CN102904058A - Metamaterial - Google Patents

Abstract

The invention relates to metamaterial. The metamaterial includes a plurality of concentric rings which have lateral curved surfaces and attach to one another tightly. The bottom radius of each ring is smaller than the top radius. An included angle between a straight line perpendicular to the metamaterial and a connecting line of a radiation source and a point at the bottom of the ring i is theta. The included angle theta only corresponds to a curved surface of the ring I, and the positions on the curved surface only corresponding to the included angle theta are equal in refractive index. The refractive index of each ring decreases with increase of the include angle theta. Jumps of the refractive index of the metamaterial are curved, so that refraction, diffraction and reflection effects of the jumps are reduced greatly. The problems caused by mutual interference are solved, and the metamaterial has better properties.

Description

A kind of super material

Technical field

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

Background technology

In the optics of routine, the spherical wave that utilizes lens to make to be positioned at the point-source of light on the lens focus to give off becomes plane wave through behind the lens reflection.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 penetrates with plane wave after converging through spherical lens 40.The inventor is in implementing process of the present invention, and find that there is following technical problem at least in lens antenna: the volume of sphere lens 40 is large and heavy, is unfavorable for the use of miniaturization; Sphere lens 40 has very large 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 is simple and perpendicular to the straight line of lens surface, refraction, diffraction and reflection when causing electromagnetic wave through lens are larger, have a strong impact on lens performance along one.

Summary of the invention

The technical problem to be solved in the present invention is,, lens performance poor defective large for above-mentioned refraction, diffraction and the reflection of prior art provide a kind of high performance super material.

The technical solution adopted for the present invention to solve the technical problems is: construct a kind of super material, it is curved surface and the concentric circles ring body that fits tightly each other that described super material is divided into a plurality of side surfaces; Each toric bottom surface radius is less than the end face radius; Electromagnetic wave through behind the described super material in the parallel ejaculation of each toric end face;

If the line of any and be θ perpendicular to the angle between the straight line of super material on radiation source and i the torus bottom surface, the curved surface in unique corresponding i the torus of angle theta, and the refractive index of everywhere is all identical on the curved surface of the unique correspondence of angle theta; Each toric refractive index is along with the increase of angle theta reduces gradually.

In super material of the present invention, establish on radiation source and i the torus bottom surface excircle line of any and be θ perpendicular to the angle between the straight line of super material _i, i is positive integer and less the closer to i corresponding to the torus of super material center; Wherein, angle theta _iSatisfy following formula:

$\sin c\left({\mathrm{\θ}}_i\right)=\frac{d}{\mathrm{\λ}}(n_{\max (i+1)}-n_{\min \left(i\right)});$

$s\×(\frac{1}{\cos {\mathrm{\θ}}_i}-\frac{1}{\cos {\mathrm{\θ}}_{i-1}})=\frac{d}{\sin c\left({\mathrm{\θ}}_{i-1}\right)}{n}_{\max \left(i\right)}-\frac{d}{\sin c\left({\mathrm{\θ}}_i\right)}{n}_{\min \left(i\right)});$

Wherein, $\sin c\left({\mathrm{\θ}}_i\right)=\frac{\sin \left({\mathrm{\θ}}_i\right)}{{\mathrm{\θ}}_i},$ $\sin c\left({\mathrm{\θ}}_{i-1}\right)=\frac{\sin \left({\mathrm{\θ}}_{i-1}\right)}{{\mathrm{\θ}}_{i-1}},$ θ ₀=0; S is that described radiation source is to the distance of described super material; D is the thickness of described super material; λ is electromagnetic wavelength, n _{Max (i)}, n _{Min (i)}Be respectively i toric largest refractive index and minimum refractive index, n _{Max (i+1)}, n _{Min (i+1)}Be respectively i+1 toric largest refractive index and minimum refractive index.

In super material of the present invention, adjacent two toric largest refractive indexs and minimum refractive index satisfy: n _{Max (i)}-n _{Min (i)}=n _{Max (i+1)}-n _{Min (i+1)}

In super material of the present invention, adjacent three toric largest refractive indexs and minimum refractive index satisfy: n _{Max (i+1)}-n _{Min (i)}＞n _{Max (i+2)}-n _{Min (i+1)}

In super material of the present invention, i toric refractive index satisfies:

$n_i\left(\mathrm{\θ}\right)=\frac{\sin \mathrm{\θ}}{d\×\mathrm{\θ}}(n_{\max \left(i\right)}\×d+s-\frac{s}{\cos \mathrm{\θ}})$

Wherein, θ be on radiation source and i the torus bottom surface any line and perpendicular to the angle between the straight line of super material.

In super material of the present invention, the bus of each toric side surface is arc section.

In super material of the present invention, the bus of i toric outer surface is arc section, wherein the vertical line of the line of any and described super material are the center of circle of described arc section away from the intersection point of the one side of described radiation source on radiation source and i the torus bottom surface excircle, and the vertical line section on described intersection point and the torus bottom surface excircle between a bit is the radius of described arc section.

In super material of the present invention, the bus of i toric inner surface is arc section, wherein the vertical line of the line of any and described super material are the center of circle of described arc section away from the intersection point of the one side of described radiation source on radiation source and i the torus bottom surface inner periphery, vertical line section on described intersection point and the torus bottom surface excircle between any is the radius of described arc section, wherein i 〉=2.

In super material of the present invention, described super material is used for the electromagnetic wave of described radiation source emission is converted to plane wave.

In super material of the present invention, described super material both sides are provided with impedance matching layer.

Implement technical scheme 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, thereby greatly reduce refraction, diffraction and the reflection effect of saltus step place, alleviated and interfere with each other the problem of bringing, so that super material has more excellent performance.

Description of drawings

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

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

Fig. 2 is that the super material according to one embodiment of the invention converges electromagnetic schematic diagram;

Fig. 3 is the structural representation of super material 10 shown in Figure 2;

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

Fig. 5 is the organigram of annulus section shown in Figure 4;

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

Fig. 7 is the refractive index profile on the yz plane.

Embodiment

Fig. 2 is that the super material according to one embodiment of the invention converges electromagnetic schematic diagram, and the super material 10 with electromagnetic wave aggregation feature is used for the electromagnetic wave of radiation source 20 emissions is converted to plane wave.

As common practise we as can be known, electromagnetic refractive index with

Proportional, when a branch of electromagnetic wave propagates into another medium by a kind of medium, electromagnetic wave can reflect, when the refraction index profile of material inside is non-homogeneous, electromagnetic wave will be to the larger position deviation of refractive index ratio, by designing the electromagnetic parameter of every bit in the super material, just can adjust the refraction index profile of super material, and then reach the purpose that changes the electromagnetic wave propagation path.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 structural representation of super material 10 shown in Figure 2, and it is curved surface and the concentric circles ring body that fits tightly each other that super material 10 is divided into a plurality of side surfaces; Each toric bottom surface radius is less than the end face radius; Electromagnetic wave through behind the described super material in the parallel ejaculation of each toric end face.If the line of any and be θ perpendicular to the angle between the straight line of super material on radiation source and i the torus bottom surface, the curved surface in unique corresponding i the torus of angle theta, and the refractive index of everywhere is all identical on the curved surface of the unique correspondence of angle theta; Each toric refractive index is along with the increase of angle theta reduces gradually.Super material itself can also not be a plurality of toric combinations when practical application, but a super material monolithic will satisfy refraction index profile rule mentioned above when just designing.Above for convenience of description, will surpass material and be divided into a plurality of torus, but not as limitation of the present invention.

Be understandable that, the 1st torus is the filled circles ring body, also namely only has a curved surface shape side surface.Except first torus, other are and comprise two side surfaces (inner surface and outer surface).As shown in Figure 3.Super material shown in Fig. 3 comprises 3 torus (101,102,103), and in order clearly to represent each toric structure in the super material 10, Fig. 3 illustrates with the form of explosive view.When reality was used, 3 torus fitted tightly and consist of a complete super material together.The toric quantity here is only for signal, not as limitation of the present invention.Torus 101 is the 1st torus, and torus 102 is the 2nd torus, and torus 103 is the 3rd torus.Fig. 4 shows the end view of the super material 10 that comprises 3 torus (101,102,103).The thickness of super material 10 is shown in figure d, and L represents the straight line perpendicular to super material.As shown in Figure 3, each toric end view is arc section, and the refractive index on the identical arc section is identical, and also namely the refractive index on the formed toric curved surface of this arc section is identical.

If the line of any and be θ perpendicular to the angle between the straight line of super material on radiation source and i the torus bottom surface excircle _i, i is positive integer and less the closer to i corresponding to the torus of super material center; Wherein, angle theta _iSatisfy following formula:

$\sin c\left({\mathrm{\θ}}_i\right)=\frac{d}{\mathrm{\λ}}(n_{\max (i+1)}-n_{\min \left(i\right)});$

$s\×(\frac{1}{\cos {\mathrm{\θ}}_i}-\frac{1}{\cos {\mathrm{\θ}}_{i-1}})=\frac{d}{\sin c\left({\mathrm{\θ}}_{i-1}\right)}{n}_{\max \left(i\right)}-\frac{d}{\sin c\left({\mathrm{\θ}}_i\right)}{n}_{\min \left(i\right)});$

Wherein, $\sin c\left({\mathrm{\θ}}_i\right)=\frac{\sin \left({\mathrm{\θ}}_i\right)}{{\mathrm{\θ}}_i},$ $\sin c\left({\mathrm{\θ}}_{i-1}\right)=\frac{\sin \left({\mathrm{\θ}}_{i-1}\right)}{{\mathrm{\θ}}_{i-1}},$ θ ₀=0; S is that described radiation source is to the distance of described super material; D is the thickness of described super material; λ is electromagnetic wavelength, n _{Max (i)}, n _{Min (i)}Be respectively i toric largest refractive index and minimum refractive index, n _{Max (i+1)}, n _{Min (i+1)}Be respectively i+1 toric largest refractive index and minimum refractive index.Adjacent two toric largest refractive indexs and minimum refractive index satisfy: n _{Max (i)}-n _{Min (i)}=n _{Max (i+1)}-n _{Min (i+1)}Angle theta or θ _iSpan is

As shown in Figure 5, establish n _{Max (1)}, n _{Min (1)}Known, the 1st toric θ ₁And n _{Max (2)}Available following formula calculates:

$\sin c\left({\mathrm{\θ}}_1\right)=\frac{d}{\mathrm{\λ}}(n_{\max \left(2\right)}-n_{\min \left(1\right)});$

$s\×(\frac{1}{\cos {\mathrm{\θ}}_1}-1)=\frac{d}{\sin c\left({\mathrm{\θ}}_0\right)}{n}_{\max \left(1\right)}-\frac{d}{\sin c\left({\mathrm{\θ}}_1\right)}{n}_{\min \left(1\right)}).$

The 2nd toric θ ₂And n _{Max (3)}Available following formula calculates:

$\sin c\left({\mathrm{\θ}}_2\right)=\frac{d}{\mathrm{\λ}}(n_{\max \left(3\right)}-n_{\min \left(2\right)});$

$s\×(\frac{1}{\cos {\mathrm{\θ}}_2}-\frac{1}{\cos {\mathrm{\θ}}_1})=\frac{d}{\sin c\left({\mathrm{\θ}}_1\right)}{n}_{\max \left(2\right)}-\frac{d}{\sin c\left({\mathrm{\θ}}_2\right)}{n}_{\min \left(2\right)}).$

The 3rd toric θ ₃Available following formula calculates:

$\sin c\left({\mathrm{\θ}}_3\right)=\frac{d}{\mathrm{\λ}}(n_{\max \left(4\right)}-n_{\min \left(3\right)});$

$s\×(\frac{1}{\cos {\mathrm{\θ}}_3}-\frac{1}{\cos {\mathrm{\θ}}_2})=\frac{d}{\sin c\left({\mathrm{\θ}}_2\right)}{n}_{\max \left(3\right)}-\frac{d}{\sin c\left({\mathrm{\θ}}_3\right)}{n}_{\min \left(3\right)}).$

In an embodiment of the present invention, adjacent three toric largest refractive indexs and minimum refractive index satisfy: n _{Max (i+1)}-n _{Min (i)}＞n _{Max (i+2)}-n _{Min (i+1)}

As shown in Figure 5, the bus of each toric side surface (comprising outer surface and inner surface) is arc section.The bus of i toric outer surface is arc section, and the arc section of end view is the bus of each torus outer surface among the figure.For the refractive index more clearly described on the identical curved surface is identical, the curved surface of torus inside is also set forth.Wherein the vertical line of the line of any and described super material are the center of circle of described arc section away from the intersection point of the one side of described radiation source on radiation source and i the torus bottom surface excircle, and the vertical line section on described intersection point and the torus bottom surface excircle between a bit is the radius of described arc section.

The bus of i toric inner surface is arc section, wherein the vertical line of the line of any and described super material are the center of circle of described arc section away from the intersection point of the one side of described radiation source on radiation source and i the torus bottom surface inner periphery, vertical line section on described intersection point and the torus bottom surface excircle between any is the radius of described arc section, wherein i 〉=2.First torus is solid, does not have inner surface.I+1 toric inner surface fits tightly in i toric outer surface, and also namely i+1 toric inner surface is identical with the curvature everywhere of i toric outer surface.The refractive index of each toric inner surface is maximum, and the refractive index of outer surface is minimum.

Any line and the angle between the L are θ on radiation source and the 1st the torus bottom surface excircle ₁, the vertical line V of the line of any on radiation source and the 1st the torus bottom surface excircle ₁With the intersection point of the another side of super material be O ₁, the bus of the 1st torus outer surface is m1; M1 is with O ₁Be the center of circle, V ₁For radius rotates the annulus section of coming.In like manner, line and the angle between the L of any is θ on radiation source and the 2nd the torus bottom surface excircle ₂, the vertical line V of the line of any on radiation source and the 2nd the torus bottom surface excircle ₂With the intersection point of the another side of super material be O ₂, the bus of the 2nd torus outer surface is m2; M2 is with O ₂Be the center of circle, V ₂For radius rotates the annulus section of coming; Any line and the angle between the L are θ on radiation source and the 3rd the torus bottom surface excircle ₃, the vertical line V of the line of any on radiation source and the 3rd the torus bottom surface excircle ₃With the intersection point of the another side of super material be O ₃, the bus of the 3rd torus outer surface is m3; M3 is with O ₃Be the center of circle, V ₃For radius rotates the annulus section of coming.As shown in Figure 5, annulus section m1, m2, m3 are symmetrical with respect to L.

For arbitrary torus, establish on radiation source and i the torus bottom surface line of any and be θ perpendicular to the angle between the straight line of super material, i toric refractive index n _i(θ) Changing Pattern along with θ satisfies:

$n_i\left(\mathrm{\θ}\right)=\frac{\sin \mathrm{\θ}}{d\×\mathrm{\θ}}(n_{\max \left(i\right)}\×d+s-\frac{s}{\cos \mathrm{\θ}})$

Wherein, n _{Max (i)}Be i toric largest refractive index.Curved surface in unique corresponding i the torus of angle theta, and the refractive index of everywhere is all identical on the curved surface of the unique correspondence of angle theta.

As shown in Figure 5, take the 1st torus as example, certain any line and be θ perpendicular to the angle between the straight line of super material on radiation source and the 1st the torus bottom surface, the intersection point of the another side of the vertical line V of the line of this point and super material is O on radiation source and the 1st the torus bottom surface, bus m be take O as the center of circle, the annulus section come as the radius rotation of V.Curved surface in unique corresponding the 1st torus of angle theta, this curved surface is rotated around L by bus m, and the refractive index of everywhere is all identical on this curved surface of the unique correspondence of angle theta.

Super material can be used for the electromagnetic wave of described radiation source emission is converted to plane wave.Its each toric refractive index along with the increase of angle from n _{Max (i)}Be reduced to n _{Min (i)}, the schematic diagram of variations in refractive index as shown in Figure 6.

Super material can be designed as a plurality of super sheet of material when the structural design of reality, each lamella comprises the substrate and a plurality of artificial micro-structural or the artificial pore structure that are attached on the described substrate of sheet.A plurality of super sheet of material combine that the refraction index profile of rear integral body need to satisfy or approximately satisfy above-mentioned formula, so that the refraction index profile on same curved surface is identical, the busbar of curved surface is circular arc.Certainly, when actual design, may be designed to relatively difficulty of accurate circular arc, can be designed to as required the circular arc that is similar to or stepped, 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 super design of material technique and realize that refractive index provided by the invention arranges.

For artificial micro-structural, plane with geometrical pattern or the stereochemical structure of each described artificial micro-structural for being comprised of wire is such as but not limited to " ten " font, plane flakes, stereo snow flake shape.Wire can be copper wire or filamentary silver, can be attached on the substrate by etching, plating, brill quarter, photoetching, electronics is carved or ion is carved method.A plurality of artificial micro-structurals in the super material so that the refractive index of super material reduce along with the increase of angle theta.In the situation that incident electromagnetic wave is determined, artificial micro-structural the arranging in electromagnetic wave converging element of topological pattern and different size by the artificial micro-structural of appropriate design, just can adjust the refraction index profile of super 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 more intuitively super sheet of material refractive index refractive index regularity of distribution on the yz face, 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 closeer refractive index of line is larger, then meet above all relational expressions super material refraction index profile as shown in Figure 7.

Previously described super material can be shape shown in Figure 3, can certainly be other shapes that need, and gets final product so long as can satisfy previously described variations in refractive index rule.Super material of the present invention can use as lens, also can be used for the antenna of the communications field, and is of many uses.

Super material itself can also not be a plurality of toric combinations when practical application, but a super material monolithic will satisfy refraction index profile rule mentioned above when just designing.Above for convenience of description, will surpass material and be divided into a plurality of torus, but not as limitation of the present invention.

When practical application, for so that the performance of super material is better, reduce reflection, can be super material both sides all arrange impedance matching layer.Content about impedance matching layer can referring to the prior art data, repeat no more herein.

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

The above is described embodiments of the invention by reference to the accompanying drawings; but the present invention is not limited to above-mentioned embodiment; above-mentioned embodiment only is schematic; rather than restrictive; those of ordinary skill in the art is under enlightenment of the present invention; not breaking away from 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. a super material is characterized in that, it is curved surface and the concentric circles ring body that fits tightly each other that described super material is divided into a plurality of side surfaces; Each toric bottom surface radius is less than the end face radius; Electromagnetic wave through behind the described super material in the parallel ejaculation of each toric end face;

If the line of any and be θ perpendicular to the angle between the straight line of super material on radiation source and i the torus bottom surface, the curved surface in unique corresponding i the torus of angle theta, and the refractive index of everywhere is all identical on the curved surface of the unique correspondence of angle theta; Each toric refractive index is along with the increase of angle theta reduces gradually.

2. super material according to claim 1 is characterized in that, establishes on radiation source and i the torus bottom surface excircle line of any and is θ perpendicular to the angle between the straight line of super material _i, i is positive integer and less the closer to i corresponding to the torus of super material center; Wherein, angle theta _iSatisfy following formula:

$\sin c\left({\mathrm{\θ}}_i\right)=\frac{d}{\mathrm{\λ}}(n_{\max (i+1)}-n_{\min \left(i\right)});$

$s\×(\frac{1}{\cos {\mathrm{\θ}}_i}-\frac{1}{\cos {\mathrm{\θ}}_{i-1}})=\frac{d}{\sin c\left({\mathrm{\θ}}_{i-1}\right)}{n}_{\max \left(i\right)}-\frac{d}{\sin c\left({\mathrm{\θ}}_i\right)}{n}_{\min \left(i\right)});$

Wherein, $\sin c\left({\mathrm{\θ}}_i\right)=\frac{\sin \left({\mathrm{\θ}}_i\right)}{{\mathrm{\θ}}_i},$ $\sin c\left({\mathrm{\θ}}_{i-1}\right)=\frac{\sin \left({\mathrm{\θ}}_{i-1}\right)}{{\mathrm{\θ}}_{i-1}},$ θ ₀=0; S is that described radiation source is to the distance of described super material; D is the thickness of described super material; λ is electromagnetic wavelength, n _{Max (i)}, n _{Min (i)}Be respectively i toric largest refractive index and minimum refractive index, n _{Max (i+1)}, n _{Min (i+1)}Be respectively i+1 toric largest refractive index and minimum refractive index.

3. super material according to claim 2 is characterized in that, adjacent two toric largest refractive indexs and minimum refractive index satisfy: n _{Max (i)}-n _{Min (i)}=n _{Max (i+1)}-n _{Min (i+1)}

4. super material according to claim 3 is characterized in that, adjacent three toric largest refractive indexs and minimum refractive index satisfy: n _{Max (i+1)}-n _{Min (i)}＞n _{Max (i+2)}-n _{Min (i+1)}

5. super material according to claim 2 is characterized in that, i toric refractive index satisfies:

$n_i\left(\mathrm{\θ}\right)=\frac{\sin \mathrm{\θ}}{d\×\mathrm{\θ}}(n_{\max \left(i\right)}\×d+s-\frac{s}{\cos \mathrm{\θ}})$

Wherein, θ be on radiation source and i the torus bottom surface any line and perpendicular to the angle between the straight line of super material.

6. super material according to claim 5 is characterized in that, the bus of each toric side surface is arc section.

7. super material according to claim 5, it is characterized in that, the bus of i toric outer surface is arc section, wherein the vertical line of the line of any and described super material are the center of circle of described arc section away from the intersection point of the one side of described radiation source on radiation source and i the torus bottom surface excircle, and the vertical line section on described intersection point and the torus bottom surface excircle between a bit is the radius of described arc section.

8. super material according to claim 5, it is characterized in that, the bus of i toric inner surface is arc section, wherein the vertical line of the line of any and described super material are the center of circle of described arc section away from the intersection point of the one side of described radiation source on radiation source and i the torus bottom surface inner periphery, vertical line section on described intersection point and the torus bottom surface excircle between any is the radius of described arc section, wherein i 〉=2.

9. each described super material is characterized in that according to claim 1～8, and described super material is used for the electromagnetic wave of described radiation source emission is converted to plane wave.

10. each described super material is characterized in that according to claim 1～8, and described super material both sides are provided with impedance matching layer.

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