CN102810752A - 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 ultra material and ultra material antenna

Technical field

The present invention relates to the electromagnetism field, more particularly, relate to a kind of ultra material and ultra material antenna.

Background technology

In the optics of routine, become plane wave after utilizing lens to make to be positioned at spherical wave that the point-source of light on the lens focus gives off through the lens refraction.Converging of lens is to rely on the refraction of the spherical shape of lens to realize at present, and as shown in Figure 1, the spherical wave that radiator 30 sends converges the back through spherical lens 40 and penetrates with plane wave.The inventor is in the embodiment of the present invention process, and find that there is following technical problem at least in lens antenna: the volume of sphere lens 40 is big and heavy, is unfavorable for the use of miniaturization; Sphere lens 40 has very big dependence for shape, needs relatively precisely could realize the direction propagation of antenna; Reflection of electromagnetic wave interference and loss ratio are more serious, and electromagnetic energy reduces.And the saltus step of the refractive index of most lens antennas is simple and perpendicular to the straight line of lens surface, refraction, diffraction and reflection when causing electromagnetic wave through lens are bigger, have a strong impact on lens performance along one.

Summary of the invention

The technical problem that the present invention will solve is, the defective of, lens performance difference big to above-mentioned refraction, diffraction and the reflection of prior art provides a kind of high performance ultra material and ultra material antenna.

The technical solution adopted for the present invention to solve the technical problems is: construct a kind of ultra material, be relatively arranged on the electromagnetic wave propagation direction of radiation source; If the line of any and be θ on radiation source and the said ultra material first surface perpendicular to the angle between the straight line of ultra material; Curved surface in the said ultra material of the unique correspondence of angle theta; And the refractive index of everywhere is all identical on the curved surface of the unique correspondence of angle theta, and the bus of said curved surface is a parabolic arc; The refractive index of said ultra material is along with the increase of angle theta reduces gradually; Electromagnetic wave through behind the said ultra material in the parallel ejaculation of each toric end face.

In ultra material of the present invention, the refraction index profile of said curved surface satisfies:

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

Wherein S (θ) is the arc length of said parabolic arc, and F is the distance of said radiation source to said ultra material, and d is the thickness of said ultra material; n _MaxLargest refractive index for said ultra material.

In ultra material of the present invention, the arc length S of said parabolic arc (θ) satisfies:

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

Wherein, δ is preset decimal.

In ultra material of the present invention; Being axis of abscissas through the center of said ultra material first surface and perpendicular to the straight line of said ultra material; With the center of passing through said ultra material first surface and the straight line that is parallel to said first surface is axis of ordinates, and the parabolic equation at said parabolic arc place is:

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

In ultra material of the present invention, every bit on angle theta and the parabolic arc (x, y) satisfy 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 ultra material antenna, comprises ultra material and is arranged on the radiation source on the said ultra material focus; If the line of any and be θ on radiation source and the said ultra material first surface perpendicular to the angle between the straight line of ultra material; Curved surface in the said ultra material of the unique correspondence of angle theta; And the refractive index of everywhere is all identical on the curved surface of the unique correspondence of angle theta, and the bus of said curved surface is a parabolic arc; The refractive index of said ultra material is along with the increase of angle theta reduces gradually; Electromagnetic wave through behind the said ultra material in the parallel ejaculation of each toric end face.

In ultra material antenna of the present invention, the refraction index profile of said curved surface satisfies:

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

Wherein S (θ) is the arc length of said parabolic arc, and F is the distance of said radiation source to said ultra material, and d is the thickness of said ultra material; n _MaxLargest refractive index for said ultra material.

In ultra material antenna of the present invention, the arc length S of said parabolic arc (θ) satisfies:

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

In ultra material antenna of the present invention; Being axis of abscissas through the center of said ultra material first surface and perpendicular to the straight line of said ultra material; With the center of passing through said ultra material first surface and the straight line that is parallel to said first surface is axis of ordinates, and the parabolic equation at said parabolic arc place is:

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

In ultra material antenna of the present invention, every bit on angle theta and the parabolic arc (x, y) satisfy following relational expression:

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

The technical scheme of embodiment of the present invention; Have following beneficial effect: the saltus step that will surpass the refractive index of material is designed to the curved surface shape that bus is a parabolic arc; Thereby significantly reduce refraction, diffraction and the reflection effect of saltus step place; Alleviate the problem of bringing that interferes with each other, made ultra material and ultra material antenna have excellent more performance.

Description of drawings

To combine accompanying drawing and embodiment that the present invention is described further below, in the accompanying drawing:

Fig. 1 is that the lens of existing spherical shape converge electromagnetic sketch map;

Fig. 2 is that the ultra material according to one embodiment of the invention converges electromagnetic sketch map;

Fig. 3 is the shape sketch map of a curved surface of the unique correspondences of an angle theta in the ultra material shown in Figure 2 10;

Fig. 4 show among Fig. 3 the end view of ultra material 10;

Fig. 5 is a parabolic arc sketch map shown in Figure 4;

Fig. 6 is the sketch map of variations in refractive index;

Fig. 7 is the coordinate sketch map of parabolic arc;

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

Embodiment

Fig. 2 is that the ultra material according to one embodiment of the invention converges electromagnetic sketch map, and ultra material 10 is relatively arranged on the electromagnetic wave propagation direction of radiation source.

We can know as common practise; Electromagnetic refractive index is proportional with

; When a branch of electromagnetic wave is propagated into other a kind of medium by a kind of medium; Electromagnetic wave can reflect; When the inner refraction index profile of material was non-homogeneous, electromagnetic wave will be to the bigger position deviation of refractive index ratio, through designing the electromagnetic parameter of every bit in the ultra material; Just can adjust, and then reach the purpose that changes the electromagnetic wave propagation path the refraction index profile of ultra material.The electromagnetic wave that the spherical wave form sent from radiation source 20 is dispersed according to above-mentioned principle is transformed into the electromagnetic wave of the plane wave form that is suitable for long-distance transmissions.

Fig. 3 is the shape sketch map of a curved surface of the unique correspondences of an angle theta in the ultra material shown in Figure 2 10.As shown in the figure; If it is θ with the center O of passing through ultra material 10 first surface A and perpendicular to the angle between the straight line L of ultra material 10 that radiation source 20 and ultra material 10 first surface A go up the line of a bit; Curved surface Cm in the ultra material 10 of the unique correspondence of angle theta; And the refractive index that the curved surface Cm of the unique correspondence of angle theta goes up the everywhere is all identical, and the bus of curved surface Cm is a parabolic arc; The refractive index of ultra material 10 is along with the increase of angle theta reduces gradually; Electromagnetic wave through behind the said ultra material in the parallel ejaculation of each toric end face.

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

The refraction index profile of virtual curved face satisfies:

As shown in Figure 6, wherein S (θ) is the arc length of the bus (parabolic arc m) of virtual curved face, and F is the distance of radiation source 20 to ultra material 10, and d is the thickness of ultra material 10; n _MaxLargest refractive index for ultra material.

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

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

；

Wherein, δ is preset decimal; Such as 0.0001, δ can guarantee ratio when angle theta is near 0

convergence.The angle theta span is

As shown in Figure 7; Being axis of abscissas through the center O of ultra material 10 first surfaces and perpendicular to the straight line L of ultra material 10; With center O of passing through ultra material 10 first surfaces and the straight line that is parallel to first surface is axis of ordinates; The angle of the line of certain 1 O ' and x axle is θ on radiation source and the A face, the last every bit of angle theta and parabolic arc m (x, y) satisfy following relational expression:

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

Suppose that it is y (x)=ax that parabolic arc m belongs to parabolical equation ²+ bx+c.This parabola is through point (0, F tan θ), i.e. y (0)=c=Ftan θ.In order to make through the parallel ejaculation of electromagnetic wave behind the ultra material, the tangent line of parabolic arc is parallel with the x axle in the time of then need making electromagnetic wave pass through ultra material second surface B, guarantees that promptly y ' (d)=0.Since y ' (x)=2ax+b, so y ' (d)=2ad+b=0.In the time of will guaranteeing also that in addition electromagnetic wave arrives ultra material first surface A, electromagnetic wave is along the corresponding tangential direction propagation of angle theta, so y ' (0)=tan θ.Parabolical equation can be obtained by above several conditions and angle theta and parabolic arc m upward every bit (x, relational expression y)

can be got for

thus

Curved surface in the ultra material of the unique correspondence of angle theta, around L (x axle) rotation, the refractive index of everywhere is all identical on this curved surface of the unique correspondence of angle theta by bus m for this curved surface.

Ultra material can be used for converting the electromagnetic wave of radiation source emission into plane wave.Its refractive index along with the increase of angle theta from n _MaxBe reduced to n _Min, as shown in Figure 7.Camber line shown in the dotted line is the bus of a virtual curved face in the torus, and the refractive index on the identical curved surface is identical.It is understandable that ultra material provided by the invention also can be applicable to the situation that plane wave converges to focus, also is the reversible sight among Fig. 2.The structure of ultra material itself need not to change, and only need that radiation source is placed on second surface B one side and get final product, and the principle of this moment is the same, but the radiation source in the definition of θ just should be the virtual radiation source position that is in first surface A side and is positioned at ultra material focus.The various application scenarioss that carry out so long as use principle of the present invention all belong to protection scope of the present invention.

Ultra material can be designed as a plurality of ultra sheet of material when practical structure designs, each lamella comprises the substrate of sheet and attached to a plurality of artificial micro-structural on the said substrate or artificial pore structure.A plurality of ultra sheet of material combine that the whole refraction index profile in back need satisfy or approximately satisfy above-mentioned formula, make that the refraction index profile on same curved surface is identical, and the busbar of curved surface is a parabolic arc.Certainly, when actual design, possibly be designed to relatively difficulty of accurate parabolic arc, the parabolic arc that can be designed to as required to be similar to or stepped, concrete levels of precision can be selected according to needs.Along with continuous advancement in technology, the mode of design also can be brought in constant renewal in, and possibly have better ultra material design technology and realize that refractive index provided by the invention arranges.

For artificial micro-structural, plane with geometrical pattern or the stereochemical structure of each said artificial micro-structural for being made up of wire is such as but not limited to " ten " font, plane flakes, three-dimensional flakes.Wire can be copper wire or filamentary silver, can be through etching, plating, brill quarter, photoetching, electronics is carved or ion is carved method attached on the substrate.A plurality of artificial micro-structurals make the refractive index of ultra material reduce along with the increase of angle theta in the ultra material.Under the situation that incident electromagnetic wave is confirmed; Artificial micro-structural the arranging in the electromagnetic wave focal element of topological pattern and different size through the artificial micro-structural of appropriate design; Just can adjust the refraction index profile of ultra material, and then realize that electromagnetic wave that the spherical wave form is dispersed changes the electromagnetic wave of plane form into.

In order to represent ultra sheet of material refractive index refractive index regularity of distribution on the xy face more intuitively; The unit that refractive index is identical is linked to be a line; And represent the size of refractive index with the density of line; The close more refractive index of line is big more, and the refraction index profile of ultra material that then meets above all relational expressions is as shown in Figure 8.

The present invention also provides a kind of ultra material antenna, and as shown in Figures 2 and 3, ultra material antenna comprises ultra material 10 and be arranged on the radiation source 20 on ultra material 10 focuses that the concrete structure and the variations in refractive index of ultra material 10 are as indicated above, repeat no more here.

The described ultra material of preamble can be a shape shown in Figure 3, and can certainly be made into is that other shapes that need are for example circular etc., gets final product so long as can satisfy the described variations in refractive index rule of preamble.

When practical application, in order to make the performance of ultra material better, reduce reflection, can impedance matching layer all be set ultra again material both sides.Content about impedance matching layer can repeat no more referring to the prior art data here.

The present invention is designed to the curved surface shape in the saltus step of the refractive index of ultra material, thereby significantly reduces refraction, diffraction and the reflection effect of saltus step place, has alleviated the problem of bringing that interferes with each other, and makes ultra material have excellent more performance.

Combine accompanying drawing that embodiments of the invention are described above; But the present invention is not limited to above-mentioned embodiment, and above-mentioned embodiment only is schematically, rather than restrictive; Those of ordinary skill in the art is under enlightenment of the present invention; Not breaking away under the scope situation that aim of the present invention and claim protect, also can make a lot of forms, these all belong within the protection of the present invention.

Claims (10)

1. ultra material; It is characterized in that; Be relatively arranged on the electromagnetic wave propagation direction of radiation source, establish on radiation source and the said ultra material first surface line of any and be θ, the curved surface in the said ultra material of the unique correspondence of angle theta perpendicular to the angle between the straight line of ultra material; And the refractive index of everywhere is all identical on the curved surface of the unique correspondence of angle theta, and the bus of said curved surface is a parabolic arc; The refractive index of said ultra material is along with the increase of angle theta reduces gradually; Electromagnetic wave through behind the said ultra material in the parallel ejaculation of the second surface of said ultra material.

2. ultra material according to claim 1 is characterized in that, the refraction index profile of said curved surface satisfies:

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

Wherein S (θ) is the arc length of said parabolic arc, and F is the distance of said radiation source to said ultra material, and d is the thickness of said ultra material; n _MaxLargest refractive index for said ultra material.

3. ultra material according to claim 2 is characterized in that, the arc length S of said parabolic arc (θ) satisfies:

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

Wherein, δ is preset decimal.

4. according to each described ultra material of claim 2～3; It is characterized in that; Being axis of abscissas through the center of said ultra material first surface and perpendicular to the straight line of said ultra material; With the center of passing through said ultra material first surface and the straight line that is parallel to said first surface is axis of ordinates, and the parabolic equation at said parabolic arc place is:

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

5. ultra material according to claim 4 is characterized in that, every bit on angle theta and the parabolic arc (x, y) satisfy following relational expression:

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

6. a ultra material antenna is characterized in that, comprises ultra material and is arranged on the radiation source on the said ultra material focus; If the line of any and be θ on radiation source and the said ultra material first surface perpendicular to the angle between the straight line of ultra material; Curved surface in the said ultra material of the unique correspondence of angle theta; And the refractive index of everywhere is all identical on the curved surface of the unique correspondence of angle theta, and the bus of said curved surface is a parabolic arc; The refractive index of said ultra material is along with the increase of angle theta reduces gradually; Electromagnetic wave through behind the said ultra material in the parallel ejaculation of the second surface of said ultra material.

7. ultra material antenna according to claim 6 is characterized in that, the refraction index profile of said curved surface satisfies:

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

Wherein S (θ) is the arc length of said parabolic arc, and F is the distance of said radiation source to said ultra material, and d is the thickness of said ultra material; n _MaxLargest refractive index for said ultra material.

8. ultra material antenna according to claim 7 is characterized in that, the arc length S of said parabolic arc (θ) satisfies:

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

9. according to each described ultra material antenna of claim 7～8; It is characterized in that; Being axis of abscissas through the center of said ultra material first surface and perpendicular to the straight line of said ultra material; With the center of passing through said ultra material first surface and the straight line that is parallel to said first surface is axis of ordinates

The parabolic equation at said parabolic arc place is:

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

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

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

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