WO2013044562A1

WO2013044562A1 - Resonant cavity, filter with the same

Info

Publication number: WO2013044562A1
Application number: PCT/CN2011/083894
Authority: WO
Inventors: 刘若鹏; 栾琳; 刘京京; 马伟涛; 张伟
Original assignee: 深圳光启高等理工研究院; 深圳光启创新技术有限公司
Priority date: 2011-09-30
Filing date: 2011-12-13
Publication date: 2013-04-04
Also published as: CN103035999B; CN103035999A

Abstract

The present invention provide a resonant cavity, including a case with an inner cavity, as well as an input end and an output end which are installed in the case and extend into the inner cavity respectively. The inner of the resonant cavity is also equipped with a metamaterial block including at least one metamaterial layer, and at least one of the input end and the output end is coupled with the metamaterial block by a matching layer. With the resonant cavity of the present invention, the resonance frequency can be reduced by setting the metamaterial block with high permittivity; the coupling performance can be improved by coupling the matching layer between the metamaterial block and the input end as well as the output end; thus the performance of a filter is improved by importing a signal from the input end to the inner of the cavity, and then to the output end with high efficiency. A filter with the resonant cavity is also provided by the present invention.

Description

Resonant cavity and filter having the same

The present application claims priority to Chinese Patent Application No. 2011-1029804, filed on Sep. 30, 2011, the entire disclosure of which is 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

Filters are one of the common devices in radio technology and are widely used in electronic devices such as communication, radar, navigation, electronic countermeasures, satellites, and test instruments. The filter is internally filled with a resonant cavity. The volume of the filter depends mainly on the number and volume of the resonant cavity. The resonant frequency of the microwave cavity depends on the volume of the cavity. Generally, the larger the cavity volume is, the lower the resonance frequency is. The cavity volume is reduced. The higher the resonance frequency is, so how to achieve the situation without increasing the cavity size. Lowering the resonant frequency of the resonant cavity is important for the miniaturization of the filter.

By providing a metamaterial in the cavity, the high refractive index and high dielectric constant of the metamaterial can effectively reduce the resonant frequency of the resonant cavity without changing the volume of the resonant cavity, that is, equivalent to the same resonant frequency. The volume of the resonant cavity is reduced. However, experiments have shown that the coupling effect between the metamaterial and the input and output ends of the resonant cavity is very poor, resulting in low signal introduction and derivation efficiency, which greatly affects the application effect of the metamaterial in the resonant cavity. Summary of the invention

The technical problem to be solved by the present invention is to provide a resonant cavity and a filter with good coupling effect and high signal transmission efficiency in view of the defects in the prior art that the coupling effect of the metamaterial and the resonant cavity is poor.

The present invention provides a resonant cavity including a housing having an inner cavity, an input end and an output end mounted on the housing, the input end and the output end respectively extending into the inner cavity, the resonant cavity Also disposed within the meta-material block, the meta-material block includes at least one meta-material sheet, and at least one of the input end and the output end is coupled to the meta-material block by a matching layer.

The matching layer is configured to receive and radiate signals. The matching layer includes a dielectric plate, a metal patch attached to one side of the dielectric plate, and a metal grounding plate attached to the other surface of the dielectric plate.

Wherein, the metal patch faces the meta-material block, and the metal ground plate faces the housing inner cavity space.

Wherein, the metal patch is a strip or an area patch.

The material of the dielectric plate and the metal patch of the matching layer is the same as the material of the substrate of the metamaterial sheet and the artificial microstructure.

Wherein, the dielectric plate is made of ceramic, polytetrafluoroethylene, epoxy resin, ferroelectric material, ferrite material, ferromagnetic material or FR-4 material.

Wherein, the metal patch is made of copper.

Wherein, the two ends of the metamaterial block are respectively provided with a matching layer, and the two matching layers are respectively connected with the input end and the output end.

The matching layer is a microstrip antenna or a patch antenna.

Wherein the frequency of the matching layer is equivalent to the resonant frequency of the metamaterial block.

Wherein the frequency of the matching layer is on the order of magnitude or adjacent to the resonant frequency of the metamaterial block.

The input end or the output end and the matching layer are wired or wirelessly connected.

Wherein, the matching layer is formed integrally with the metamaterial block.

Wherein, the matching layer is directly in contact with the surface of the metamaterial block or has a gap.

Wherein, the metamaterial sheet layer comprises a substrate and a plurality of artificial microstructures periodically arranged on the substrate, wherein the artificial microstructures are geometric structures composed of wires of conductive materials. Wherein, the artificial microstructure is a cross shape or a cross shape.

Wherein the artificial microstructure is made of copper.

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: By setting a metamaterial block having a high dielectric constant, the resonance frequency can be lowered; and coupling performance can be improved by coupling a matching layer between the metamaterial block and the input end and the output end. Therefore, the signal is efficiently introduced into the cavity from the input end, and the signal is efficiently transmitted from the output end to improve the performance of 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 structural view of a resonant cavity of a preferred embodiment of the present invention;

Figure 2 is a plan view of the resonant cavity shown in Figure 1;

Figure 3 is a cross-sectional view taken along line A-A of Figure 2;

Figure 4 is an exploded view of the metamaterial block and the first and second matching layers;

Figure 5 is a derivative structure in which the artificial microstructure is a "work" shape;

Fig. 6 is a derivative structure in which the artificial microstructure is a "ten" shape. Specific embodiment

The invention relates to a resonant cavity for a filter, the filter comprising at least the resonant cavity. As shown in FIGS. 1 to 4, the resonant cavity includes a housing 1, an input terminal 3, an output terminal 4, a meta-material block 6, and a matching layer 5.

The housing 1 is typically made of copper and has a square inner cavity. A chamber cover 2 can be placed over the housing 1 to enclose the interior cavity into a separate cavity. The input end 3 and the output end 4 are respectively mounted on the side walls of the casing 1 and extend into the inner cavity from the outside. The innovation of the present invention lies in that the metamaterial block 6 and the matching layer 5 are placed in the inner cavity, and the high dielectric constant characteristic of the metamaterial block 6 is utilized to reduce the resonant frequency of the resonant cavity, and on the other hand, the matching layer is utilized. 5 to improve the coupling effect between the metamaterial block 6 and the input terminal 3, the output terminal 4, and improve signal transmission efficiency.

As shown in FIG. 4, the metamaterial block 6 includes at least one metamaterial sheet layer 7, and when there are a plurality of the super material sheet layers 7, the front and rear surfaces thereof are fixedly joined together by mechanical or physical fusion, etc. They can be connected to each other at a distance from each other. Each of the metamaterial sheets 7 is composed of a substrate 71 and a plurality of artificial microstructures 72 attached to the substrate 71 to be periodically arranged. The substrate 71 is used to provide an attachment substrate for the artificial microstructure 72, typically made of a non-metallic material such as FR-4 material, polytetrafluoroethylene, epoxy, ceramic or Si0 ₂ . The artificial microstructure 72 is a structure having a certain geometric shape composed of a wire made of a conductive material, such as a "work" shape, a "ten" shape, and an open resonance. Ring and so on. The conductive material here is usually copper, silver, indium tin oxide or the like.

In the present invention, the high dielectric constant characteristics of the metamaterial are utilized to reduce the resonant frequency of the resonant cavity. Therefore, the artificial microstructure 72 is designed to achieve a high dielectric constant. First, the size of the artificial microstructure 72 is about one-fifth to one-tenth, preferably one-tenth, of the wavelength of the electromagnetic wave corresponding to the resonance frequency. When the artificial microstructures 72 are arranged in a rectangular array, it can also be understood that the row spacing and the column spacing of the arrays are about one tenth of the wavelength, and the size of the artificial microstructures 72 is such that the artificial microstructures 72 can be accommodated. The line spacing and column spacing are within a rectangular grid of length and width, and the largest outer contour of the artificial microstructure 72 can be approximated to the edge of the rectangular grid, i.e., substantially fills the grid. As for the specific size of the artificial microstructure 72, it can be adjusted in a small range according to the simulation result until the resonance frequency satisfies the requirements of the cavity.

In addition, by placing the metamaterial block 6 in the cavity, the resonance frequency can be lowered, but in order to make the frequency reduction effect more obvious, the geometry of the artificial microstructure 72 can select a structural shape that is obviously responsive to the electric field, such as a "work" shape. The first metal wire is formed in a straight line and the two second metal wires respectively connected to the two ends of the first metal wire and perpendicular to the first metal wire; further derivative, the artificial microstructure 72 may include a connection on the basis of the I-shape Four third metal wires at both ends of each of the second metal wires and perpendicular to the second metal wires may further include eight fourth wires respectively connected to the ends of each of the third metal wires and perpendicular to the third metal wires Metal wire, as shown in Figure 5. By analogy, there can also be infinite derivation structures.

Similarly, the artificial microstructure 72 of the metamaterial block 6 of the present invention may also be a derivative of a "ten" shape, as shown in FIG. 4, including two first metal wires which are perpendicular to each other to form a "ten" word and are respectively connected to each Further, the artificial microstructures 72 may also be connected to each of the above-mentioned "ten"-shaped derivatives on the basis of the above-mentioned "ten"-shaped derivative, further extending from the ends of the first metal wires and perpendicular to the first metal wires of the connected first metal wires; Eight third metal lines at both ends of the second metal line and perpendicular to the connected second metal line, and may further include sixteen roots respectively connected to both ends of each third metal line and perpendicular to the third metal line Four metal wires, as shown in Figure 6. Further, by analogy, an infinite derivative structure can be obtained.

Of course, other shapes of the artificial microstructure 72 also cause the super-material sheet 7 to have a high refractive index effect, thereby achieving the frequency reduction purpose of the resonant cavity. Therefore, the artificial microstructure 72 of the present invention is not limited to the above structural form.

Since the metamaterial block 6 and the input end 3 and the output end 4 are completely different materials and properties, if the two sides of the metamaterial block 6 are directly coupled to the input end 3 and the output end 4, the coupling performance and effect are relatively poor. In order to improve the coupling performance, the present invention is provided with a matching layer between the metamaterial block 6 and the input end 3 or the output end 4, and the matching layer 5 may be installed only at the 6-end of the meta-material block, or may be in the super-material block 6 Side average The matching layer 5 is installed. In this embodiment, in order to improve performance, the matching layer 5 is installed on both sides, as shown in FIG. 3 and FIG.

The matching layer 5 of the present invention may be a variety of matching layers capable of receiving and radiating signals, preferably microstrip antennas or patch antennas. As shown in Figs. 2 and 4, the antenna of the present invention comprises a dielectric plate 51, a metal patch 52 attached to the surface of the dielectric plate 51, and a metal ground plate 53 attached to the other surface of the dielectric plate 51. The metal patch 52 of the embodiment is strip-shaped. Of course, it can also be a commonly used area patch having a certain square or other shape, or both an area patch and one or more rafts surrounding the area patch. Striped patch. These patches are formed onto the dielectric plate 51 by an etching process. The input terminal 3 and the output terminal 4 are respectively coupled to the grounding plate of a matching layer 5, and the coupling between them can be either a wired connection or a wireless connection.

In order to improve the coupling performance, the metal patch 52 faces the metamaterial block 6 to be directly coupled with the metamaterial block 6, and the metal ground plate 53 faces the inner cavity space of the casing 1, that is, the metal patch 52 is inwardly and metal-connected. The floor 53 is outward. The dielectric plate 51 may be made of the same material as the substrate 71 of the metamaterial sheet 7, for example, FR-4 material or polytetrafluoroethylene. Similarly, the metal patch 52 and the artificial microstructure 72 can be made of the same conductive material, for example, copper. At the same time, the frequency of the matching layer 5 is preferably equivalent to the resonant frequency of the metamaterial block 6, for example, the frequencies are all on the order of magnitude or adjacent orders of magnitude. Further, the size of the matching layer 5, such as the area and thickness, can be designed to be the same as that of the metamaterial sheet 7, so as to be integrated with the metamaterial block 6, to facilitate mounting and positioning. The sheet-like matching layer 5 may be directly in contact with the surface of the super-material block 6, or may be in contact with but not very close. Of course, the matching layer 5 of the present invention can use not only a microstrip antenna but also other radio frequency antennas.

By using the resonant cavity of the present invention, the resonant frequency can be reduced by providing the metamaterial block 6 having a high dielectric constant; by coupling the matching layer 5 between the metamaterial block 6 and the input terminal 3 and the output terminal 4, the coupling performance can be improved. Therefore, the signal is efficiently introduced into the cavity from the input end, and the signal is efficiently transmitted from the output end to improve the performance of the filter.

The embodiments of the present invention have been described above with reference to the drawings, but the present invention is not limited to the specific embodiments described above, and the specific embodiments described above are merely illustrative and not restrictive, and those skilled in the art In the light of the present invention, many forms may be made without departing from the spirit and scope of the invention as claimed.

Claims

Rights request

A resonant cavity comprising a housing having an internal cavity, an input end and an output end mounted on the housing, the input end and the output end respectively extending into the inner cavity, wherein A super-material block is further disposed within the resonant cavity, the meta-material block includes at least one meta-material sheet, and at least one of the input end and the output end is coupled to the meta-material block by a matching layer.

2. The resonant cavity of claim 1 wherein the matching layer is for receiving and radiating signals.

3. The resonant cavity according to claim 1, wherein the matching layer comprises a dielectric plate, a metal patch attached to one side of the dielectric plate, and a metal connection attached to the other surface of the dielectric plate. floor.

4. The resonant cavity of claim 3, wherein the metal patch faces the super-material block, the metal ground plate facing the housing cavity space.

The resonant cavity according to claim 3, wherein the metal patch is a strip or area patch.

The resonant cavity according to claim 3, wherein the material of the dielectric plate and the metal patch of the matching layer is the same as the material of the substrate of the metamaterial sheet and the artificial microstructure.

7. The resonant cavity according to claim 3, wherein the dielectric plate is made of ceramic, polytetrafluoroethylene, epoxy resin, ferroelectric material, ferrite material, ferromagnetic material or FR-4 material. .

8. The resonant cavity of claim 3, wherein the metal patch is made of copper.

9. The resonant cavity according to claim 1, wherein each of the metamaterial blocks is respectively provided with a matching layer, and the two matching layers are respectively connected with the input end and the output end.

10. The resonant cavity of claim 1 wherein the matching layer is a microstrip antenna or a patch antenna.

11. The resonant cavity of claim 1 wherein the frequency of the matching layer is comparable to the resonant frequency of the metamaterial block.

12. The resonant cavity of claim 11 wherein the frequency of the matching layer is on the order of magnitude or adjacent to the resonant frequency of the metamaterial block.

13. The resonant cavity of claim 1, wherein the input or output is wired or wirelessly connected to the matching layer.

14. The resonant cavity of claim 1 wherein said matching layer is formed integrally with said metamaterial block.

15. The resonant cavity of claim 1 wherein the matching layer is in direct contact with the surface of the metamaterial block or has a gap.

The resonant cavity according to any one of claims 1 to 15, wherein the metamaterial sheet layer comprises a substrate and a plurality of artificial microstructures periodically arranged on the substrate, the artificial The microstructure is a geometrically structured structure composed of wires of a conductive material.

17. The resonant cavity of claim 16, wherein the artificial microstructure is an I-shaped or I-shaped derivative.

18. The resonant cavity of claim 16, wherein the artificial microstructure is a cruciform or cruciform derivative.

19. The resonant cavity of claim 18, wherein the artificial microstructure is made of copper.

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