CN102810752B - Metamaterial and metamaterial antenna - Google Patents

Abstract

The invention relates to a metamaterial and a metamaterial antenna. The metamaterial is arranged in the transmission direction of the radiation source correspondingly; a line formed by connecting the radiation source and a point on first surface of the metamaterial forms an included angle theta with a straight line perpendicular to the metamaterial, the included angle theta uniquely corresponds to a curved surface in the metamaterial and every point in the curved surface uniquely corresponding to the included angle theta has same refractive index, the generatrix of the curved surface is a parabola; the refractive index of the metamaterial reduces gradually with the increase of the included angle theta; and the electromagnetic waves are shot out parallelly from top surface of every torus after going through the metamaterial. The curve jumping of the refractive index of the metamaterial is designed, so that refraction, diffraction and reflection effects at the jumping position are greatly reduced; mutual interference is reduced; and the metamaterial and the metamaterial antenna have high performance.

Description

A kind of Meta Materials and Super-material antenna

Technical field

The present invention relates to electromagnetic arts, more particularly, relate to a kind of Meta Materials and Super-material antenna.

Background technology

In the optics of routine, spherical wave that the point-source of light in lens focus gives off becomes plane wave after lens reflection to utilize lens can make to be positioned at.The convergence of current lens relies on the refraction of the spherical shape of lens to realize, and as shown in Figure 1, the spherical wave that radiator 30 sends penetrates with plane wave after spherical lens 40 converge.Inventor, in enforcement process of the present invention, finds that lens antenna at least exists following technical problem: the volume of sphere lens 40 is large and heavy, is unfavorable for miniaturized use; Sphere lens 40 has very large dependence for shape, needs the direction propagation that more precisely could realize antenna; Reflection of electromagnetic wave interference and loss ratio are comparatively serious, and electromagnetic energy reduces.And the saltus step of the refractive index of most lens antenna is simple and perpendicular to the straight line of lens surface along one, causes electromagnetic wave comparatively large through the refraction of lens, diffraction and reflection, have a strong impact on lens performance.

Summary of the invention

The technical problem to be solved in the present invention is, the defect comparatively large for the above-mentioned refraction of prior art, diffraction and reflection, lens performance is poor, provides a kind of high performance Meta Materials and Super-material antenna.

The technical solution adopted for the present invention to solve the technical problems is: construct a kind of Meta Materials, is relatively arranged on the Electromagnetic Wave Propagation direction of radiation source; If on radiation source and described Meta Materials first surface any line and perpendicular to Meta Materials straight line between angle be θ, a curved surface in the unique corresponding described Meta Materials of angle theta, and the refractive index of everywhere is all identical on the unique corresponding curved surface of angle theta, the bus of described curved surface is parabolic arc; The refractive index of described Meta Materials reduces gradually along with the increase of angle theta; Electromagnetic wave penetrates at each toric top surface being parallel after described Meta Materials.

In Meta Materials of the present invention, the refraction index profile of described curved surface meets:

$n\left(\mathrm{\θ}\right)=\frac{1}{S\left(\mathrm{\θ}\right)}[F(1-\frac{1}{\cos \mathrm{\θ}})+n_{\max }d];$

Wherein S (θ) arc length that is described parabolic arc, F is the distance of described radiation source to described Meta Materials, and d is the thickness of described Meta Materials; n _maxfor the largest refractive index of described Meta Materials.

In Meta Materials of the present invention, the arc length S (θ) of described parabolic arc meets:

$S\left(\mathrm{\θ}\right)=\frac{d}{2}[\frac{\log \left(\right|\tan \mathrm{\θ}|+\sqrt{1+{\tan }^2\mathrm{\θ}})+\mathrm{\δ}}{\left|\tan \mathrm{\θ}\right|+\mathrm{\δ}}+\sqrt{1+{\tan }^2\mathrm{\θ}}];$

Wherein, δ is for presetting decimal.

In Meta Materials of the present invention, with through the center of described Meta Materials first surface and perpendicular to the straight line of described Meta Materials for axis of abscissas, to be parallel to the straight line of described first surface for axis of ordinates through the center of described Meta Materials first surface, the parabolic equation at described parabolic arc place is:

$y\left(x\right)=\tan \mathrm{\θ}(-\frac{1}{2d}{x}^2+x+F).$

In Meta Materials of the present invention, in angle theta and parabolic arc, every bit (x, y) meets following relational expression:

$\mathrm{\θ}(x,y)={\tan }^{-1}\left[\frac{2\mathrm{dy}}{2d(F+x)-x^2}\right].$

The present invention also provides a kind of Super-material antenna, comprises Meta Materials and is arranged on the radiation source in described Meta Materials focus; If on radiation source and described Meta Materials first surface any line and perpendicular to Meta Materials straight line between angle be θ, a curved surface in the unique corresponding described Meta Materials of angle theta, and the refractive index of everywhere is all identical on the unique corresponding curved surface of angle theta, the bus of described curved surface is parabolic arc; The refractive index of described Meta Materials reduces gradually along with the increase of angle theta; Electromagnetic wave penetrates at each toric top surface being parallel after described Meta Materials.

In Super-material antenna of the present invention, the refraction index profile of described curved surface meets:

$n\left(\mathrm{\θ}\right)=\frac{1}{S\left(\mathrm{\θ}\right)}[F(1-\frac{1}{\cos \mathrm{\θ}})+n_{\max }d];$

Wherein S (θ) arc length that is described parabolic arc, F is the distance of described radiation source to described Meta Materials, and d is the thickness of described Meta Materials; n _maxfor the largest refractive index of described Meta Materials.

In Super-material antenna of the present invention, the arc length S (θ) of described parabolic arc meets:

$S\left(\mathrm{\θ}\right)=\frac{d}{2}[\frac{\log \left(\right|\tan \mathrm{\θ}|+\sqrt{1+{\tan }^2\mathrm{\θ}})+\mathrm{\δ}}{\left|\tan \mathrm{\θ}\right|+\mathrm{\δ}}+\sqrt{1+{\tan }^2\mathrm{\θ}}];$ Wherein, δ is for presetting decimal.

In Super-material antenna of the present invention, with through the center of described Meta Materials first surface and perpendicular to the straight line of described Meta Materials for axis of abscissas, to be parallel to the straight line of described first surface for axis of ordinates through the center of described Meta Materials first surface, the parabolic equation at described parabolic arc place is:

$y\left(x\right)=\tan \mathrm{\θ}(-\frac{1}{2d}{x}^2+x+F).$

In Super-material antenna of the present invention, in angle theta and parabolic arc, every bit (x, y) meets following relational expression:

$\mathrm{\θ}(x,y)={\tan }^{-1}\left[\frac{2\mathrm{dy}}{2d(F+x)-x^2}\right].$

Implement technical scheme of the present invention, there is following beneficial effect: the saltus step of the refractive index of Meta Materials is designed to the curved that bus is parabolic arc, thus greatly reduce the refraction of saltus step place, diffraction and reflection effect, alleviate the problem interfering with each other and bring, make Meta Materials and Super-material antenna have more excellent performance.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the invention will be further described, in accompanying drawing:

Fig. 1 is that the lens of existing spherical shape converge electromagnetic schematic diagram;

Fig. 2 is that the Meta Materials of foundation one embodiment of the invention converges electromagnetic schematic diagram;

Fig. 3 is the schematic shapes of the unique corresponding curved surface of an angle theta in the Meta Materials 10 shown in Fig. 2;

Fig. 4 show in Fig. 3 the end view of Meta Materials 10;

Fig. 5 is the parabolic arc schematic diagram shown in Fig. 4;

Fig. 6 is the schematic diagram of variations in refractive index;

Fig. 7 is the coordinate schematic diagram of parabolic arc;

Fig. 8 is the refractive index profile in yx plane.

Embodiment

Fig. 2 is that the Meta Materials of foundation one embodiment of the invention converges electromagnetic schematic diagram, and Meta Materials 10 is relatively arranged on the Electromagnetic Wave Propagation direction of radiation source.

As common practise, we are known, electromagnetic refractive index with proportional, when a branch of electromagnetic wave by a kind of Medium Propagation to another medium time, electromagnetic wave can reflect, when the refraction index profile of material inside is non-homogeneous, electromagnetic wave will to the larger position deviation of refractive index ratio, by the electromagnetic parameter of every bit in design Meta Materials, just can adjust the refraction index profile of Meta Materials, and then reach the object changing electromagnetic wave propagation path.The electromagnetic wave that the spherical wave form sent from radiation source 20 can be dispersed by designing the refraction index profile of Meta Materials 10 according to above-mentioned principle is transformed into the electromagnetic wave of the plane wave form being suitable for long-distance transmissions.

Fig. 3 is the schematic shapes of the unique corresponding curved surface of an angle theta in the Meta Materials 10 shown in Fig. 2.As shown in the figure, if on radiation source 20 and Meta Materials 10 first surface A any line and through Meta Materials 10 first surface A center O and perpendicular to Meta Materials 10 straight line L between angle be θ, a curved surface Cm in the unique corresponding Meta Materials 10 of angle theta, and the refractive index of everywhere is all identical on the unique corresponding curved surface Cm of angle theta, the bus of curved surface Cm is parabolic arc; The refractive index of Meta Materials 10 reduces gradually along with the increase of angle theta; Electromagnetic wave penetrates at each toric top surface being parallel after described Meta Materials.

As shown in Figure 3, the bus of curved surface Cm is parabolic arc m, and curved surface Cm to be rotated around L by parabolic arc m straight line and forms.Fig. 4 shows the end view of Meta Materials 10.The thickness of Meta Materials 10 is as shown in figure d, and L represents the straight line perpendicular to Meta Materials.The side cross-sectional, view of the curved surface that refractive index is identical is two sections of parabolic arc, symmetrical relative to L.Parabolic arc shown in dotted line is the bus of a virtual curved face in Meta Materials 10.In order to the refractive index more clearly described on identical curved surface is identical, the virtual curved face (reality does not exist, and is for convenience, the curved surface fictionalized) of Meta Materials inside is also set forth.As shown in Figure 5, on radiation source and Meta Materials first surface 1 O1 line and through first surface center O and perpendicular to Meta Materials 10 straight line L between angle be θ ₁, corresponding parabolic arc is m1, and on the virtual curved face that this parabolic arc m1 rotates, the refractive index of everywhere is all identical.In like manner, the angle on radiation source and Meta Materials first surface between the line of 1 O2 and straight line L is θ ₂, corresponding parabolic arc is m2, and on the virtual curved face that this parabolic arc m2 rotates, the refractive index of everywhere is all identical.

The refraction index profile of virtual curved face meets: as shown in Figure 6, the wherein arc length of S (θ) bus (parabolic arc m) that is virtual curved face, F is the distance of radiation source 20 to Meta Materials 10, and d is the thickness of Meta Materials 10; n _maxfor the largest refractive index of Meta Materials.

The arc length S (θ) of parabolic arc m meets:

$S\left(\mathrm{\θ}\right)={\∫}_0^d\mathrm{ds}={\∫}_0^d\sqrt{1+{\tan }^2\mathrm{\θ}\frac{x^2}{d^2}}\mathrm{dx}=\frac{d}{2}[\frac{\log \left(\right|\tan \mathrm{\θ}|+\sqrt{1+{\tan }^2\mathrm{\θ}})+\mathrm{\δ}}{\left|\tan \mathrm{\θ}\right|+\mathrm{\δ}}+\sqrt{1+{\tan }^2\mathrm{\θ}}]$

；

Wherein, δ is for presetting decimal, and such as 0.0001, δ can ensure the ratio when angle theta is close to 0 convergence.Angle theta span is

As shown in Figure 7, with through Meta Materials 10 first surface center O and perpendicular to the straight line L of Meta Materials 10 for axis of abscissas, with through Meta Materials 10 first surface center O and be parallel to the straight line of first surface for axis of ordinates, on radiation source and A face, the line of certain 1 O ' and the angle of x-axis are θ, on angle theta and parabolic arc m, every bit (x, y) meets following relational expression:

$\mathrm{\θ}(x,y)={\tan }^{-1}\left[\frac{2\mathrm{dy}}{2d(F+x)-x^2}\right].$

Suppose that the parabolical equation in parabolic arc m place is y (x)=ax ²+ bx+c.This parabola through point (0, F tan θ), i.e. y (0)=c=Ftan θ.In order to make the parallel injection of electromagnetic wave after Meta Materials, then need to make electromagnetic wave parallel with x-axis through the tangent line of Meta Materials second surface B parabolic arc, namely ensure y ' (d)=0.Due to y ' (x)=2ax+b, therefore y ' (d)=2ad+b=0.When also will ensure that electromagnetic wave arrives Meta Materials first surface A in addition, electromagnetic wave is propagated along the tangential direction that angle theta is corresponding, therefore y ' (0)=tan θ.Can obtain parabolical equation by above several condition is the relational expression of every bit (x, y) on angle theta and parabolic arc m can be obtained thus

A curved surface in the unique corresponding Meta Materials of angle theta, this curved surface is rotated around L (x-axis) by bus m, and on unique this corresponding curved surface of angle theta, the refractive index of everywhere is all identical.

Meta Materials can be used for the electromagnetic wave of radiation emission to be converted to plane wave.Its refractive index is along with the increase of angle theta is from n _maxbe reduced to n _min, as shown in Figure 7.Camber line shown in dotted line is the bus of a virtual curved face in torus, and the refractive index on identical curved surface is identical.Be understandable that, Meta Materials provided by the invention also can be applicable to the situation that plane wave converges to focus, is also the reversible sight in Fig. 2.Radiation source, without the need to changing, only need be placed on second surface B side by the structure of Meta Materials itself, and principle is now the same, but the radiation source in the definition of θ should be just the virtual radiation source position being in first surface A side and being positioned at Meta Materials focus.As long as the various application scenarioss applied principle of the present invention and carry out all belong to protection scope of the present invention.

Meta Materials, when the structural design of reality, can be designed as multiple metamaterial sheet, and each lamella comprises the substrate of sheet and multiple man-made microstructure of adhering on the substrate or artificial foramen structure.Refraction index profile demand fulfillment overall after multiple metamaterial sheet combines or approximately meet above-mentioned formula, make the refraction index profile on same curved surface identical, the busbar of curved surface is parabolic arc.Certainly, when actual design, it is more difficult to be designed to accurate parabolic arc, and can be designed to the parabolic arc that is similar to or stepped as required, concrete levels of precision can be selected according to needs.Along with the continuous progress of technology, the mode of design also can be constantly updated, and may have better Meta Materials design technology to realize refractive index provided by the invention arrangement.

For man-made microstructure, each described man-made microstructure is the plane with geometrical pattern or stereochemical structure that are made up of wire, such as but not limited to " ten " font, plane flakes, stereo snow flake shape.Wire can be copper wire or filamentary silver, and the method for carving by etching, electroplating, bore quarter, photoetching, electronics quarter or ion is attached on substrate.In Meta Materials, multiple man-made microstructure makes the refractive index of Meta Materials reduce along with the increase of angle theta.When incident electromagnetic wave is determined, by the topological pattern of appropriate design man-made microstructure and the arrangement of man-made microstructure in electromagnetic wave converging element of different size, just can adjust the refraction index profile of Meta Materials, and then realize the electromagnetic wave that electromagnetic wave that spherical wave form disperses changes plane form into.

In order to represent metamaterial sheet refractive index refractive index regularity of distribution on xy face more intuitively, unit identical for refractive index is connected into a line, and the size of refractive index is represented with the density of line, the closeer refractive index of line is larger, then meet the refraction index profile of the Meta Materials of above all relational expressions as shown in Figure 8.

The present invention also provides a kind of Super-material antenna, and as shown in Figures 2 and 3, the radiation source 20 that Super-material antenna comprises Meta Materials 10 and is arranged in Meta Materials 10 focus, the concrete structure of Meta Materials 10 and variations in refractive index as described above, repeat no more herein.

Previously described Meta Materials can be the shape shown in Fig. 3, and can certainly be made into is that other desired shape is such as circular etc., as long as can meet previously described variations in refractive index rule.

When practical application, in order to make the performance of Meta Materials better, reducing reflection, all impedance matching layer can be set Meta Materials both sides again.Content about impedance matching layer see prior art data, can repeat no more herein.

The present invention is designed to curved in the saltus step of the refractive index of Meta Materials, thus greatly reduces the refraction of saltus step place, diffraction and reflection effect, alleviates the problem interfering with each other and bring, makes Meta Materials have more excellent performance.

By reference to the accompanying drawings embodiments of the invention are described above; but the present invention is not limited to above-mentioned embodiment; above-mentioned embodiment is only schematic; instead of it is restrictive; those of ordinary skill in the art is under enlightenment of the present invention; do not departing under the ambit that present inventive concept and claim protect, also can make a lot of form, these all belong within protection of the present invention.

Claims (10)

1. a Meta Materials, it is characterized in that, be relatively arranged on the Electromagnetic Wave Propagation direction of radiation source, if on radiation source and described Meta Materials first surface any line and perpendicular to Meta Materials straight line between angle be θ, a curved surface in the unique corresponding described Meta Materials of angle theta, intersection and the described line of described curved surface and described first surface are crossing, and the refractive index of everywhere is all identical on the unique corresponding curved surface of angle theta, the bus of described curved surface is parabolic arc, described curved surface is that described parabolic arc forms around the described rotation of the straight line perpendicular to described Meta Materials, the refractive index of described Meta Materials reduces gradually along with the increase of angle theta, electromagnetic wave after described Meta Materials in the parallel injection of the second surface of described Meta Materials.

2. Meta Materials according to claim 1, is characterized in that, the refraction index profile of described curved surface meets:

$n\left(\mathrm{\θ}\right)=\frac{1}{S\left(\mathrm{\θ}\right)}[F(1-\frac{1}{\cos \mathrm{\θ}})+n_{\max }d];$

Wherein S (θ) arc length that is described parabolic arc, F is the distance of described radiation source to described Meta Materials, and d is the thickness of described Meta Materials; n _maxfor the largest refractive index of described Meta Materials.

3. Meta Materials according to claim 2, is characterized in that, the arc length S (θ) of described parabolic arc meets:

$S\left(\mathrm{\θ}\right)=\frac{d}{2}[\frac{\log \left(\right|\tan \mathrm{\θ}|+\sqrt{1+{\tan }^2\mathrm{\θ}})+\mathrm{\δ}}{\left|\tan \mathrm{\θ}\right|+\mathrm{\δ}}+\sqrt{1+{\tan }^2\mathrm{\θ}}];$

Wherein, δ is for presetting decimal.

4. the Meta Materials according to any one of claim 2 ~ 3, it is characterized in that, with through the center of described Meta Materials first surface and perpendicular to the straight line of described Meta Materials for axis of abscissas, to be parallel to the straight line of described first surface for axis of ordinates through the center of described Meta Materials first surface, the parabolic equation at described parabolic arc place is:

$y\left(x\right)=\tan \mathrm{\θ}(-\frac{1}{2d}{x}^2+x+F).$

5. Meta Materials according to claim 4, is characterized in that, in angle theta and parabolic arc, every bit (x, y) meets following relational expression:

$\mathrm{\θ}(x,y)={\tan }^{-1}\left[\frac{2\mathrm{dy}}{2d(F+x)-x^2}\right].$

6. a Super-material antenna, is characterized in that, comprises Meta Materials and is arranged on the radiation source in described Meta Materials focus; If the line of any and the angle perpendicular to Meta Materials and between the straight line of described radiation source are θ on radiation source and described Meta Materials first surface, a curved surface in the unique corresponding described Meta Materials of angle theta, intersection and the described line of described curved surface and described first surface are crossing, and the refractive index of everywhere is all identical on the unique corresponding curved surface of angle theta, the bus of described curved surface is parabolic arc, and described curved surface is that described parabolic arc forms perpendicular to Meta Materials and through the straight line rotation of described radiation source around described; The refractive index of described Meta Materials reduces gradually along with the increase of angle theta; Electromagnetic wave after described Meta Materials in the parallel injection of the second surface of described Meta Materials.

7. Super-material antenna according to claim 6, is characterized in that, the refraction index profile of described curved surface meets:

$n\left(\mathrm{\θ}\right)=\frac{1}{S\left(\mathrm{\θ}\right)}[F(1-\frac{1}{\cos \mathrm{\θ}})+n_{\max }d];$

Wherein S (θ) arc length that is described parabolic arc, F is the distance of described radiation source to described Meta Materials, and d is the thickness of described Meta Materials; n _maxfor the largest refractive index of described Meta Materials.

8. Super-material antenna according to claim 7, is characterized in that, the arc length S (θ) of described parabolic arc meets:

$S\left(\mathrm{\θ}\right)=\frac{d}{2}[\frac{\log \left(\right|\tan \mathrm{\θ}|+\sqrt{1+{\tan }^2\mathrm{\θ}})+\mathrm{\δ}}{\left|\tan \mathrm{\θ}\right|+\mathrm{\δ}}+\sqrt{1+{\tan }^2\mathrm{\θ}}];$ Wherein, δ is for presetting decimal.

9. the Super-material antenna according to any one of claim 7 ~ 8, it is characterized in that, with through the center of described Meta Materials first surface and perpendicular to the straight line of described Meta Materials for axis of abscissas, to be parallel to the straight line of described first surface for axis of ordinates through the center of described Meta Materials first surface

The parabolic equation at described parabolic arc place is:

$y\left(x\right)=\tan \mathrm{\θ}(-\frac{1}{2d}{x}^2+x+F).$

10. Super-material antenna according to claim 9, is characterized in that, in angle theta and parabolic arc, every bit (x, y) meets following relational expression:

$\mathrm{\θ}(x,y)={\tan }^{-1}\left[\frac{2\mathrm{dy}}{2d(F+x)-x^2}\right].$