WO2013029371A1 - Metamaterial-based microstrip - Google Patents

Abstract

The present invention relates to the field of microstrip. Provided is a metamaterial-based microstrip. The microstrip comprises a metal strip, a dielectric substrate, and a ground plate. The dielectric substrate is a metamaterial substrate. The metamaterial substrate comprises multiple first metamaterial lamellae. The metal strip and the ground plate respectively are arranged on two sides of the metamaterial substrate or on a same side of the metamaterial substrate. By implementing the arrangement of refractive indexes via the metamaterial substrate, the present invention allows for effective inhibition of space wave leakage, thus solving the problem of electromagnetic wave crosstalk between adjacent microstrips, while at the same time, the metamaterial substrate is provided with a simplified manufacturing process, where a complex splicing technique is obviated, thereby allowing for reduced costs.

Description

 Metamaterial based microstrip line

[Technical Field]

 The present invention relates to the field of microstrip lines and, more particularly, to a microstrip line based on metamaterials.

 【Background technique】

Microstrip Line is a hybrid microwave integrated circuit (Hybrid Microwave) Integrated Circuits, HMIC) and monolithic microwave integrated circuits (Monolithic Microwave Integrated One of the most widely used planar transmission lines in Circuits, MMIC. Structurally, the microstrip line is placed on a ground plate by a very thin metal strip at a much smaller distance than the wavelength, and the metal strip is separated from the ground plane by a dielectric substrate.

The outstanding advantage of the microstrip line is that it is compact and lightweight, and can be used to make complex microwave circuits in a small volume by stereolithography, photolithography, etching, etc., and is easy to integrate with other microwave devices to realize microwave components and systems. Integration.

With the increasing miniaturization of microwave components and systems, in some cases where volume and weight are demanding, microstrip transmission lines can be used instead of waveguides to form microwave circuits and form various complex planar circuits on the same substrate, including Bridge circuit, matching load, attenuator antenna, etc. However, the use of microstrip line transmission also has the disadvantages of large loss of microstrip line, crosstalk caused by easy leakage of electromagnetic energy, low Q value, difficulty in fine adjustment, and small power capacity.

In the process of using microstrip line transmission, the guided electromagnetic wave on the microstrip line continuously radiates energy along the axial direction of the microstrip line to generate leakage waves, wherein the electromagnetic wave leakage has two forms: surface wave form 2 and space wave form 1 ,As shown in Figure 1. It is known that there is a leakage main mode in the high frequency band of the microstrip line. This leakage main mode leaks electromagnetic wave energy outward in the form of surface waves. In the low frequency band, each higher order mode of the microstrip line is in the form of spatial wave. External leakage of electromagnetic wave energy. Whether it is surface wave leakage or space wave leakage, these leakage waves are harmful in integrated circuits, which not only bring about a drop in transmission power, but also cause leakage of electromagnetic energy to other surrounding circuits. The overall performance of the system is degraded, so it is necessary to suppress leakage waves.

In the prior art, a method for suppressing leakage of a microstrip main mode is mainly to apply a thin dielectric layer having a sufficiently large dielectric constant on the microstrip line; however, for the suppression of high order mode leakage of the microstrip line, there is no What is a simple and effective method. This is mainly due to the difference in the physical mechanism of the leakage of the main mode of the microstrip line and the leakage of the high-order mode. The spatial wave leakage of the higher-order mode of the microstrip line is hardly completely suppressed.

 [Summary of the Invention]

The object of the present invention is to overcome the defects of the spatial wave leakage of the high-order mode of the microstrip line in the prior art, and provide a microstrip line based on a metamaterial, which can effectively suppress the leakage of the space wave and solve the problem between the microstrip lines. The problem of electromagnetic wave crosstalk.

The invention provides a metamaterial-based microstrip line, which comprises a metal strip, a dielectric substrate and a grounding plate, the dielectric substrate is a metamaterial substrate, and the metamaterial substrate comprises a plurality of first metamaterial sheets, wherein the metal strips are connected The floors are located on either side of the metamaterial substrate or on the same side of the metamaterial substrate.

According to a preferred embodiment of the present invention, the metal strip and the ground plate are respectively located on both sides of the metamaterial substrate and are in close contact with the metamaterial substrate.

According to a preferred embodiment of the invention, the metal strip comprises two identical metal strips.

According to a preferred embodiment of the present invention, the metal strip and the grounding plate are respectively located on both sides of the metamaterial substrate, and the metal strip is closely attached to one side of the metamaterial substrate, and the grounding plate is suspended directly under the other side of the metamaterial substrate.

According to a preferred embodiment of the present invention, the metal strip and the ground plate are located on the same side of the metamaterial substrate, and the metal strip is in close contact with the metamaterial substrate, and the ground plate is suspended directly below the metamaterial substrate.

According to a preferred embodiment of the present invention, the plurality of first metamaterial sheets have the same refractive index distribution, wherein the refractive index distribution of each of the first metamaterial sheets is: the smallest refractive index directly under the metal strip And the refractive index of the two sides away from the metal strip gradually increases.

In accordance with a preferred embodiment of the present invention, the first metamaterial sheet comprises a plurality of metamaterial units comprising an artificial microstructure and a unit substrate for attachment of the artificial microstructure.

According to a preferred embodiment of the invention, the artificial microstructure is a planar structure or a three-dimensional structure comprising at least one wire responsive to an electromagnetic field, the wire being a copper wire or a silver wire.

In accordance with a preferred embodiment of the invention, the wire is attached to the unit substrate by etching, electroplating, drilling, photolithography, electron engraving or ion engraving.

According to a preferred embodiment of the invention, the artificial microstructure is any one of a snowflake-shaped or snowflake-shaped derivative.

According to a preferred embodiment of the present invention, the material of the unit substrate is made of a ceramic material, an epoxy resin, a polytetrafluoroethylene, a ferroelectric material, a ferrite material or a ferromagnetic material.

According to a preferred embodiment of the present invention, the microstrip line further includes a metamaterial film, the metamaterial film and the metal strip are located on one side of the metamaterial substrate, and are in close contact with the metamaterial substrate, wherein the metamaterial film covers the metal strip.

In accordance with a preferred embodiment of the present invention, the metamaterial film comprises a plurality of second metamaterial sheets, and the plurality of second metamaterial sheets have the same refractive index profile.

According to a preferred embodiment of the present invention, the refractive index distribution of the second metamaterial sheet layer is such that the refractive index distribution in the second metamaterial sheet layer is uniform, and the refractive index has a refractive index ranging from 0-1.

According to a preferred embodiment of the invention, the second metamaterial sheet has a refractive index of 0.7.

In accordance with a preferred embodiment of the present invention, the first metamaterial sheet layer and the second metamaterial sheet layer each comprise a plurality of metamaterial units comprising an artificial microstructure and a unit substrate for attachment of the artificial microstructure.

According to a preferred embodiment of the invention, the artificial microstructure is a planar structure or a three-dimensional structure comprising at least one wire responsive to an electromagnetic field, the wire being a copper wire or a silver wire.

In accordance with a preferred embodiment of the invention, the wire is attached to the unit substrate by etching, electroplating, drilling, photolithography, electron engraving or ion engraving.

According to a preferred embodiment of the invention, the artificial microstructure is any one of a snowflake-shaped or snowflake-shaped derivative.

According to a preferred embodiment of the present invention, the material of the unit substrate is made of a ceramic material, an epoxy resin, a polytetrafluoroethylene, a ferroelectric material, a ferrite material or a ferromagnetic material.

Compared with the prior art, the invention has the following beneficial effects:

1. The present invention uses a metamaterial as a dielectric substrate, and by adjusting the refractive index distribution inside the supermaterial substrate, the spatial wave leakage of the microstrip line is effectively suppressed.

2. The present invention realizes the refractive index required in practical applications by changing the change of the dielectric constant inside the metamaterial, and the process is simple and easy to mass-produce.

3, the use of metamaterials as a substrate material, eliminating the need for media splicing technology, saving costs.

4. A super-material based microstrip line according to the present invention comprises a layer of metamaterial film disposed on a dielectric substrate, and the super material film covers the metal strip, thereby effectively suppressing leakage waves in the form of spatial waves of the microstrip line, and reducing Electromagnetic crosstalk of adjacent microstrip lines.

 [Description of the Drawings]

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention. Other drawings may also be obtained from those of ordinary skill in the art in light of the inventive work. among them:

1 is a schematic view showing two forms of leakage waves of a microstrip line in the prior art;

2 is a schematic structural view of a metamaterial-based microstrip line according to a first embodiment of the present invention;

3 is a schematic structural view of the metamaterial substrate of FIG. 2;

Figure 4 is a schematic structural view of the metamaterial unit of Figure 2;

Figure 5 is a schematic view of a second embodiment of the present invention;

Figure 6 is a schematic view showing the structure of the super-material film of Figure 5;

Figure 7 is a schematic view of a third embodiment of the present invention;

Figure 8 is a schematic view of a fourth embodiment of the present invention;

Figure 9 is a schematic view of a fifth embodiment of the present invention.

 【detailed description】

The present invention will be further described in detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

Example 1

As shown in FIG. 2, the present invention discloses a metamaterial-based microstrip line including a metal strip 10, a dielectric substrate 30, and a grounding plate 20, wherein the metal strip 10 and the grounding plate 20 are respectively distributed on the medium. Both sides of the substrate 30, and the metal strip 10 is in close contact with the upper side of the dielectric substrate 30 by means of a printed circuit board.

In a preferred embodiment of the present invention, the grounding plate 20 is in close contact with the lower side of the dielectric substrate 30. In order to suppress the leakage of the spatial wave generated during the electromagnetic wave transmission of the metal strip 10, the metamaterial substrate is used as the dielectric substrate 30, thereby reducing the phase. Electromagnetic crosstalk between adjacent microstrip lines.

Referring to FIGS. 3 and 4, the metamaterial substrate 30 includes a plurality of first metamaterial sheets 301, wherein each first metamaterial sheet 301 includes a plurality of metamaterial units 40, and the metamaterial unit 40 includes artificial The microstructure 402 is coupled to a unit substrate 401 for attachment to the artificial microstructure 402.

In an embodiment of the invention, the plurality of first metamaterial sheets 301 preferably have the same refractive index profile.

The refractive index distribution pattern of each of the first metamaterial sheets 301 is such that, as shown in FIG. 3, the refractive index immediately below the corresponding metal strip 10 is the smallest, and the refractive index gradually increases away from the sides of the metal strip 10.

In order to realize the change of the refractive index shown in FIG. 3 for each of the first metamaterial sheets 301 of the metamaterial substrate 30, theoretically and practically, the topology, geometry and unit cell of the artificial microstructure 402 can be obtained. The distribution on the 401 is designed. The unit substrate 401 is made of a dielectric insulating material, and the manufacturing material thereof includes a ceramic material, a polymer material, a ferroelectric material, a ferrite material or a ferromagnetic material, wherein the polymer material may be a ring. Oxygen resin or polytetrafluoroethylene. The artificial microstructure 402 is a metal wire which is attached to the unit substrate 401 in a certain geometric shape and is responsive to electromagnetic waves. The metal wire may be a copper wire or a silver wire having a cylindrical or flat shape, and is generally made of copper because Copper wire is relatively cheap. Of course, the cross section of the wire can also be other shapes. The metal wires are attached to the unit substrate 401 by etching, electroplating, drilling, photolithography, electron engraving or ion etching, and the first metamaterial sheet layer 301 includes a plurality of metamaterial units 40, each of the metamaterial units 40. Having an artificial microstructure 402, each of the metamaterial units 40 is responsive to electromagnetic waves passing therethrough, thereby affecting the transmission of electromagnetic waves therein, the size of each metamaterial unit 40 being dependent on the electromagnetic waves that need to be responsive, typically the desired response One tenth of the wavelength of the electromagnetic wave, otherwise the arrangement of metamaterial units 40 containing artificial microstructures 402 in space cannot be considered continuous in space.

In the case of the selection of the unit substrate 401, the equivalent dielectric constant and equivalent of each place on the metamaterial can be adjusted by adjusting the shape and size of the artificial microstructure 402 and its spatial distribution on the unit substrate 401. The magnetic permeability in turn changes the equivalent refractive index throughout the metamaterial. When the artificial microstructure 402 adopts the same geometry, the larger the size of the artificial microstructure at a certain place, the larger the equivalent dielectric constant and the larger the refractive index.

The pattern of the artificial microstructure 402 used in this embodiment is a snowflake-shaped derivative pattern. As can be seen from FIG. 3 and FIG. 4, the size of the snow-like artificial microstructure 402 gradually increases from the directly under the metal plate 10 to both sides.

Example 2

As shown in FIGS. 5-6, another embodiment of the present invention differs from Embodiment 1 in that the microstrip line further includes a metamaterial film 50 covering the metal strip 10. Wherein, the metamaterial film 50 includes a plurality of second metamaterial sheets 501, and the plurality of second metamaterial sheets 501 have the same refractive index distribution. The second metamaterial sheet layer 501 includes a plurality of metamaterial units 40. Wherein, the refractive index distribution in the second metamaterial sheet layer 501 is uniform, but the refractive index ranges from 0 to 1, because this refractive index range is the refractive index range of the medium for manufacturing the invisibility cloak, and such super The material film covers the metal strip 10, which can effectively suppress the leakage of the spatial wave form of the microstrip line and reduce the electromagnetic wave crosstalk between adjacent microstrip lines. In a preferred embodiment of the invention, the refractive index in the second metamaterial sheet layer 501 has a value of 0.7.

Example 3

As shown in FIG. 7, this embodiment discloses a super material-based suspended microstrip line, which is different from Embodiment 1 in that the grounding plate 20 is suspended directly below the metamaterial substrate 30 and is not closely attached. On the metamaterial substrate 30.

Example 4

As shown in FIG. 8 , this embodiment discloses an inverted microstrip line based on metamaterial, which is different from Embodiment 3 in that the metal plate 10 is located on the same side as the ground plate 20 and is tightly attached to the metamaterial substrate 30. Stick together.

Example 5

As shown in FIG. 9, it is a metamaterial-based coupled microstrip line, which differs from Embodiment 1 in that two identical metal strips 10 are disposed on one side of the metamaterial substrate 30, and the other side is provided. There is a ground plate 20 in which the refractive index distribution of the metamaterial substrate under each of the metal strips 10 is the same as in the first embodiment.

The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and modifications made without departing from the spirit and scope of the present invention. Simplifications should all be equivalent replacements and are included in the scope of the present invention.

Claims (20)

1. A micromaterial based microstrip line, the microstrip line comprising a metal strip, a dielectric substrate, and a grounding plate, wherein the dielectric substrate is a metamaterial substrate, and the metamaterial substrate comprises a plurality of first metamaterials a layer, wherein the metal strip and the ground plate are respectively located on two sides of the metamaterial substrate or on the same side of the metamaterial substrate.
2. The microstrip line according to claim 1, wherein the metal strip and the grounding plate are respectively located on both sides of the metamaterial substrate and are in close contact with the metamaterial substrate.
3. The metamaterial-based microstrip line according to claim 2, wherein the metal strip comprises two identical metal strips.
4. The microstrip line according to claim 1, wherein the metal strip and the grounding plate are respectively located at two sides of the metamaterial substrate, and the metal strip is closely attached to one side of the metamaterial substrate. The ground plate is suspended directly below the other side of the metamaterial substrate.
5. The microstrip line according to claim 1, wherein the metal strip and the ground plate are located on the same side of the metamaterial substrate, and the metal strip is in close contact with the metamaterial substrate, A ground plate is suspended directly below the metamaterial substrate.
6. The microstrip line according to claim 1, wherein a plurality of said first metamaterial sheets have the same refractive index distribution, wherein a refractive index distribution of each of said first metamaterial sheets is The refractive index at the bottom directly under the metal strip is the smallest, and the refractive index away from both sides of the metal strip is gradually increased.
7. The microstrip line according to claim 6, wherein said first metamaterial sheet layer comprises a plurality of metamaterial units, said metamaterial unit comprising an artificial microstructure and a unit base for attachment of said artificial microstructure material.
8. The microstrip line according to claim 7, wherein the artificial microstructure is a planar structure or a three-dimensional structure comprising at least one wire responsive to an electromagnetic field, the wire being a copper wire or a silver wire.
9. The microstrip line according to claim 8, wherein the wire is attached to the unit substrate by etching, plating, drilling, photolithography, electron engraving or ion etching.
10. The microstrip line according to claim 7, wherein the artificial microstructure is any one of a snowflake-shaped or snowflake-shaped derivative.
11. The microstrip line according to claim 10, wherein the material of the unit substrate is made of a ceramic material, an epoxy resin, a polytetrafluoroethylene, a ferroelectric material, a ferrite material or a ferromagnetic material.
12. The microstrip line according to claim 6, wherein the microstrip line further comprises a metamaterial film, the metamaterial film and the metal strip are located on one side of the metamaterial substrate, and are in close contact with The metamaterial substrate, wherein the metamaterial film covers the metal strip.
13. The microstrip line according to claim 12, wherein the metamaterial film comprises a plurality of second metamaterial sheets, and the plurality of second metamaterial sheets have the same refractive index profile.
14. The microstrip line according to claim 13, wherein the refractive index distribution of the second metamaterial sheet is such that the refractive index distribution in the second metamaterial sheet is uniform and its refraction The range of values is: 0-1.
15. The microstrip line according to claim 14, wherein the second metamaterial sheet has a refractive index of 0.7.
16. The microstrip line according to claim 13, wherein said first metamaterial sheet layer and said second metamaterial sheet layer each comprise a plurality of metamaterial units, said metamaterial unit comprising an artificial microstructure and a supply A unit substrate to which an artificial microstructure is attached.
17. The microstrip line according to claim 16, wherein the artificial microstructure is a planar structure or a three-dimensional structure comprising at least one wire responsive to an electromagnetic field, the wire being a copper wire or a silver wire.
18. The microstrip line according to claim 17, wherein the wire is attached to the unit substrate by etching, plating, drilling, photolithography, electron engraving or ion engraving.
19. The microstrip line according to claim 16, wherein the artificial microstructure is any one of a snowflake-shaped or snowflake-shaped derivative.
20. The microstrip line according to claim 16, wherein the material of the unit substrate is made of a ceramic material, an epoxy resin, a polytetrafluoroethylene, a ferroelectric material, a ferrite material or a ferromagnetic material.

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