A cavity mixed dielectric resonant structure for filter and filter

Abstract

The present invention discloses a cavity hybrid dielectric resonant structure for a filter and a filter, which comprises a filter and a dielectric resonant rod arranged in the cavity of the filter, wherein the dielectric resonant rod comprises a coaxially arranged middle resonant unit and an end resonant unit, at least one end resonant unit is arranged at each of the two ends of the middle resonant unit, and the dielectric constant of the middle resonant unit is greater than the dielectric constant of the end resonant unit. The present invention is not only simple in structure, but also can meet the requirements of the cavity dielectric filter for higher Q value and smaller volume.

Description

Technical Field

[0001] The invention relates to a resonant structure and a filter, belonging to the technical field of passive antenna feed devices in the field of wireless network communications, and in particular to a cavity mixed dielectric resonant structure and a filter for a filter. Background Art

[0002] With the rapid development of the fourth generation of mobile communications to the fifth generation of mobile communications, the requirements for high performance and miniaturization of communication equipment are increasing, and the use of dielectric filters has gradually become more frequent. Traditional TM mode dielectric filters mostly use a single dielectric constant resonance method. Although this method can compress the volume and increase the Q value accordingly, the improvement in Q value is not obvious. In fact, it is only about 10% higher than the cavity filter of the same volume, and the advantage of volume reduction is not significant. At the same time, a TM mode dielectric filter is disclosed in Chinese invention patent CN103151581B. In paragraphs [0041-0049] and the appendix of its specification, Figure 4 and attached Figure 5 A dielectric resonator structure is disclosed, and the two ends of the dielectric resonator are respectively connected to a connecting seat and a supporting seat. The connection process uses a low-loss process. The above-mentioned connection method ensures that the dielectric resonator and the upper and lower structures are tightly and reliably connected, and ensures the low-loss transmission of the radio frequency microwave signal between the resonator and the upper and lower seats, while also ensuring the high Q value (quality factor) of a single resonant cavity unit in the entire dielectric filter. Although the structure can also be regarded as a three-stage structure, it should be pointed out that the purpose of the three-stage structure is to ensure the high Q value of a single resonant cavity unit, and the design of the connecting seat and the supporting seat is mainly to ensure the close contact between the lower surface of the resonator and the bottom of the cavity, thereby ensuring the connection quality and high Q value of the entire unit resonant cavity. That is, the purpose of the three-stage structure is not to improve the Q value of the TM mode dielectric filter, but to maintain the original Q value without reducing it. Therefore, the above technical solution does not provide any technical inspiration on how to effectively improve the Q value of the TM mode dielectric filter. Summary of the invention

[0003] In view of the defects of the above-mentioned prior art, the purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a cavity hybrid dielectric resonant structure and filter for a filter, which not only has a simple structure but also can meet the requirements of the cavity dielectric filter for higher Q value and smaller volume.

[0004] In order to solve the above technical problems, the present invention adopts a cavity hybrid dielectric resonance structure for a filter, which includes a filter and a dielectric resonance rod arranged in the filter cavity, the dielectric resonance rod includes a coaxially arranged middle resonance unit and an end resonance unit, at least one end resonance unit is arranged at each of the two ends of the middle resonance unit, and the dielectric constant of the middle resonance unit is greater than the dielectric constant of the end resonance unit.

[0005] In a preferred embodiment of the present invention, the numbers of the end resonance units arranged at both ends of the middle resonance unit correspond to each other.

[0006] In a preferred embodiment of the present invention, at least two end resonance units are provided at each end of the intermediate resonance unit, and the dielectric constant of the end resonance unit close to the intermediate resonance unit is greater than the dielectric constant of the end resonance unit far from the intermediate resonance unit.

[0007] In a preferred embodiment of the present invention, the length of the middle resonance unit is greater than the length of the end resonance unit.

[0008] In a preferred embodiment of the present invention, the middle resonance unit and the end resonance unit are in close contact.

[0009] In a preferred embodiment of the present invention, the middle resonance unit and the end resonance unit are formed in a split structure, and the middle resonance unit and the end resonance unit are spliced ​​into an integral structure.

[0010] In a preferred embodiment of the present invention, the dielectric resonance rod is configured as a cylinder, a cube or a cuboid, and the interior thereof is configured to be hollow, or the center thereof is configured to be a through hole or a blind hole.

[0011] In a preferred embodiment of the present invention, the end resonance unit is made of dielectric material.

[0012] In a preferred embodiment of the present invention, the length of the dielectric resonance rod corresponds to the distance from the bottom surface of the filter cavity to the inner end surface of the filter cover plate.

[0013] The present invention also discloses a filter equipped with a mixed dielectric resonance structure, comprising a cavity, a cover plate and a coupling tuning screw, wherein the cover plate is arranged above the cavity, the coupling tuning screw is arranged in the cavity, a plurality of dielectric resonators are arranged in the cavity, and the dielectric resonator is a cavity mixed dielectric resonance structure for a filter, the lower end surface of the mixed dielectric resonance structure is in close contact with the bottom of the cavity, and the upper end surface of the mixed dielectric resonance structure is in close contact with the cover plate.

[0014] The beneficial effects of the present invention are as follows: the present invention has a simple structure and is easy to install and use. By making the dielectric resonant rod into a segmented structure and ensuring that the dielectric constant and length of the dielectric resonant rod in the middle segment are greater than the dielectric constant and length of the dielectric resonant rod in the remaining segments, the single cavity Q value can be effectively improved without changing the remaining structures of the existing resonator. Compared with the traditional TM single dielectric constant resonator, the Q value is improved by more than 50%--200%, and compared with the traditional TM single mode (the traditional TM mode filter single cavity structure generally adopts a dielectric resonator with a single dielectric constant, and a single dielectric resonator is grounded up and down). The volume in the height direction is compressed, but the Q value after volume compression has no obvious advantage over the metal cavity filter of the same volume, so the insertion loss is not reduced even though the filter adopts a dielectric resonator). This method can form dual-mode and multi-mode under a specific shape and size combination, and the volume is greatly reduced by 1 / 3 or even more compared to the TM double-ended grounded single dielectric constant resonator; at the same time, the present invention can adjust the number of end resonant units at both ends of the middle resonant unit as needed while maintaining the total height of the resonant rod, thereby effectively adjusting the size of the Q value; the present invention connects the middle resonant unit and the end resonant unit The one-piece processing and forming of the intermediate resonant unit facilitates the positioning and assembly of the dielectric resonant rod, and the split processing and forming of the intermediate resonant unit and the end resonant unit facilitates the control of the Q value of the dielectric resonant rod; the shape of the intermediate resonant unit and the end resonant unit of the present invention can be a cylinder, a cuboid and a cube, etc., or a combination of the above shapes; in order to meet the requirements of ambient temperature changes and reliability, the material properties of the intermediate resonant unit can be adjusted to perform temperature compensation, so that its electrical performance is more stable under full temperature environment, and in order to enhance the reliability of this structure, the end resonant unit can use elastic materials so that it will not fail due to different expansion coefficients of different materials when the ambient temperature changes rapidly; a filter with a hybrid dielectric resonant structure disclosed in the present invention has a metal inner wall of the cavity, which can be made of aluminum, copper, steel, etc., or can be made of non-metallic materials such as plastics and composite materials, and the inner wall of the cavity can be made conductive by electroplating silver, copper, etc.; after simulation, the electric field intensity is the largest on the side of the cavity. In a long-term high temperature and high power environment, it can be considered to add a heat dissipation device on the side of the cavity, and the heat dissipation teeth can be die-casted into one with the cavity, or a heat sink can be arranged separately outside the cavity to reduce the temperature inside and outside the entire cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an exploded view of a cavity hybrid dielectric resonant structure for a filter (square cavity & cylindrical dielectric rod) according to an embodiment of the present invention;

[0016] Figure 2 This is a front view of a cavity hybrid dielectric resonant structure for a filter (square cavity & cylindrical dielectric rod) according to an embodiment of the present invention;

[0017] Figure 3 It is a cross-sectional view of a cavity hybrid dielectric resonant structure (square cavity & cylindrical dielectric rod) for a filter according to an embodiment of the present invention;

[0018] Figure 4 It is a top view of a cavity hybrid dielectric resonant structure (square cavity & cylindrical dielectric rod) for a filter according to an embodiment of the present invention;

[0019] Figure 5 This is an exploded view of a cavity hybrid dielectric resonant structure for a filter according to an embodiment of the present invention (square cavity & square dielectric rod)

[0020] Figure 6 This is a front view of a cavity hybrid dielectric resonant structure for a filter according to an embodiment of the present invention (square cavity & square dielectric rod);

[0021] Figure 7 It is a cross-sectional view of a cavity hybrid dielectric resonant structure (square cavity & square dielectric rod) for a filter according to an embodiment of the present invention;

[0022] Figure 8 It is a top view of a cavity hybrid dielectric resonant structure for a filter according to an embodiment of the present invention (square cavity & square dielectric rod);

[0023] Fig. 9 This is an exploded view of a cavity hybrid dielectric resonant structure for a filter (cylindrical cavity & cylindrical dielectric rod) according to an embodiment of the present invention;

[0024] Fig.10 This is a front view of a cavity hybrid dielectric resonant structure (cylindrical cavity & cylindrical dielectric rod) for a filter according to an embodiment of the present invention;

[0025] Fig.11 It is a cross-sectional view of a cavity hybrid dielectric resonant structure (cylindrical cavity & cylindrical dielectric rod) for a filter according to an embodiment of the present invention;

[0026] Fig.12 It is a top view of a cavity hybrid dielectric resonant structure (cylindrical cavity & cylindrical dielectric rod) for a filter according to an embodiment of the present invention;

[0027] Fig.13 is an exploded view of a filter equipped with a hybrid dielectric resonant structure according to an embodiment of the present invention;

[0028] In the figure: 1-dielectric resonant rod, 2-middle resonant unit, 3-end resonant unit, 4-cavity, 5-cover plate, 6-coupling tuning screw. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] It can be seen from the structural schematic diagram of a tooling for chamfering and deburring the inner and outer edges of a pipe material shown in the accompanying drawings of the specification of the present invention that the present invention includes a filter and a dielectric resonance rod 1 arranged in the filter cavity, wherein the upper end surface of the dielectric resonance rod 1 is in close contact with the inner end surface of the cover plate of the filter, and the lower end surface of the dielectric resonance rod 1 is in contact with the bottom surface of the cavity of the filter, and the dielectric resonance rod 1 includes a coaxially arranged middle resonance unit 2 and at least two end resonance units 3, the end resonance units 3 are symmetrically arranged relative to the middle resonance unit 2, and at least one end resonance unit 3 is arranged at each of the two ends of the middle resonance unit 2 (the end resonance unit 3 uses the same figure number in the specification, and it should be pointed out that the material, length, and dielectric constant of the end resonance unit 3 can be the same or different), the length of the middle resonance unit 2 is greater than the end resonance unit 3, and the dielectric constant of the middle resonance unit 2 is greater than the dielectric constant of the end resonance unit 3. It should be pointed out that, under the premise of ensuring the middle resonant unit 2 and maintaining the total height of the dielectric resonant rod 1, the end resonant units 3 can be configured at both ends of the middle resonant unit 2 according to the size of the Q value. Generally, the end resonant units 3 at both ends of the middle resonant unit 2 are symmetrically arranged and symmetrically increased (that is, there are an even number of end resonant units 3), but the end resonant unit 3 at one end can also be divided into multiple segments. The above technical solutions all belong to the protection scope of the present invention. At the same time, the dielectric constants of all the end resonant units 3 are smaller than the dielectric constant of the middle resonant unit 2, the lengths of all the end resonant units 3 are smaller than the length of the middle resonant unit 2, and the dielectric constant of the end resonant unit 3 close to the middle resonant unit 2 (among two adjacent end resonant units 3) is greater than the dielectric constant of the end resonant unit 3 far away from the middle resonant unit 2. By analogy, the dielectric constant of the end resonant unit 3 in contact with the bottom of the cavity and the inner surface of the cover plate is the smallest.

[0031] The molding of the dielectric resonance rod 1 includes two schemes: 1. Integrated scheme: the middle resonance unit 2 and the end resonance unit 3 are molded with an integrated structure, that is, they are molded by integral casting using a mold, and the change of the dielectric constant of each unit is formed by adding materials with different dielectric constants at specified positions in the mold.

[0032] 2. Split solution: The middle resonant unit 2 and the end resonant unit 3 are formed by a split structure, and the middle resonant unit 2 and the end resonant unit 3 are connected into an integral structure by splicing (fixed connection is achieved by crimping, bonding, welding, gluing, etc.).

[0033] Whether it is an integrated solution or a split solution, the middle resonant unit 2 and the end resonant unit 3 can be one of the shapes of a cylinder, a cuboid, a cube, etc., and each shape can be solid or hollow. The cavity and the resonant rod shape can be cross-combined, such as a cylindrical dielectric rod installed in a single cuboid or cube cavity; or a cuboid dielectric rod installed in a single cuboid or cube cavity, etc., there is air between the dielectric combination resonant rod and the inner wall of the cavity, and the dielectric rod and the single cavity can form dual-mode and multi-mode under specific size and shape; the dielectric constants of the materials of the middle resonant unit 2 and the end resonant unit 3 are different; the middle resonant unit 2 is a solid cylindrical or hollow sleeve. The end resonant unit 3 is a solid cylindrical or hollow sleeve. The end resonant unit 3 is made of a dielectric material, preferably an elastic material. The length of the dielectric resonant rod 1 corresponds to the distance from the bottom surface of the filter cavity to the inner end surface of the filter cover.

[0034] The present invention also discloses a filter equipped with a mixed dielectric resonance structure, including a cavity 4, a cover plate 5 and a coupling tuning screw 6, wherein the cover plate 5 is arranged above the cavity 4, the coupling tuning screw 6 is arranged in the cavity 4, a plurality of dielectric resonators are arranged in the cavity 4, and the dielectric resonator is a cavity mixed dielectric resonance structure for the filter, the lower end face of the mixed dielectric resonance structure is in close contact with the bottom of the cavity 4, and the upper end face of the mixed dielectric resonance structure is in close contact with the cover plate 5. The inner wall of the cavity 4 is metal, and the material can be aluminum, copper, steel, etc., or non-metallic materials such as plastics and composite materials can be used to make the inner wall of the cavity have conductive properties by electroplating silver, copper, etc. The electric field intensity on the side of the cavity 4 is the largest. In a long-term high temperature and high power environment, it can be considered to add a heat dissipation device on the side of the cavity, and the heat dissipation teeth can be die-casted integrally with the cavity, or a heat sink can be arranged separately outside the cavity to reduce the temperature inside and outside the entire cavity.

[0035] The cover plate structure of the patent of the present invention can overcome the above defects. Through the upper and lower combination structure of two dielectric rods with different dielectric constants, the single-cavity Q value can be greatly improved. Compared with the traditional TM single dielectric constant resonator, the Q value is increased by 50%--200% or more. Compared with the traditional TM single mode, this method can form dual-mode and multi-mode under specific shape and size combinations. Compared with the TM double-ended grounded single dielectric constant resonator, the volume is greatly reduced by 1 / 3 or even more.

[0036] Implementation case 1:

[0037] When the single cavity is rectangular, the dielectric rod is cylindrical, the inner cavity of the single cavity is silver-plated, and the length, width and height are 30mm*30m*23mm respectively, the dielectric constant of the middle resonance unit 2 is 43, the constant constant of the end resonance unit 3 is 1, and the end resonance unit 3 is made of dielectric material with a through hole in the middle, when the frequency is 1800MHz, the Q value is 11424; while the Q value of the single dielectric constant TM mode single cavity filter with the same volume and frequency is 5260, which is more than 100% higher than the Q value of the TM mode single cavity with the same volume and frequency in the traditional solution. And under this structural size, the TM dual mode formed by the cavity hybrid dielectric resonance structure can greatly reduce the volume and improve the Q value when used in the filter in the future, compared with the single dielectric constant TM mode and metal cavity metal resonance rod with the same volume and frequency.

[0038] Implementation case 2:

[0039] When the single cavity is rectangular, the dielectric rod is rectangular, the inner cavity of the single cavity is silver-plated, and the length, width and height are 30mm*30m*23mm respectively, the dielectric constant of the middle resonance unit 2 is 53, the constant constant of the end resonance unit 3 is 1, and the end resonance unit 3 is made of dielectric material, at a frequency of 2000MHz, the Q value is 11386; while the Q value of the single dielectric constant TM mode single cavity filter with the same volume and frequency is 6230, which is more than 90% higher than the Q value of the TM mode single cavity with the same volume and frequency in the traditional solution. And under this structural size, the TM dual mode formed by the cavity hybrid dielectric resonance structure can greatly reduce the volume and improve the Q value when used in the filter in the future, compared with the single dielectric constant TM mode and metal cavity metal resonance rod with the same volume and frequency.

[0040] Implementation case three:

[0041] The single cavity is cylindrical, the dielectric rod is cylindrical, the inner cavity of the single cavity is silver-plated, and the length, width and height are respectively When the dielectric constant of the middle resonance unit 2 is 53 and the constant of the end resonance unit 3 is 1, and the end resonance unit 3 is made of dielectric material, the Q value is 10321 at a frequency of 2000MHz; the Q value of the single dielectric constant TM mode single cavity filter with the same volume and frequency is 4470, which is more than 120% higher than the Q value of the TM mode single cavity with the same volume and frequency in the traditional solution. And under this structural size, the TM dual mode formed by the cavity hybrid dielectric resonance structure can greatly reduce the volume and improve the Q value when used in filters in the future, compared with the single dielectric constant TM mode and metal cavity metal resonance rod with the same volume and frequency.

[0042] It should be understood that the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a technician familiar with the field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A cavity hybrid dielectric resonant structure for a filter, comprising a filter and a dielectric resonant rod (1) arranged in the cavity of the filter, characterized in that: The dielectric resonant rod (1) comprises a coaxially arranged middle resonant unit (2) and an end resonant unit (3); at least two end resonant units (3) are arranged at each of the two ends of the middle resonant unit (2); the dielectric constant of the middle resonant unit (2) is greater than the dielectric constant of the end resonant unit (3); the dielectric constant of the end resonant unit (3) coaxially arranged on the same axis close to the middle resonant unit (2) is greater than the dielectric constant of the end resonant unit (3) coaxially arranged on the same axis away from the middle resonant unit (2); and the length of the middle resonant unit (2) is greater than the length of the end resonant unit (3) coaxially arranged on the same axis.

2. The cavity hybrid dielectric resonant structure for a filter according to claim 1, characterized in that: The number of the end resonance units (3) arranged at both ends of the middle resonance unit (2) corresponds to each other.

3. The cavity hybrid dielectric resonant structure for a filter according to claim 1, characterized in that: The middle resonance unit (2) and the end resonance unit (3) are in close contact.

4. The cavity hybrid dielectric resonant structure for a filter according to claim 1, characterized in that: The middle resonance unit (2) and the end resonance unit (3) are formed by a split structure, and the middle resonance unit (2) and the end resonance unit (3) are spliced ​​into an integral structure.

5. The cavity hybrid dielectric resonant structure for a filter according to claim 1, characterized in that: The dielectric resonance rod (1) is configured as a cylinder, a cube or a cuboid, and its interior is configured to be hollow, or its center is configured to be a through hole or a blind hole.

6. The cavity hybrid dielectric resonant structure for a filter according to claim 1, characterized in that: The end resonance unit (3) is made of dielectric material.

7. The cavity hybrid dielectric resonant structure for a filter according to claim 1, characterized in that: The length of the dielectric resonance rod (1) corresponds to the distance from the bottom surface of the filter cavity to the inner end surface of the filter cover plate.

8. A filter, comprising a cavity (4), a cover plate (5) and a coupling tuning screw (6), wherein the cover plate (5) is arranged above the cavity (4), the coupling tuning screw (6) is arranged in the cavity (4), and a plurality of dielectric resonators are arranged in the cavity (4), characterized in that: The dielectric resonator is a cavity hybrid dielectric resonant structure for a filter as claimed in any one of claims 1 to 7, wherein the lower end surface of the cavity hybrid dielectric resonant structure for a filter is in close contact with the bottom of the cavity (4), and the upper end surface of the hybrid dielectric resonant structure is in close contact with the cover plate (5).

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