A cavity metal dielectric rod hybrid resonance structure and filter

Abstract

The present invention discloses a cavity metal dielectric rod hybrid resonance structure and filter, which includes a metal single cavity and a dielectric resonance rod arranged in the metal single cavity, wherein the dielectric resonance rod includes a coaxially arranged middle metal resonance unit and an end dielectric resonance unit, and at least one end dielectric resonance unit is arranged at each of the two ends of the middle metal resonance unit. The present invention has a simple structure and is easy to install and use. The dielectric resonance rod is made into a segmented structure, and the middle metal resonance unit is designed as a metal material, and the end dielectric resonance unit is designed as a dielectric material. In addition, a coaxial metal cavity is added to the existing traditional cavity filter, so that the height size of the filter installed with the present invention is compressed by more than 1 / 3 relative to the size of the filter in the prior art, and at the same time, the filter frequency can be effectively reduced significantly without increasing the 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 communication, and in particular to a cavity metal dielectric rod hybrid resonant structure and a filter. Background Art

[0002] With the rapid development of wireless mobile communications, the signal coverage range of low-frequency bands is larger, and the signal diffraction performance is also better. The requirements for miniaturization of communication equipment at low frequencies are increasing, especially in the field of low-frequency filters. Traditional filters generally use a cavity plus a coaxial metal resonant rod. However, due to the low frequency of such filters, when the frequency is below 700MHz, the volume is large due to the wavelength. When a spiral resonator is used, although the volume can be compressed, the Q value of a single cavity is generally low, resulting in excessive insertion loss of the filter. At the same time, the products in the prior art cannot achieve a low filtering frequency while maintaining the volume of the filter without increasing, so that it can be used on private networks or special low-frequency filter products. 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 low-frequency filter to 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 metal single cavity and a dielectric resonance rod arranged in the metal single cavity, the dielectric resonance rod includes a coaxially arranged middle metal resonance unit and an end dielectric resonance unit, and at least one end dielectric resonance unit is arranged at each of the two ends of the middle metal resonance unit.

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

[0006] In a preferred embodiment of the present invention, at least two end dielectric resonance units are provided at each end of the intermediate metal resonance unit.

[0007] In a preferred embodiment of the present invention, the middle metal resonance unit and the end dielectric resonance unit are in close contact.

[0008] In a preferred embodiment of the present invention, the middle metal resonance unit and the end dielectric resonance unit are formed in a split structure, and the middle metal resonance unit and the end dielectric resonance unit are spliced ​​into an integral structure.

[0009] In a preferred embodiment of the present invention, the metal single cavity or the dielectric resonant rod is configured as a cylinder, a cube or a cuboid, and the interior of the dielectric resonant rod is configured to be hollow, or the center is configured to be a through hole or a blind hole.

[0010] In a preferred embodiment of the present invention, the middle metal resonance unit is made of metal material, and the end dielectric resonance unit is made of dielectric material.

[0011] 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.

[0012] The present invention also discloses a filter equipped with a cavity metal dielectric rod hybrid 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, and a plurality of dielectric resonators are arranged in the cavity, characterized in that: the dielectric resonator is a cavity metal dielectric rod hybrid resonance structure, the lower end surface of the cavity metal dielectric rod hybrid resonance structure is in close contact with the bottom of the cavity, and the upper end surface of the cavity metal dielectric rod hybrid resonance structure is in close contact with the cover plate.

[0013] The beneficial effects of the present invention are as follows: the present invention has a simple structure and is easy to install and use. The present invention makes the dielectric resonance rod into a segmented structure, designs the middle metal resonance unit as a metal material, designs the end dielectric resonance unit as a dielectric material, and adds a coaxial metal cavity to the existing traditional cavity filter, so that the height size of the filter installed with the present invention is compressed by more than 1 / 3 relative to the size of the filter in the prior art. At the same time, the filter frequency can be effectively reduced while the volume is kept unchanged, so that the filter can be used in a dedicated network or a special low-frequency filter product. The higher the dielectric constant of the end dielectric resonance unit of the present invention is, the more the height size is compressed. The larger the dielectric rod is, the thinner the dielectric rod is, the lower the frequency is, and the Q value does not drop significantly with the reduction of the cavity size; at the same time, the present invention can adjust the number of end dielectric resonance units at both ends of the middle metal resonance unit as needed while maintaining the total height of the resonance rod, thereby effectively adjusting the size of the Q value; the present invention facilitates the positioning and assembly of the dielectric resonance rod by integrally processing the middle metal resonance unit and the end dielectric resonance unit, and facilitates the control of the Q value of the dielectric resonance rod by separately processing the middle metal resonance unit and the end dielectric resonance unit; the shape of the middle metal resonance unit and the end dielectric resonance unit of the present invention can be a cylinder, a cuboid, a cube, etc. , or a combination of the above shapes, the shape of the metal single cavity can also be a cylinder, a cuboid and a cube, the metal single cavity and the resonance rod shape can be cross-combined, such as a cylindrical dielectric rod installed in a cuboid or cube single cavity; or a cuboid dielectric rod installed in a cuboid or cube single cavity, etc., there is air between the dielectric combination resonance rod and the inner wall of the cavity, and the top or bottom of the metal rod can be designed to be a flange shape, which can be applied to low frequency; in order to meet the requirements of ambient temperature changes and reliability, the present invention can adjust the material properties of the intermediate metal resonance unit for temperature compensation, so that its electrical performance is more stable under full temperature environment, in order to enhance the reliability of this structure, the end dielectric The 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; the filter disclosed in the present invention is equipped with a mixed dielectric resonant structure, and the inner wall of the cavity is metal, which can be made of 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 conductive by electroplating silver, copper, etc.; simulation shows that 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. The heat dissipation teeth can be die-casted together 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

[0014] Figure 1 This is an exploded view of a cavity metal dielectric rod hybrid resonance structure according to an embodiment of the present invention;

[0015] Figure 2 This is a front view of a cavity metal dielectric rod hybrid resonance structure according to an embodiment of the present invention;

[0016] Figure 3 is a cross-sectional view of a cavity metal dielectric rod hybrid resonance structure according to an embodiment of the present invention;

[0017] Figure 4 is a top view of a cavity metal dielectric rod hybrid resonance structure according to an embodiment of the present invention;

[0018] Figure 5 This is an exploded view of a filter with a cavity metal dielectric rod hybrid resonance structure installed in an embodiment of the present invention

[0019] Figure 6 This is a front view of a filter with a cavity metal dielectric rod hybrid resonance structure installed in an embodiment of the present invention;

[0020] Figure 7 is a cross-sectional view of a filter equipped with a cavity metal dielectric rod hybrid resonance structure according to an embodiment of the present invention;

[0021] In the figure: 1- dielectric resonant rod, 2- middle metal resonant unit, 3- end dielectric resonant unit, 4- cavity, 5- cover plate, 6- coupling tuning screw, 7- metal single cavity. DETAILED DESCRIPTION

[0022] 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.

[0023] It can be seen from the schematic diagram of a cavity metal dielectric rod hybrid resonance structure shown in the accompanying drawings of the specification of the present invention that the present invention includes a metal single cavity, and a dielectric resonance rod 1 arranged in the metal single 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 metal single cavity, and the lower end surface of the dielectric resonance rod 1 is in contact with the cavity bottom surface of the metal single cavity, and the dielectric resonance rod 1 includes a coaxially arranged middle metal resonance unit 2 and at least two end dielectric resonance units 3, the end dielectric resonance units 3 are symmetrically arranged relative to the middle metal resonance unit 2, at least one end dielectric resonance unit 3 is arranged at each of the two ends of the middle metal resonance unit 2, and the length of the middle metal resonance unit 2 is greater than the end dielectric resonance unit 3. It should be pointed out that, under the premise of ensuring the middle metal resonance unit 2 and maintaining the total height of the dielectric resonance rod 1, end dielectric resonance units 3 can be configured at both ends of the middle metal resonance unit 2 according to the size of the Q value. Generally, the end dielectric resonance units 3 located at both ends of the middle metal resonance unit 2 are symmetrically arranged and symmetrically increased, but the end dielectric resonance 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, under the premise of maintaining the middle metal resonance unit 2, different numbers of end dielectric resonance units 3 with different dielectric constants can be added on the basis of the end dielectric resonance unit 3. The added end dielectric resonance units 3 are symmetrically increased up and down (under the premise of maintaining the total height of the resonance rod, the middle metal resonance unit 2 is always kept in the middle position of the resonance rod, and the remaining end dielectric resonance units 3 are symmetrically located at the upper and lower positions of the middle metal resonance unit 2), and in the metal-dielectric hybrid resonance rod, the dielectric constant of the added end dielectric resonance unit 3 is smaller than the dielectric constant of the original end dielectric resonance unit 3. By analogy, the dielectric constant of the end dielectric resonance unit 3 in contact with the bottom of the metal single cavity and the inner surface of the cover plate is the smallest. In a preferred embodiment of the present invention, the end dielectric resonant units 3 arranged at both ends of the middle metal resonant unit 2 are arranged symmetrically with respect to the middle metal resonant unit 2 .

[0024] The molding of the dielectric resonance rod 1 includes two schemes: 1. Integrated scheme: the middle metal resonance unit 2 and the end dielectric 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.

[0025] 2. Split-type solution: The middle metal resonance unit 2 and the end dielectric resonance unit 3 are formed by a split-type structure, and the middle metal resonance unit 2 and the end dielectric resonance unit 3 are connected to form an integral structure by splicing.

[0026] Whether it is an integrated solution or a split solution, the middle metal resonance unit 2 and the end dielectric resonance 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 resonance 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 resonance 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 metal resonance unit 2 and the end dielectric resonance unit 3 are different; the middle metal resonance unit 2 is a solid cylindrical or hollow sleeve. The end dielectric resonance unit 3 is a solid cylindrical or hollow sleeve. The end dielectric resonance unit 3 is made of dielectric material, preferably elastic material. 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.

[0027] The present invention also discloses a filter with a hybrid dielectric resonant 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, and a plurality of dielectric resonators are arranged in the cavity 4, wherein the dielectric resonator is a cavity metal dielectric rod hybrid resonance structure, wherein the lower end surface of the cavity metal dielectric rod hybrid resonance structure is in close contact with the bottom of the cavity 4, and the upper end surface of the cavity metal dielectric rod hybrid resonance structure is in close contact with the cover plate 5. The inner wall of the cavity 4 is metal, and the material may be aluminum, copper, steel, etc., or non-metallic materials such as plastic and composite materials may 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 may be considered to add a heat dissipation device on the side of the cavity, and a heat dissipation tooth may be die-casted integrally with the cavity, or a heat sink may be separately arranged outside the cavity to reduce the temperature inside and outside the entire cavity.

[0028] The cover plate structure of the patent of the present invention can overcome the above defects. Through the combined structure of metal rods and dielectric rods, it can effectively reduce the volume of the filter while improving the single-cavity Q value. Compared with the traditional TM single dielectric constant resonator, the Q value is increased by more than 10%, and compared with the traditional TM single mode, this method can form dual-mode and multi-mode under a specific shape and size combination. Compared with the TM double-ended grounded single dielectric constant resonator, the volume is greatly reduced by 1 / 3 or even more; at the same time, it can greatly reduce the filter frequency while keeping the volume unchanged, in dedicated networks or special low-frequency filter products.

[0029] Specific implementation case: When the size is 20*20*30, the traditional coaxial metal single cavity, in low-frequency applications, generally uses a metal resonant rod with a flange to achieve frequency reduction. If the frequency needs to be further reduced, it is also turned down on the basis of the flat flange to further reduce the frequency. At present, under this volume, the lowest frequency simulated in the conventional way can only reach 763MHz. Now a cavity metal dielectric resonant rod hybrid structure is adopted. The dielectric constant of the middle metal resonance unit 2 and the end dielectric resonance unit 3 is 1, the diameter is 10mm, the thickness is 0.5mm, the height of the metal resonance rod is 29mm, the diameter is 10mm, the simulation frequency is 300M, and the Q value is 1100. Compared with the traditional metal single cavity, the frequency is reduced by nearly 400MHz on the basis of the original frequency. If the straight rod diameter is changed to 4mm on the basis of metal resonance, and a flange with a diameter of 19mm is added, the simulation frequency can reach 125MHz and the Q value is 774. Therefore, through the new cavity metal dielectric resonant rod hybrid structure, the filter frequency can be greatly reduced without increasing the volume. This solution can fully meet the application needs of private networks or special low-frequency filter products.

[0030] 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 metal-dielectric rod hybrid resonance structure, comprising a metal single cavity and a dielectric resonance rod (1) arranged in the metal single cavity, characterized in that: The dielectric resonance rod (1) comprises a coaxially arranged middle metal resonance unit (2) and an end dielectric resonance unit (3), and at least two end dielectric resonance units (3) are arranged at each of the two ends of the middle metal resonance unit (2).

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

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

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

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

6. The cavity metal dielectric rod hybrid resonance structure 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.

7. A filter having a cavity metal dielectric rod hybrid resonance structure, 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 metal dielectric rod hybrid resonance structure as described in any one of claims 1 to 6, wherein the lower end surface of the cavity metal dielectric rod hybrid resonance structure is in close contact with the bottom of the cavity (4), and the upper end surface of the cavity metal dielectric rod hybrid resonance structure is in close contact with the cover plate (5).

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