CN102480019A - Metamaterial antenna - Google Patents

Abstract

The invention relates to a metamaterial antenna which comprises a vibrator, a metamaterial film layer and a reflector, wherein the vibrator is used for generating electromagnetic waves; the metamaterial film layer is used for converging the electromagnetic waves generated by the vibrator and outwards radiating the electromagnetic waves and is also used for converting spherical electromagnetic waves generated by the vibrator into planar electromagnetic waves, and comprises a plurality of metamaterial sheet layers; and the reflector is used for reflecting partial electromagnetic waves generated by the vibrator to the metamaterial film layer, is a cover-free cavity and forms a closed cavity together with the metamaterial film layer, and the vibrator is arranged in the reflector. Through changing the refractive index distribution condition inside the metamaterial film layer, the invention ensures that a half-power bandwidth of an antenna far field is reduced, further propagating distance of the antenna is increased, and front-to-back ratio of the antenna is increased.

Description

A kind of ultra material antenna

Technical field

The present invention relates to ultra field of materials, relate in particular to a kind of ultra material antenna.

Background technology

Half-power angle is also claimed 3dB beamwidth, half-power beam width, half-power bandwidth.In the power radiation pattern, in a certain plane that comprises main lobe greatest irradiation direction, the angle that drops to relative greatest irradiation direction power flux-density between 2 of half place (or less than maximum 3dB) calls half-power beam width.In the field strength pattern, in a certain plane that comprises main lobe greatest irradiation direction, drop to 0.707 times of angle of locating to relative greatest irradiation direction field intensity and be also referred to as half-power beam width.The horizontal plane half-power beam width is meant the half-power beam width of horizontal radiation pattern, and the vertical plane half-power beam width is meant the half-power beam width of elevation radiation patytern.In directional antenna, the distance that antenna is propagated is by the decision of vertical plane half-power beam width, and promptly the vertical plane half-power bandwidth is more little; The gain of antenna is just big more, and the signal propagation distance of antenna emission is just far away more, otherwise; The gain of antenna is just more little, and the distance that signal is propagated is also just near more.

The method of improving half-power bandwidth in the prior art generally has: the dielectric coatings method.The dielectric coatings method adopts the form of antenna protecting equipment to be carried in the front end of aerial array, and this method can improve the gain about aerial array 3db, makes half-power bandwidth become 36 ° and make the directivity of antenna improve.But when the signal long-distance transmissions, half-power bandwidth cannot reach our demand, sets up some base stations or relay station again in order to satisfy long range signals transmission needs, and the cost that strengthens so also all makes troubles to signal emission or acceptance.

Summary of the invention

The objective of the invention is to solve prior art antenna half-power bandwidth problem of smaller; A kind of ultra material antenna is provided; This antenna one surpasses the material film layer through being provided with at the antenna front end; Have less half-power bandwidth after making signal that antenna sends through ultra material film layer, reach signal and transmit and receive at a distance.

In order to achieve the above object, the following technical scheme of the present invention's employing:

A kind of ultra material antenna, said antenna comprises an oscillator, is used to generate electromagnetic waves; One surpass the material film layer, be used for the electromagnetic wave that said oscillator produces is converged the back and to external radiation, also is used for converting the sphere electromagnetic wave that said oscillator produces into plane electromagnetic wave; Said ultra material film layer is made up of a plurality of ultra sheet of material; Wherein, The ultra sheet of material near said oscillator is the first to surpass sheet of material; The said refractive index that the first surpasses sheet of material is the rounded distribution in the center of circle with its center, the first surpasses Changing Pattern such as the following expression formula of the refraction index profile of sheet of material along with radius r:

$n\left(r\right)=n_{\max }-\frac{1}{d}\{\sqrt{{(r-\frac{1}{2}d)}^2+s^2}-s\}$

N in the formula _MaxExpression the first surpasses the largest refractive index value in the sheet of material, and d representes the first to surpass the thickness of sheet of material, and s representes that said oscillator to the first surpasses the distance of sheet of material, and n (r) expression the first surpasses sheet of material inside radius r place refractive index value.

Further, said antenna also comprises a reflector, and the part reflection of electromagnetic wave that is used for oscillator is produced is in ultra material film layer, and said reflector is a uncovered cavity and the formation closed cavity that links to each other with ultra material film layer, and said oscillator is positioned at reflector.

Further, said reflector is an electric conductor.

Further, the said sheet of material that the first surpasses comprises that the substrate of sheet and cycle are arranged in a plurality of artificial micro-structural on the said substrate.

Further, in the said ultra material film layer except a plurality of ultra sheet of material that the first surpasses sheet of material all with the first to surpass sheet of material identical.

Further, said artificial micro-structural is for to form planar structure or the stereochemical structure that electromagnetic field is had response by at least one one metal wire.

Further, said wire is copper wire or filamentary silver.

Further, said wire through etching, plating, brill quarter, photoetching, electronics is carved or ion is carved method attached on the substrate.

Further, said artificial micro-structural for derive the shape of deriving of " worker " font, " worker " font, flakes or alabastrine shape any one.

Further, said substrate is made by ceramic material, epoxy resin, polytetrafluoroethylene, FR-4 composite material or F4B composite material.

The present invention is with respect to prior art; Have following beneficial effect: the present invention is through changing the inner refraction index profile situation of ultra material film layer; Make the half-power bandwidth in antenna far field reduce widely; And then promoted the distance that antenna is propagated, and also increased the front and back ratio of antenna simultaneously, make antenna have more directivity.

Description of drawings

Fig. 1 is the structural representation of a kind of ultra material antenna of the present invention;

Fig. 2 is a border circular areas sketch map in the ultra material film layer according to the invention;

Fig. 3 is a refraction index profile sketch map in the ultra sheet of material according to the invention;

Fig. 4 is another embodiment of the present invention structural representation;

Fig. 5 A is ' I-shaped ' artificial micro-structural on the ultra material film layer;

Fig. 5 B is ' flakes ' artificial micro-structural on the ultra material film layer;

Fig. 5 C is the artificial micro-structural of the another kind ' flakes ' on the ultra material film layer;

Fig. 5 D is another derived structure of a kind of concrete form ' flakes ' structure of the artificial micro-structural on the ultra material film layer;

Fig. 6 is the arrangement sketch map of artificial micro-structural in the substrate of ultra material film layer that adopts I-shape construction.

Embodiment

Below in conjunction with embodiment and accompanying drawing, the present invention is done to specify further, but execution mode of the present invention is not limited thereto.

Ultra material is a kind ofly to be elementary cell and to carry out spatial arrangement, have the new material of special electromagnetic response with ad hoc fashion with artificial micro-structural, comprises cycle artificial micro-structural of arranging and the substrate that supplies artificial micro-structural to adhere to.Artificial micro-structural is for to form planar structure or the stereochemical structure that electromagnetic wave is had response by at least one one metal wire, a plurality of artificial micro-structurals array arrangement on substrate, each artificial micro-structural with and appended the shared part of substrate be a ultra material cell.Substrate can be any and artificial micro-structural material different, and the stack of these two kinds of materials makes each ultra material cell produce an effective dielectric constant and magnetic permeability, these two physical parameters the are corresponding respectively electric field response and the magnetic responsiveness of ultra material cell.Ultra material is to be determined by artificial features of microstructures to the characteristic of electromagnetic response, and the topological characteristic that the electromagnetic response of artificial micro-structural depends on its pattern wiry to a great extent and had and its physical dimension.According to the topological graph and the physical dimension of each artificial micro-structural of arranging in the ultra material space of above-mentioned principle design, just can the electromagnetic parameter of every bit in the ultra material be provided with.

See also Fig. 1, a kind of ultra material antenna comprises an oscillator 10, ultra material film layer 20 and reflector 30.Said reflector 30 is a uncovered cavity, and said ultra material film layer 20 constitutes a closed cavity with reflector 30, and said oscillator 10 places in the reflector 30.

Oscillator 10 is used for radiated electromagnetic wave; Wherein most of electromagnetic wave directly gets into to reflect in the ultra material film layer 20 and converges; And convert plane electromagnetic wave into; Convert plane electromagnetic wave into after converging through ultra material film layer 20 refraction after also having the part electromagnetic wave of lacking through reflector 30 reflections, in this execution mode, reflector 30 is an electric conductor again.

The refraction aggregation feature of ultra material film layer 20 is to realize through the refraction index profile that designs in it; Said ultra material film layer 20 is made up of a plurality of ultra sheet of material, and substrate and cycle that said each ultra sheet of material includes sheet are arranged in a plurality of artificial micro-structural on the said substrate.

With Fig. 1 is example, and ultra material film layer 20 comprises and the first surpasses sheet of material 201, the second surpasses sheet of material 202, and three surpass sheet of material 203.As shown in Figure 2, the refractive index of each ultra sheet of material is the rounded distribution in the center of circle with its center all.

Said refraction index profile rule such as the following expression formula of sheet of material 201 in its border circular areas that the first surpass:

$n\left(r\right)=n_{\max }-\frac{1}{d}\{\sqrt{{(r-\frac{1}{2}d)}^2+s^2}-s\}$

N in its Chinese style _MaxExpression the first surpasses the largest refractive index value in the sheet of material, and d representes the first to surpass the thickness of sheet of material, and s representes that said oscillator to the first surpasses the distance of sheet of material, and n (r) expression the first surpasses sheet of material inside radius r place refractive index value.

In this execution mode, said ultra material film layer 20 can be designed to the refraction index profile of incident electromagnetic wave as shown in Figure 3, according to above-mentioned formula:

$n\left(r\right)=n_{\mathrm{Max}}-\frac{1}{d}\{\sqrt{{(r-\frac{1}{2}d)}^2+s^2}-s\}$ Can know,

n ₁＞n ₂＞n ₃＞...＞n _p, m is greater than 3 natural numbers smaller or equal to q.

A plurality of ultra sheet of material in the ultra material film layer 20 is all with the first to surpass sheet of material 201 identical, promptly the second surpasses sheet of material 202 and the and three surpasses sheet of material 203 all with the first to surpass sheet of material 201 identical.

We know that usually the refractive index formula is also like this for the refractive index of

ultra material; Just the refractive index of ultra material square is directly proportional with the dielectric constant and the magnetic permeability of material; The magnetic permeability of conventional dielectric material is general to be changed not quite; Can regard a constant value as; So the refractive index of ultra material is only relevant with the dielectric constant of ultra material to a great extent, dielectric constant is big more, and the refractive index of ultra material is just big more.

Through theoretical and actual proof; The dielectric constant of ultra material is relevant with the artificial micro-structural shape and size in substrate and the substrate; Substrate adopts dielectric insulation material to process; Can be ceramic material, macromolecular material, ferroelectric material, ferrite material, ferromagnetic material etc., macromolecular material for example can be, epoxy resin or polytetrafluoroethylene.Artificial micro-structural is attached to the metal wire that response can be arranged electromagnetic wave on the substrate with certain geometry; Metal wire can be that section is the copper cash of cylindric or flat, silver-colored line etc.; The general copper that adopts, because copper wire is relatively cheap, the section of metal wire also can be other shapes certainly; Metal wire through etching, plating, brill quarter, photoetching, electronics is carved or ion quarter etc. technology attached on the substrate; Whole ultra sheet of material be divided into a plurality of unit (comprise in this unit substrate and attached to the artificial micro-structural on this cell substrate), each unit all has an artificial micro-structural, each unit all can produce response to the electromagnetic wave through wherein; Thereby influence electromagnetic wave transmission therein; The size of each unit depends on the electromagnetic wave of needs responses, be generally required response electromagnetic wavelength 1/10th, can not be regarded as in the space continuously otherwise comprise being arranged in that the unit of artificial micro-structural forms in the space.

Under the situation that substrate is selected,, can adjust everywhere effective dielectric constant and equivalent permeability and then the ultra material of change equivalent refractive index everywhere on the ultra material through pattern, size and the spatial distribution on substrate thereof of adjusting artificial micro-structural.When artificial micro-structural adopted identical geometry, the size of the artificial micro-structural in somewhere was big more, and the effective dielectric constant that then should locate is big more, and refractive index is also big more.

The pattern of the artificial micro-structural that present embodiment adopts is I-shaped, and shown in Fig. 5 A, the distribution of artificial micro-structural on substrate is as shown in Figure 6; Can know that by Fig. 6 the size of the artificial micro-structural of flakes therefrom diminishes around the mind-set gradually on the substrate, locates in substrate center; The size of alabastrine artificial micro-structural is maximum; And measure-alike in the artificial micro-structural of flakes at distance center same radius place, thus the effective dielectric constant of substrate by the centre to around diminish gradually, middle effective dielectric constant is maximum; Thereby the refractive index of substrate from the centre to around diminish gradually, the refractive index of mid portion is maximum.

Combine accompanying drawing that embodiments of the invention are described above; But the present invention is not limited to above-mentioned embodiment; The pattern of artificial micro-structural can be two dimension, also can be three-dimensional structure that " worker " font (shown in Fig. 5 A) that is not limited to use among this embodiment can be the derived structure of " worker " font; It can be the alabastrine derived structure shown in each the orthogonal flakes in bar limit in three dimensions shown in Fig. 5 B and Fig. 5 C and Fig. 5 D; Also can be other geometry, wherein different artificial micro-structurals can be that pattern is identical, but its design size is different; Also can be that pattern and design size are all inequality.The quantity that constitutes the substrate of ultra material can increase as required and can subtract, and the structure of each plate base can be identical, also can be different, as long as can parallel ejaculation after the satisfied electromagnetic wave that is sent by antenna element is propagated through ultra material panel.

As shown in Figure 4 is another embodiment of a kind of ultra material antenna of the present invention; This antenna comprises: five oscillators 10 ', ultra material film layer 20 ' and reflector 30 '; Said five oscillators 10 ' be arranged in side by side reflector 30 '; Said ultra material film layer 20 ' with reflector 30 ' closed cavity of formation, wherein, ultra material film layer 20 ' the be ultra material film layer 20 among five first embodiment composition of arranging side by side.

Five oscillators 10 ' launch sphere electromagnetic wave major part directly to converge and convert into plane electromagnetic wave through ultra material film layer 20 ' refraction; Radiate then; Converge and convert into plane electromagnetic wave, radiate at last through ultra material film layer 20 ' refraction behind all the other few part electromagnetic waves process reflector 30 ' reflection gains.

Ultra material film layer 20 in the present embodiment ' structure with and the inner refractive index regularity of distribution all with first embodiment in ultra material film layer 20 identical.

This present invention makes the half-power bandwidth in antenna far field reduce through changing the inner refraction index profile situation of ultra material film layer in sum, and then has promoted the distance that antenna is propagated, and has also increased the front and back ratio of antenna simultaneously.

The foregoing description is a preferred implementation of the present invention; But execution mode of the present invention is not restricted to the described embodiments; Other any do not run counter to change, the modification done under spirit of the present invention and the principle, substitutes, combination, simplify; All should be the substitute mode of equivalence, be included within protection scope of the present invention.

Claims (10)

1. ultra material antenna, said antenna comprises an oscillator, is used to generate electromagnetic waves; One surpass the material film layer, be used for the electromagnetic wave that said oscillator produces is converged the back and to external radiation; It is characterized in that; Said ultra material film layer is made up of a plurality of ultra sheet of material; Wherein, The ultra sheet of material near said oscillator is the first to surpass sheet of material, and the said refractive index that the first surpasses sheet of material is the rounded distribution in the center of circle with its center, the first surpasses Changing Pattern such as the following expression formula of the refraction index profile of sheet of material along with radius r:

$n\left(r\right)=n_{\max }-\frac{1}{d}\{\sqrt{{(r-\frac{1}{2}d)}^2+s^2}-s\}$

N in the formula _MaxExpression the first surpasses the largest refractive index value in the sheet of material, and d representes the first to surpass the thickness of sheet of material, and s representes that said oscillator to the first surpasses the distance of sheet of material, and n (r) expression the first surpasses sheet of material inside radius r place refractive index value.

2. a kind of ultra material antenna according to claim 1; It is characterized in that; Said antenna also comprises a reflector; The part reflection of electromagnetic wave that is used for oscillator is produced is in ultra material film layer, and said reflector is a uncovered cavity and the formation closed cavity that links to each other with ultra material film layer, and said oscillator is positioned at reflector.

3. a kind of ultra material antenna according to claim 2 is characterized in that said reflector is an electric conductor.

4. a kind of ultra material antenna according to claim 1 is characterized in that, the said sheet of material that the first surpasses comprises that the substrate of sheet and cycle are arranged in a plurality of artificial micro-structural on the said substrate.

5. a kind of ultra material antenna according to claim 1 is characterized in that, in the said ultra material film layer except a plurality of ultra sheet of material that the first surpasses sheet of material all with the first to surpass sheet of material identical.

6. a kind of ultra material antenna according to claim 4 is characterized in that said artificial micro-structural is for to form planar structure or the stereochemical structure that electromagnetic field is had response by at least one one metal wire.

7. a kind of ultra material antenna according to claim 6 is characterized in that said wire is copper wire or filamentary silver.

8. a kind of ultra material antenna according to claim 7 is characterized in that, said wire through etching, plating, brill quarter, photoetching, electronics is carved or ion is carved method attached on the substrate.

9. a kind of ultra material antenna according to claim 7 is characterized in that, said artificial micro-structural for derive the shape of deriving of " worker " font, " worker " font, flakes or alabastrine shape any one.

10. a kind of ultra material antenna according to claim 4 is characterized in that said substrate is made by ceramic material, epoxy resin, polytetrafluoroethylene, FR-4 composite material or F4B composite material.

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