WO2013016920A1 - Resonant cavity and filter having the resonant cavity - Google Patents

Abstract

Provided is a resonant cavity, having the interior being a cavity. At least one metamaterial lamella is placed in the cavity. Each metamaterial lamella comprises a substrate made of a non-metallic material and a man-made microstructure adhering to a surface of the substrate. The man-made microstructure is a structure that is formed of a thread made of an electrically conductive material and has a geometric pattern. When the resonant cavity, and after the metamaterial lamella is added therein, the resonant frequency of the resonant cavity can be decreased obviously, thereby miniaturizing the resonant cavity. Also provided is a filter having the resonant cavity.

Description

 Resonant cavity and filter having the same

 This application claims the priority of the Chinese Patent Application entitled "A Resonant Cavity" submitted to the China Patent Office on July 29, 2011, with the application number of 201110216460.4, and submitted to the Chinese Patent Office on August 16, 2011. Priority for the Chinese patent application entitled "A Resonant Cavity", 201110233307.2, filed on July 29, 2011, Chinese Patent Office, Application No. 201110216572.X, Chinese patent entitled "A Filter" Priority of the application, the entire contents of which are incorporated herein by reference. Technical field

 The present invention relates to the field of wireless communications, and more particularly to a resonant cavity and a filter having the same. Background technique

 In microwave devices, cavity filters are a very important device. The cavity filter is composed of several microwave resonators, each of which has an arbitrary shape of a cavity surrounded by a conductive wall (or a magnetic conductive wall), and can form an electromagnetically oscillated medium region therein, which has a storage Electromagnetic energy and the characteristics of selecting a certain frequency signal.

 The resonant cavity is a resonant component that operates at a microwave frequency. The resonant frequency of the microwave resonant cavity depends on the volume of the cavity. Generally, the larger the resonant cavity volume, the lower the resonant frequency, and the larger the resonant cavity volume, the higher the resonant frequency. How to reduce the resonant frequency of the resonant cavity without increasing the size of the resonant cavity is of great significance for the miniaturization of the resonant cavity. Summary of the invention

 The technical problem to be solved by the present invention provides a d, a volume of a resonant cavity and a filter.

 The invention provides a resonant cavity, the inside of which is a cavity, and at least one metamaterial sheet is placed inside the cavity, and each of the metamaterial sheets comprises a substrate made of a non-metal material and an artificial material attached to the surface of the substrate. Microstructure, the artificial microstructure is a geometrically patterned structure composed of wires of a conductive material.

There are a plurality of the super-material sheets, and the super-material sheets are arranged in parallel with each other. There are a plurality of the super-material sheets, and the surfaces of the super-material sheets are integrally connected in contact with each other. Wherein, a wave-transparent material is placed between adjacent two super-material sheets.

 Wherein, the resonant cavity further includes a first metamaterial plate, an input end and an output end, the first metamaterial plate is composed of the at least one metamaterial sheet, the first metamaterial plate is to be the cavity The input end and the output end are respectively located in two chambers, and the input end and the output end are respectively mounted on inner walls of both sides of the cavity.

 Wherein, the plurality of metamaterial sheets are provided, and each of the two chambers is respectively provided with a second metamaterial board, and the two second metamaterial boards are respectively coupled with the input end and the output end. The second metamaterial sheet is composed of at least one of the metamaterial sheets.

 The resonant cavity further includes a tuning screw mounted on the inner wall of the top of the cavity, between the input end and the output end, and located directly above the first metamaterial board.

 Wherein, the artificial microstructure is a structure in which a wire is spirally wound.

 Wherein, a cavity is disposed in the cavity, and the metamaterial sheet layer is fixed on the support.

 Wherein, the support is made of a wave permeable material.

 Wherein the socket is provided with a slot, and the metamaterial sheet layer is inserted into the slot. Wherein, the artificial microstructure is a cross shape or a cross shape.

 Wherein, the cross-shaped derivative has four identical branches, and any of the branches is rotated 90 degrees, 180 degrees, and 270 degrees in a row as a center of rotation, and then coincides with the other three branches in turn.

 One end of each branch is connected to the other three branches at the same end, and the other end is a free end, and at least one bent portion is disposed between the two ends.

 Wherein, the free end of the branch is connected with a line segment.

 Wherein the artificial microstructure is made of metal.

 The resonant cavity according to any one of claims 1 to 6, wherein the artificial microstructure is composed of a non-metallic conductive material.

 The material of the substrate is ceramic, polytetrafluoroethylene, epoxy resin, ferroelectric material, ferrite material, ferromagnetic material or FR-4.

 Accordingly, embodiments of the present invention also provide a filter including at least one of the above-described resonant cavities.

The implementation of the resonant cavity of the present invention has the following beneficial effects: The use of the resonant cavity of the present invention, which is added to the metamaterial sheet, facilitates miniaturization of the resonant cavity and the filter. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in the claims Other drawings may also be obtained from these drawings without the inventive labor.

 1 is a schematic view of a resonant cavity of a first embodiment of the present invention;

 2 is a schematic structural view of a metamaterial sheet of the resonator shown in FIG. 1;

 3 is a schematic structural view of a derivative structure in which an artificial microstructure is an I-shaped shape;

 Figure 4 is a schematic view showing the structure of an artificial microstructure having a cross shape;

 5 to FIG. 8 are schematic structural views showing the artificial microstructures of the other four cross-shaped derivations; FIG. 9 is a schematic structural view of the resonant cavity of the second embodiment of the present invention;

 Figure 10 is a schematic view showing the artificial microstructure being the first spiral structure;

 Figure 11 is a schematic view showing the artificial microstructure being a second spiral structure;

 Figure 12 is a schematic view showing the artificial microstructure as a third spiral structure;

 Figure 13 is a schematic view showing the structure of a resonant cavity in accordance with a third embodiment of the present invention;

 Figure 14 is a simulation diagram when the resonant cavity is not placed in the first metamaterial plate;

 Figure 15 is a simulation diagram after the first metamaterial plate is added to the resonant cavity;

 Fig. 16 is a view showing the configuration of a filter of a fourth embodiment of the present invention. Specific embodiment

 The invention relates to a resonant cavity, which mainly refers to a microwave resonant cavity. Referring to Fig. 1, a resonant cavity provided by a first embodiment of the present invention has a cavity 8 filled with a medium inside. The medium filled in the cavity 8 of the present invention is a metamaterial.

As shown in FIG. 1, the metamaterial includes at least one metamaterial sheet 1. When there is one of the metamaterial sheets 1, it can be directly fixed into the cavity 8. When there are a plurality of super-material sheet layers 1, the surfaces of the plurality of meta-material sheets 1 are bonded in contact with each other, and a wave-transparent material such as foam may be placed between adjacent two super-material sheets 1 to separate them. open. A cavity can be placed in the cavity 8, and a socket is arranged on the support, and the whole of the plurality of metamaterial sheets 1 is inserted into the slot so that they are placed in parallel with each other. The support is preferably a wave permeable material such as foam. The metamaterial sheet layer 1 includes a flat substrate 3 and an artificial microstructure 2 attached to the surface of the substrate 3. The substrate 3 is made of a non-metallic material such as polytetrafluoroethylene, epoxy resin, ceramics, ferroelectric material, ferrite material, ferromagnetic material, FR-4 material, and the like. The artificial microstructure 2 is a structure of a certain geometric pattern composed of at least one wire on the surface of the substrate 3, such as a "work" shape, an open resonance ring, and the like. The wires of the artificial microstructure 2 are made of a conductive material, usually a metal such as silver, copper, etc., and may also be made of other non-metallic conductive materials such as ITO. The wire has a line width of less than 1 mm, preferably a processable minimum line width of, for example, 0.1 mm; the thickness of the wire is 4 inches, usually the thickness of the plating layer, typically less than 0.1 mm in the present invention, and the column: 3⁄4 port 0.018 mm.

 There are many cases in the geometric pattern of the artificial microstructure 2, such as an I-shape, which includes a first metal wire 201 that is in line and two that are connected at both ends of the first metal wire 201 and are vertically divided by the first metal wire 201. The second metal wire 202; such an I-shaped artificial microstructure can be further derivatized to obtain an I-shaped derivative shape, as shown in FIG. 3, which includes, in addition to the first and second metal wires, respectively connected to each A third metal line 203 at both ends of the second metal line 202 and vertically divided by the second metal line 202, and a fourth metal line 204 respectively connected to each of the third metal lines 203 and vertically divided by the third metal line 203 , and so on, continue to derive.

 Similarly, the artificial microstructure 2 of the present invention may also be a cross-shaped derivative shape including two first metal wires 201 that are vertically and halved to form a cross, and are further connected to the ends of each of the first metal wires 201, respectively. And a derivative shape formed by the second metal line 202 vertically divided by the first metal line 201 is as shown in FIG. 2; further, when the artificial microstructure is divided into the first and second metal lines, it may further comprise a third metal line 203 at both ends of the second metal line 202 and vertically divided by the second metal line 202, and a first line respectively connected to each of the third metal lines 203 and vertically divided by each of the third metal lines 203 The four metal wires 204 are structured as shown in FIG. Other derivatives can also be obtained by analogy.

 In other embodiments of the cross-shaped derivative shape, the artificial microstructure 2 includes four identical branches 210, and any of the branches 210 is rotated 90 degrees, 180 degrees, and 270 degrees in sequence with a point as a center of rotation, respectively. The three branches 210 coincide. Therefore, such an artificial microstructure 2 is an isotropic structure, and its response characteristics to electromagnetic waves are the same in all directions of the plane in which it is located, and the above-described cross-shaped derivative artificial microstructures as shown in FIGS. 2 and 4 also have such a structure. Characteristics. Of course, in the above embodiment, the four branches 210 may be connected in one end to be integrated.

As shown in FIG. 5 to FIG. 8 , one end of each branch 210 is connected to the other three branches 210 at the same end, and the other end is a free end, and at least one bent portion is disposed between the two ends. The bend here can be a right angle The bending, as shown in Fig. 5, may also be a sharp corner bending as shown in Fig. 6 and Fig. 7, and may also be a rounded corner, as shown in Fig. 8. The outer portion of the free end may also be connected with a straight line segment. As shown in Figs. 7 and 8, the end point of the free end is preferably connected to the midpoint of the line segment.

 Due to the existence of the artificial microstructure 2 made of a conductive material, the metamaterial sheet has a high dielectric constant, and after being incorporated into the cavity, the resonant frequency of the cavity can be significantly reduced, so that the filter composed of a plurality of resonators is formed. Miniaturization is possible.

 For example, the cavity shown in Figure 1 is a 20mm 20mm 20mm cube, the metamaterial sheet is 15mm 12mm 1.018mm, a total of 12 metamaterial sheets, the substrate is ceramic, the thickness is 1mm, and each artificial microstructure is as shown in Figure 1. The cross-shaped derivative shown in Fig. 2 has a size of 3 mm x 3 mm, and each of the substrates is arranged with 4 x 5 human microstructures. It can be seen from the simulation that the first and second resonant frequencies are both 0 and the third resonant frequency is 1.9699 GHz. The resonant frequency of the cavity is 10 GHz. It can be seen that after adding the metamaterial structure, its resonant frequency is reduced to 1.9699 GHz. In addition, there are many different modes in the resonant cavity, corresponding to different resonant frequencies. According to the embodiment of the present invention, the first and second resonant frequencies are 0, indicating that the low-order modes are suppressed, and the higher-order modes are excited, and the more The higher the Q mode, the higher the Q value means that the loss of the cavity is small. This is also one of the advantages of the present invention. It can be seen that, by using the resonant cavity of the present invention, after adding the super-material layer 1, the resonant frequency can be significantly reduced, which is advantageous for miniaturization of the filter.

 Referring to FIG. 9, a resonant cavity 200 according to a second embodiment of the present invention is provided. The resonant cavity 200 is substantially the same as the resonant cavity of the first embodiment, except that the resonant cavity 200 is also in the cavity. A tuning screw 106 is mounted on the top inner wall of the 104, and an input end 150 and an output end 105 are mounted on the inner walls of both sides of the cavity 104. The metamaterial sheet layer 101a constitutes a first metamaterial sheet 101. The first metamaterial sheet 101 includes five metamaterial sheets 101a. The first metamaterial sheet 101 is placed on the inner wall of the bottom of the cavity 104. Since the first metamaterial sheet 101 has a certain area, the inner space of the cavity 104 is divided into two, that is, the original one cavity 104 is divided into two. a chamber. Since the first metamaterial sheet 101 is disposed opposite the tuning screw 106 and spaced apart from the tuning screw 106, the two chambers are not completely closed, but the two chambers pass through the first metamaterial. The spacing between the plate 101 and the tuning screw 106 is in communication, the input end 150 and the output end 105 are respectively located in the two chambers, and the wires of the two pass through the first metamaterial sheet 101.

At this time, since the single cavity is approximately divided into "dual cavity", the transmission characteristics of the cavity can reach the effect of bandwidth. While realizing the bandwidth, in order to reduce the volume of the resonant cavity, the resonant frequency of the resonant cavity should also be minimized, which can be achieved by utilizing the characteristics of the first metamaterial plate. The metamaterial sheet layer 101a can exhibit special, even natural, properties that are difficult to achieve, such as higher dielectric constant, negative magnetic permeability, negative refractive index, and the like. The metamaterial sheet layer 101a in this embodiment enables the resonant cavity to have a resonance bandwidth effect.

 When the artificial microstructure of the metamaterial sheet 101a is a spiral as shown in Figs. 10-12, a high dielectric constant characteristic can be attained. Fig. 10 is a clockwise, counterclockwise spiral at both ends of a wire, Fig. 11 is a synchronous spiral of a wire folded in half, and Fig. 12 is a structure in which four identical spirals are connected at one end. Such a spiral structure enables the first metamaterial block to have a high dielectric constant, thereby functioning as a low frequency point.

 In order to further increase the frequency down characteristic of the cavity, as shown in FIG. 13, in the third embodiment, the resonator of the present invention is also at the input terminal 150 and the output terminal 105 in addition to all the components and structures as shown in FIG. The ends are respectively contacted with a second metamaterial plate 107, and the two second metamaterial plates 107 are respectively located in the two chambers, and are not in contact with the first metamaterial plate 101. At this time, adjusting the tuning screw 106 changes the coupling form in the cavity, thereby making the frequency and the differential loss adjustable.

 The second metamaterial sheet 107, like the first metamaterial sheet 101, is also composed of at least one metamaterial sheet, which may be the same substrate and artificial microstructure as the first metamaterial sheet 101 described above, or may be different, but The size should be smaller than the first metamaterial sheet 101.

 Through simulation, it is found that the resonant cavity shown in FIG. 9 is used when the first metamaterial plate 101 is not placed, and its S-parameter simulation diagram is shown in FIG. 14 , which shows that it has only one resonant frequency and is about 9.8 GHz; When it is placed in the first metamaterial sheet 101 and the first metamaterial sheet 101 includes five super material sheets as shown in FIG. 2, the obtained S-parameter simulation map is as shown in FIG. 15, which is known from the figure. After the metamaterial, the above resonator forms a passband from 6.275 GHz to 6.324 GHz with a bandwidth of about 50 MHz. Obviously, the resonant frequency is also significantly lower than the previous 9.8 GHz. Therefore, with the resonator of the present invention incorporating the first supermaterial plate, a bandwidth which can be formed by combining at least two resonators can be formed, and the resonance frequency can also be lowered.

 The cavity in this embodiment can realize the bandwidth by relying on a single cavity, and can effectively reduce the number of resonators in the filter under the same bandwidth, thereby effectively reducing the volume of the filter.

 Please refer to FIG. 16, which is a filter according to a fourth embodiment of the present invention.

The filter of this embodiment mainly refers to a microwave filter. As shown in FIG. 16, the inside is at least one resonant cavity 208 of the first embodiment. Of course, in other embodiments, the resonant cavity 208 can also adopt the resonant cavity of the second or third embodiment. The resonant cavity 208 is provided with an input end and an output end on both sides. A total of 14 sheets of metamaterial sheets 201 are bonded to each other, and the input end and the output end are respectively abutted on both side surfaces of the metamaterial sheet layer 201. Of course, the input and output terminals may also not be in contact with the metamaterial sheet.

 The metamaterial sheet 201 can increase the bandwidth of the resonant cavity, thereby reducing the number of filter resonators, thereby achieving miniaturization of the filter.

 For example, the resonator shown in Figure 16 is a 20mm 20mm 20mm cube, the metamaterial sheet is 7mm X 5.6mm X 1.018mm, a total of 6 metamaterial sheets, the substrate is FR-4 epoxy, and the thickness is 1mm. Each of the artificial microstructures has a cross-shaped derivative shape as shown in Fig. 2, and has a size of 1.4 mm X 1.4 mm, and each of the substrates is arranged in an array of 20 human microstructures. It can be seen from the simulation that the first and second resonant frequencies are all 0, and the third and fourth resonant frequencies are 3.810 GHz and 3.861 GHz, respectively, which constitute a bandwidth exceeding at least 50 MHz. When the super-material layer is not placed in the same cavity, the first resonant frequency is 6.100 GHz, the second resonant frequency is 8.360 GHz, the third resonant frequency is 9.938 GHz, and the fourth resonant frequency is 9.938 GHz. The second resonant frequency differs by more than 2 GHz and cannot form a wide frequency band. In addition, there are many different modes in the resonant cavity, corresponding to different resonant frequencies. With the embodiment of the present invention, the first and second resonant frequencies are 0, indicating that the low-order modes are suppressed, the higher-order modes are excited, and the higher-order modes are excited. The higher the Q value, the higher the Q value means that the loss of the cavity is small. This is also one of the advantages of the present invention.

 It can be seen that the filter of the present invention, when added to the metamaterial layer 201, can pull in multiple resonant frequencies, resulting in a wide bandwidth of a single resonant cavity, and thus can withstand a high power filter, that is, a single The cavity high power filter can therefore achieve miniaturization of the filter, while also having the advantage of suppressing the loss of the low order mode.

 The above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and the equivalent changes made by the claims of the present invention are still within the scope of the present invention.

Claims

Rights request

A cavity having a cavity inside, wherein at least one metamaterial sheet is placed inside the cavity, each of the metamaterial sheets comprising a substrate made of a non-metal material and attached to the surface of the substrate The artificial microstructure on the artificial microstructure is a geometrically patterned structure composed of wires of a conductive material.

 The resonant cavity according to claim 1, wherein the plurality of metamaterial sheets are plural, and each of the metamaterial sheets is spaced apart from each other in parallel.

 3. The resonant cavity according to claim 1, wherein the plurality of metamaterial sheets have a plurality of layers, and the surfaces of the super material sheets are integrally connected in contact with each other.

 4. The resonant cavity of claim 3, wherein a wave permeable material is placed between adjacent ones of the two metamaterial sheets.

 5. The resonant cavity of claim 1 , wherein the resonant cavity further comprises a first metamaterial plate, an input end and an output end, the first metamaterial plate being composed of the at least one metamaterial sheet The first meta-material board divides the cavity into two communicating chambers, wherein the input end and the output end are respectively located in two chambers, and the input end and the output end are respectively installed in the chamber On the inner walls on both sides of the cavity.

 The resonant cavity according to claim 5, wherein the plurality of metamaterial sheets are provided, and each of the two chambers is respectively provided with a second metamaterial board, and the two second super A material plate is coupled to the input end and the output end, respectively, and the second metamaterial plate is composed of at least one of the metamaterial sheets.

 The resonant cavity according to claim 5 or 6, wherein the resonant cavity further comprises a tuning screw, and the tuning screw is mounted on an inner wall of the top of the cavity, at the input end and the output end Between, and located directly above the first metamaterial board.

 The resonant cavity according to claim 5 or 6, wherein the artificial microstructure is a structure in which a wire is spirally wound.

 The resonant cavity according to any one of claims 1 to 6, wherein a cavity is disposed in the cavity, and the metamaterial sheet is fixed on the support.

 10. A resonant cavity according to claim 9 wherein the support is made of a wave permeable material.

11. The resonant cavity of claim 9, wherein the holder is provided with a slot into which the metamaterial sheet layer is inserted.

The resonant cavity according to any one of claims 1 to 6, wherein the artificial microstructure is a deformed shape of an I-shape or an I-shape.

 The resonant cavity according to any one of claims 1 to 6, wherein the artificial microstructure is a cruciform or cruciform derivative.

 14. The resonant cavity according to claim 13, wherein the derivative of the cross shape has four identical branches, and any of the branches rotates 90 degrees, 180 degrees, and 270 degrees in sequence with a point of rotation. After that, they overlap in the other three branches.

 15. The resonant cavity according to claim 14, wherein one end of each branch is connected to the other three branches at the same end, and the other end is a free end, and at least one bent portion is disposed between the two ends.

 16. The resonant cavity of claim 15 wherein the free end of the branch is connected to a line segment.

 The resonator according to any one of claims 1 to 6, wherein the artificial microstructure is made of metal.

 The resonant cavity according to any one of claims 1 to 6, wherein the artificial microstructure is composed of a non-metallic conductive material.

 The resonant cavity according to any one of claims 1 to 6, wherein the material of the substrate is ceramic, polytetrafluoroethylene, epoxy resin, ferroelectric material, ferrite material, ferromagnetic material or FR-4.

 A filter comprising at least one resonant cavity according to any of claims 1-19.