which is At the cross section of the dielectric column whose end distance is L, the tuning groove 24 forms a groove bottom surface 28, and the gap 25 formed by the groove bottom surface 28 and the tuning groove 24 at the upper end surface 23 is the same size and parallel to each other. At this time, the lower end surface of the dielectric column The size and shape of 23 are not affected by the tuning groove 24.

The groove bottom surface 28 of the tuning groove 24 in this embodiment may be designed as a concave structure. When the tuning element 30 and the top cover 12 extend into the metal cavity 10 by screwing, the tuning element 30 and the top cover All 12 are metal structures, and metal chips may fall into the metal cavity 10, which may affect the performance of the dielectric resonator 100. The concave structure of the bottom surface 28 of the groove can collect metal shavings to prevent the metal shavings from falling on the bottom of the metal cavity 10. An adhesive layer may be designed on the bottom surface 28 of the groove, and metal shavings may be pasted through the adhesive layer to fix the metal shavings on the bottom surface 28 of the groove, thereby reducing the impact on the dielectric resonator 100. Of course, the concave structure and the adhesive layer can exist at the same time, enhancing the effect of collecting and pasting metal scraps.

In a specific embodiment, the lower end surface 23 of the dielectric column 20 is further provided with a metal part 40. On the one hand, by setting the metal part 40, the resonance frequency can be limited (so that the TM11 mode frequency is below the TM11 mode); On the one hand, the dielectric resonator added to the metal part can ensure that the height H of the metal cavity 10 can be miniaturized at the same operating frequency, which is beneficial to the requirements of the miniaturized design of the dielectric resonator. There is a strong electric field around the metal part 40, and a certain gap needs to be maintained to prevent power breakdown. The function of the metal part 40 is to depress the TM11 degenerate dual mode, so that the resonance frequency of the dielectric resonator accommodates the height H of the metal cavity 10 of the dielectric column 20 ("desensitization" means insensitivity, that is, the metal cavity The height H of the metal can be shortened. In this case, the resonance frequency of the TM11 double degenerate mode changes little or even unchanged. Therefore, the present application can achieve the purpose of shortening the height H of the metal cavity 10, which is beneficial to small products.化设计。 Design.

The metal portion 40 is in the shape of a sheet, and is fixedly connected to the lower end surface 23. The design of the sheet-shaped metal portion 40 can greatly reduce the size of the dielectric resonator while obtaining the required frequency. The design of providing the metal part 40 on the lower end surface 23 can greatly reduce the height of the dielectric pillar when the dielectric resonator obtains the same Q value, thereby making the overall design of the dielectric resonator more compact.

In a specific embodiment, the metal part 40 has a shape profile similar to the lower end surface 23 of the dielectric column 20, but is slightly smaller in size (see FIGS. 6a to 6c) or the same (see FIGS. 7a to 7c). In one embodiment, the outline of the metal portion 40 is the same as the outline of the lower end surface 23, the size of the metal portion 40 is less than or equal to the size of the lower end surface 23, and the centers of the cross sections of the two coincide. In this embodiment, the outline of the metal portion 40 is the same as the outline of the lower end surface 23, and the size of the two is the same, which can better reduce the radiation effect of the open end surface of the dielectric column, thereby improving the performance of the dielectric resonator.

In the embodiment shown in FIGS. 6 a to 6 c, the dielectric column 20 is a cylinder, and the upper and lower end surfaces are two parallel circular surfaces. The side surface 22 is provided with an arc-shaped tuning groove 24, and the tuning groove 24 is separated from the dielectric column 20 The upper end face 21 extends to the lower end face 23, and an arc-shaped notch 29 is formed at the edge of the lower end face 23, in order to avoid the influence of the setting of the metal part 40 on the notch 29 opened by the tuning groove 24 at the lower end face 23, as shown in FIG. 6b and As shown in FIG. 6c, the metal portion 40 is a round metal foil, and the center of the metal foil coincides with the center of the lower end surface 23, but the size is smaller than the lower end surface 23, and the upper limit of the size must meet: the metal portion 40 is perpendicular to The projection in the direction of the lower end surface 23 does not coincide with the notch 29 on the lower end surface 23.

In the embodiment shown in FIGS. 7a to 7c, the dielectric column 20 is a cylinder, the upper and lower end surfaces of the dielectric column 20 are two parallel circular planes, and the side surface 22 of the dielectric column 20 is provided with an arc-shaped tuning groove 24 The tuning groove 24 extends from the upper end surface 21 of the dielectric column 20 to the middle of the dielectric column 20 to form a groove bottom surface 28. At this time, the tuning groove 24 does not form a gap in the lower end surface 23, as shown in FIGS. 7b and 7c, the metal part at this time The shape and size of 40 are the same as the lower end surface 23. In a specific embodiment, the metal part 40 can be fixed to the lower end surface 23 by means of electroplating, welding or bonding, or can be attached to the lower end surface 23 by metal spraying A metal thin film is formed on the metal thin film, which is the metal part 40 in the figure. The metal part 40 adopts a metal film structure, which can greatly reduce the quality and size of the components, which is conducive to the weight reduction of the dielectric resonator. Miniaturized design. Forming the metal part 40 by metal spraying saves the process flow of plating, welding or adhering the metal part 40 to the lower end surface 23, and simplifies the processing steps.

In the embodiment shown in FIGS. 8 a to 8 c, the dielectric column 20 is a cylinder, and the upper and lower end faces are two parallel circular planes. The side 22 is provided with an arc-shaped tuning slot 24. The tuning slot 24 is separated from the dielectric column 20 The upper end surface 21 extends to the middle of the dielectric column 20 to form a groove bottom surface 28. At this time, the tuning groove 24 does not form a gap in the lower end surface 23, as shown in FIG. 8b and FIG. 8c, the lower end surface 23 of the dielectric column 20 is opened for The groove 26 of the metal part 40 is fixed, and the outline of the groove 26 is similar to the metal part 40, for example: all are round, and the center of the circle coincides with the center of the lower end surface, but the size of the round surface of the groove 26 is larger than that of the metal part 40 The outline edge of the metal part 40 and the inner wall of the groove 26 form a gap 27, and the gap 27 is used to absorb expansion of the metal part 40 when heated. In a specific embodiment, since the thermal expansion coefficient of the material of the metal part 40 is greater than the thermal expansion coefficient of the material of the dielectric column 20, because during the working process, the metal part 40 will expand due to heat, the reserved gap 27 can absorb the metal part 40 because of The deformation caused by the expansion avoids the stress caused by the pressing between the metal portion 40 and the inner wall of the groove 26.

In a specific embodiment, the dimension of the metal portion 40 in the direction perpendicular to the lower end surface 21 is the thickness of the metal portion 40, and the thickness of the metal portion 40 is greater than 0.03 mm and less than 1.5 mm. In the embodiment, the role of defining the thickness of the metal part 40 to be between 0.03 mm and 1.5 mm is to obtain the ideal Q value of the dielectric resonator. If the metal part 40 is designed too thick or too thin, the Q value of the dielectric resonator decreases . In the working state, there is a solid current on the metal part 40, and it is necessary to keep the thickness of the metal part 40> 30 μm (ie 0.03 mm) to solve the deterioration of the Q value caused by the adhesion effect (deterioration of electrical performance); If it is large, the current loss in the thickness direction of the metal part 40 will increase, which will affect the overall Q value (electrical performance) of the dielectric resonator, so the thickness of the metal part 40 needs to be less than 1.5 mm. Specifically, the thickness of the metal portion 40 is evenly distributed, so that the influence of the metal portion 40 on the electromagnetic field in the cavity can be reduced.

The distance between the metal part 40 and the bottom 11 of the metal cavity 10 is greater than 1 mm. Since the metal cavity 10 is also made of metal, and the gap between the metal part 40 and the bottom of the metal cavity 10 is too small, a pair of parallel metal plate structures will be formed, that is, the metal part 40 and the bottom of the metal cavity 10 cooperate to produce For a certain capacitance effect, the gap between the metal part 40 and the bottom of the metal cavity 10 is set to be greater than 1 mm in order to prevent the capacitance effect from being too strong and affecting the distribution of the electromagnetic field inside the dielectric resonator. Too strong a capacitance effect will make the TM11 mode the lowest-frequency fundamental resonance mode, and the resonance frequency of the TM11 degenerate dual mode (the operating mode desired to be used) will increase, thereby reducing the purpose of miniaturization of the dielectric resonator.

In a specific embodiment, the tuning member 30 includes a plurality of tuning rods (31/32). The plurality of tuning rods (31/32) include one or more coupling tuning rods 31 and one or more frequency tuning rods 32. The coupling tuning rod 31 is used to realize the coupling between the double degenerate modes, the number of which is selected according to the specific situation. The frequency tuning rod 32 is used to adjust the resonance frequency of the double degenerate mode, and the number thereof is selected according to the specific situation. Corresponding to the number of tuning rods (31/32), a corresponding number of tuning slots 24 are also opened in the dielectric column 20. That is, the number of tuning slots 24 is the same as the number of tuning levers (31/32). A plurality of tuning grooves 24 are arranged on the side surface 22 at intervals. A plurality of tuning rods (31/32) cooperate with different tuning slots 24 in one-to-one correspondence. The single adjustment slot 24 cooperates with a coupling tuning rod 31 or with a frequency tuning rod 32. In the specific embodiment shown in FIGS. 11a to 12c, the tuning element 30 is a coupling tuning rod B1, frequency tuning rods B2 and B3, and three tuning slots G1, G2 and G3 are correspondingly opened on the side 22 of the dielectric column 20, That is, the tuning slot G1 cooperates with the coupling tuning rod B1, the tuning slot G2 cooperates with the frequency tuning rod B2, the tuning slot G3 cooperates with the frequency tuning rod B3, and the connections between the tuning slots G1, G2, and G3 to the center O of the dielectric column 20 are OG1, respectively , OG2 and OG3.

In a specific embodiment, the distribution of the tuning grooves G1, G2, and G3 is shown in FIG. 11c. The dielectric column 20 is cylindrical, the horizontal cross section of the metal cavity 10 is square, and O is the center of the upper end surface 21, which is connected to OG1. , OG2 and OG3, as shown in FIG. 11c, OG2 and OG3 respectively coincide with the diagonal of the metal cavity 10, and OG1 is perpendicular to G2G3.

The principle of the design distribution of the above tuning slots is explained below: according to the tuning slots G1, G2 and G3 distributed in FIG. 11c, the dual TM11 degenerate mode electromagnetic fields as shown in FIGS. 13a and 13b will be obtained, points and forks respectively The electric field entering or leaving the screen, arrows E1 and E2 respectively represent the direction of the electric field line; the dotted line of the circle represents the magnetic field, and the arrow on the dotted line represents the direction of the magnetic field. One of these modes is called H mode (see Figure 13a), and the other is called V mode (see Figure 13b).

In another specific embodiment, the distribution of the tuning grooves G1, G2, and G3 is shown in FIG. 12c, the dielectric column 20 is cylindrical, the horizontal cross section of the metal cavity 10 is square, and O is the center of the upper end surface 21, connected OG1, OG2 and OG3, as shown in FIG. 12c, OG2 and OG3 respectively coincide with the diagonal of the metal cavity 10, and OG1 is perpendicular to G2G3.

The principle of the design distribution of the above tuning slots is explained below: according to the tuning slots G1, G2 and G3 distributed in FIG. 12c, the dual TM11 degenerate mode electromagnetic fields as shown in FIGS. 14a and 14b will be obtained, points and forks respectively The electric field entering or leaving the screen, arrows E3 and E4 respectively represent the direction of the electric field line; the dotted line of the circle represents the magnetic field, the arrow on the dotted line represents the direction of the magnetic field, one mode is called H mode (as shown in Figure 14a), the other This kind is called V mode (shown in Fig. 14b).

In the above two specific embodiments, the resonance frequencies of the H mode and the V mode are adjusted by the depths at which the frequency tuning rods B2 and B3 are inserted into the tuning slots G2 and G3, and the coupling between the H mode and the V mode is coupled by the tuning rod B1 is inserted into the tuning groove G1 to adjust the depth, so that the tuning control of the self-coupling and mutual coupling of the H mode and the V mode outside the metal cavity 10 is realized.

The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present It should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

A dielectric resonator includes a metal cavity and a dielectric column. The dielectric column is located in the metal cavity. The metal cavity includes a bottom portion and a top cover that are oppositely arranged. The dielectric resonator further includes: A tuning element and a metal part, the tuning element extends into the metal cavity through the top cover and is coupled with the dielectric column to adjust the frequency and coupling of the dielectric resonator, the upper end surface of the dielectric column Fixed to the top cover and short-circuited with the top cover, the lower end surface of the dielectric column is fixed to the metal portion, the metal portion faces the bottom and is between the bottom Open circuit state.
The dielectric resonator according to claim 1, wherein the dielectric column includes a side surface connected between the upper end surface and the lower end surface, the dielectric column is provided with a tuning groove, and the tuning groove The side surface is concave and a notch is formed at an edge of the upper end surface, the tuning element extends into the metal cavity from the notch, and the projection of the tuning element on the upper end surface falls in whole or in part Into the gap.
The dielectric resonator of claim 2, wherein the tuning groove extends from the upper end surface to the lower end surface.
The dielectric resonator according to claim 2, wherein the bottom surface of the groove away from the upper end surface of the tuning groove is located between the upper end surface and the lower end surface, and the bottom surface of the groove extends from the side surface toward The center of the dielectric column extends and faces the notch.
The dielectric resonator according to any one of claims 2-4, wherein the tuning member comprises a plurality of tuning rods, and the plurality of tuning rods include one or more coupled tuning rods and one or more frequencies Tuning rods, the number of the tuning slots is the same as the number of the tuning rods, the tuning slots are arranged at intervals on the side, and the plurality of tuning rods are matched with different tuning slots one by one correspondingly, Control the coupling between the dual TM11 degenerate modes of the dielectric resonator and the frequency adjustment of the dual TM11 degenerate modes of the dielectric resonator.
The dielectric resonator according to claim 5, wherein the number of the coupling tuning rods is one, the number of the frequency tuning rods is two, the number of the tuning slots is three, and the three The tuning grooves are distributed on the sides.
The dielectric resonator according to any one of claims 2-4, wherein the dielectric column has a centrally symmetric structure, and the dielectric column includes a central position penetrating the upper end surface and a central position of the lower end surface The central axis, the extending direction of the tuning groove is parallel to the extending direction of the central axis.
The dielectric resonator according to claim 7, wherein the number of the tuning grooves is two or more, and on a plane perpendicular to the central axis, each of the tuning grooves and the central axis The shortest distance between them is equal.
The dielectric resonator according to any one of claims 1 to 8, wherein the metal part is in a sheet shape and fixedly connected to the lower end surface.
The dielectric resonator according to claim 9, wherein the outline of the metal portion is the same as the outline of the lower end surface, the size of the metal portion is less than or equal to the size of the lower end surface, and the two are transverse The centers of the sections coincide.
The dielectric resonator according to claim 9, wherein the size of the metal portion is smaller than the size of the lower end surface, a groove matching the size of the metal portion is provided on the lower end surface, and the metal portion Installed in the groove.
The dielectric resonator according to claim 11, wherein a gap is provided between the metal portion and the inner wall of the groove, and the gap is used to absorb expansion of the metal portion when heated.
The dielectric resonator according to any one of claims 1 to 8, wherein the metal portion has a metal film structure that covers the lower end surface in whole or in part.
The dielectric resonator according to any one of claims 9 to 13, wherein the dimension of the metal portion in the direction perpendicular to the lower end surface is the thickness of the metal portion, and the The thickness is greater than 0.03 mm and less than 1.5 mm.
The dielectric resonator according to claim 14, wherein the thickness of the metal portion is uniformly distributed.
The dielectric resonator according to any one of claims 1 to 15, wherein the gap formed between the metal portion and the bottom is greater than 1 mm.
A dielectric filter, characterized in that it includes an input port, an output port and the dielectric resonator of at least one of claims 1-16, the dielectric resonator is connected in series to the input port and the output port between.
The dielectric filter according to claim 17, wherein the dielectric filter further comprises a metal resonator, and the metal resonator is arranged in series with the dielectric resonator.