CN102480019B - 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 super material antenna

Technical field

The present invention relates to super Material Field, relate in particular to a kind of super material antenna.

Background technology

Half-power angle also claims 3dB beamwidth, half-power beam width, half-power bandwidth.In power radiation pattern, in a certain plane that comprises main lobe greatest irradiation direction, the angle that relative greatest irradiation direction power flux-density is dropped between 2 of half place (or less than maximum 3dB) calls half-power beam width.In field strength pattern, in a certain plane that comprises main lobe greatest irradiation direction, relative greatest irradiation direction field intensity is dropped to 0.707 times of angle of locating also referred to as half-power beam width.The horizontal plane half-power beam width refers to the half-power beam width of horizontal radiation pattern, and the vertical plane half-power beam width refers to 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 namely the vertical plane half-power bandwidth is less, the gain of antenna is just larger, and the signal propagation distance of antenna transmission is just far away, otherwise, the gain of antenna is just less, and the distance that signal is propagated is also just nearer.

The method of improving half-power bandwidth in 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 of aerial array 3db left and right, 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 in order to satisfy long range signals transmission needs again, and the cost that strengthens so also all makes troubles to signal emission or acceptance.

Summary of the invention

The object of the invention is to solve the less problem of prior art antenna half-power bandwidth, a kind of super material antenna is provided, this antenna one surpasses the material film layer by arranging at the antenna front end, have less half-power bandwidth after making signal that antenna sends by super material film layer, reach signal distance transmission and reception.

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

A kind of super material antenna, described antenna comprises an oscillator, for generation of electromagnetic wave; One surpass the material film layer, after being used for the electromagnetic wave that described oscillator produces is converged and to external radiation, also be used for the sphere electromagnetic wave that described oscillator produces is converted to plane electromagnetic wave; Described super material film layer is comprised of a plurality of super sheet of material, wherein, super sheet of material near described oscillator is the first to surpass sheet of material, the described refractive index rounded distribution take its center as the center of circle that the first surpasses sheet of material the first surpasses the refraction index profile of sheet of material along with Changing Pattern such as the following formula of radius r:

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

N in formula _maxExpression the first surpasses largest refractive index value in sheet of material, and d represents the first to surpass the thickness of sheet of material, and s represents that described 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, described antenna also comprises a reflector, and the part reflection of electromagnetic wave that is used for oscillator is produced is in super material film layer, and described reflector is a uncovered cavity and the formation closed cavity that is connected with super material film layer, and described oscillator is positioned at reflector.

Further, described reflector is electric conductor.

Further, the described 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 described substrate.

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

Further, described artificial micro-structural is for to be comprised of at least one one metal wire planar structure or the stereochemical structure that electromagnetic field is had response.

Further, described wire is copper wire or filamentary silver.

Further, described wire is attached on substrate by etching, plating, brill quarter, photoetching, electronics is carved or ion is carved method.

Further, described artificial micro-structural be derivative shape, flakes or the alabastrine derivative shape of " work " font, " work " font any one.

Further, described 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 surpasses the refraction index profile situation of material film layer inside by change, make the half-power bandwidth of Antenna Far Field reduce widely, and then promoted the distance that antenna is propagated, also increase simultaneously the front and back ratio of antenna, made antenna have more directivity.

Description of drawings

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

Fig. 2 is circular area schematic in super material film layer of the present invention;

Fig. 3 is refractive index distribution schematic diagram in super sheet of material of the present invention;

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

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

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

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

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

Fig. 6 is the arrangement schematic diagram of artificial micro-structural in the substrate of super material film layer that adopts I-shape construction.

Embodiment

Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention are not limited to this.

Super material is a kind ofly to carry out spatial arrangement, have the new material of special electromagnetic response take artificial micro-structural as elementary cell and with ad hoc fashion, comprises the artificial micro-structural that the cycle arranges and the substrate that adheres to for artificial micro-structural.Artificial micro-structural is for to be comprised of at least one one metal wire planar structure or the stereochemical structure that electromagnetic wave is had response, a plurality of artificial micro-structurals array arrangement on substrate, each artificial micro-structural with and the accompanying shared part of substrate be a super material cell.Substrate can be the different material of any and artificial micro-structural, and the stack of this bi-material makes each super material cell produce an effective dielectric constant and magnetic permeability, these two physical parameters are corresponding respectively electric field response and the magnetic responsiveness of super material cell.Super material is that feature by artificial micro-structural is determined to the feature of electromagnetic response, and the electromagnetic response of artificial micro-structural depends on topological characteristic and its physical dimension that its pattern wiry has to a great extent.Topological graph and the physical dimension of each artificial micro-structural of arranging in material space super according to above-mentioned principle design just can arrange the electromagnetic parameter of every bit in super material.

See also Fig. 1, a kind of super material antenna comprises an oscillator 10, super material film layer 20 and reflector 30.Described reflector 30 is a uncovered cavity, and described super material film layer 20 consists of a closed cavity with reflector 30, and described oscillator 10 is placed in reflector 30.

Oscillator 10 is used for radiated electromagnetic wave, wherein most of electromagnetic wave directly enters to reflect in super material film layer 20 and converges, and be converted to plane electromagnetic wave, be converted to plane electromagnetic wave after converging through super material film layer 20 refraction again after also having the small part electromagnetic wave by reflector 30 reflections, in the present embodiment, reflector 30 is electric conductor.

The refraction aggregation feature of super material film layer 20 is to realize by the refraction index profile that designs in it, described super material film layer 20 is comprised of a plurality of super sheet of material, and described each super sheet of material includes the substrate of sheet and cycle and is arranged in a plurality of artificial micro-structural on described substrate.

Take Fig. 1 as example, super 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, all rounded distributions take its center as the center of circle of the refractive index of each super sheet of material.

Described refraction index profile rule such as the following 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 largest refractive index value in sheet of material, and d represents the first to surpass the thickness of sheet of material, and s represents that described 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 the present embodiment, described super 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:

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

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

A plurality of super sheet of material in super material film layer 20 is all with the first to surpass sheet of material 201 identical, namely 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

The refractive index of super material is also like this, namely the refractive index of super material square is directly proportional to 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 super material is only relevant to the dielectric constant of super material to a great extent, dielectric constant is larger, and the refractive index of super material is just larger.

Through theoretical and actual proof, the dielectric constant of super material is relevant with the artificial micro-structural shape and size in substrate and substrate, substrate adopts dielectric insulation material to make, can be ceramic material, macromolecular material, ferroelectric material, ferrite material, ferromagnetic material etc., macromolecular material can be for example, epoxy resin or polytetrafluoroethylene.artificial micro-structural can have to electromagnetic wave the metal wire of response for being attached to certain geometry on substrate, metal wire can be that section is the copper cash of cylindric or flat, silver line etc., the general copper that adopts, because copper wire is relatively cheap, certainly the section of metal wire also can be other shapes, metal wire is by etching, electroplate, bore and carve, photoetching, electronics carve or ion quarter etc. technique be attached on substrate, whole super sheet of material is divided into a plurality of unit (comprising substrate and the artificial micro-structural that is attached on this cell substrate in this unit), each unit has an artificial micro-structural, each unit can produce response to the electromagnetic wave that passes through wherein, thereby affect electromagnetic wave transmission therein, the size of each unit depends on the electromagnetic wave of needs response, be generally required response electromagnetic wavelength 1/10th, otherwise being arranged in that the unit that comprises artificial micro-structural in the space forms can not be regarded as in the space continuously.

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

the pattern of the artificial micro-structural that the present embodiment adopts is I-shaped, as shown in Fig. 5 A, the distribution of artificial micro-structural on substrate as shown in Figure 6, as shown in Figure 6, on substrate, the size of the artificial micro-structural of flakes therefrom diminishes around mind-set gradually, locate 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, therefore the effective dielectric constant of substrate is diminished to surrounding gradually by the centre, middle effective dielectric constant is maximum, thereby the refractive index of substrate diminishes to surrounding gradually from the centre, the refractive index of mid portion is maximum.

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, the pattern of artificial micro-structural can be two dimension, it can be also three-dimensional structure, " work " font (as shown in Fig. 5 A) that is not limited to use in this embodiment, can be the derived structure of " work " font, it can be the alabastrine derived structure shown in the orthogonal flakes in each limit in three dimensions shown in Fig. 5 B and Fig. 5 C and Fig. 5 D, it can be also other geometry, wherein different artificial micro-structurals can be that pattern is identical, but its design size is different, can be also that pattern and design size are all not identical.The quantity that consists of the substrate of super 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 super material panel.

Another embodiment of a kind of super material antenna of the present invention as shown in Figure 4, this antenna comprises: five oscillators 10 ', super material film layer 20 ' and reflector 30 ', described five oscillators 10 ' be arranged in side by side reflector 30 ', described super material film layer 20 ' and reflector 30 ' one of formation closed cavity, wherein, super material film layer 20 ' the be super material film layer 20 in five the first embodiment composition of arranging side by side.

Five oscillators 10 ' launch sphere electromagnetic wave major part directly to converge and be converted to plane electromagnetic wave by super material film layer 20 ' refraction, then radiate, converge and be converted to plane electromagnetic wave, radiate at last by super material film layer 20 ' refraction after all the other small part electromagnetic waves process reflector 30 ' reflection gains.

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

This present invention surpasses the refraction index profile situation of material film layer inside by change in sum, makes the half-power bandwidth of Antenna Far Field reduce, and then has promoted the distance that antenna is propagated, and has also increased the front and back ratio of antenna simultaneously.

Above-described embodiment is the better execution mode of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other any do not run counter to change, the modification done under Spirit Essence of the present invention and principle, substitutes, combination, simplify; all should be the substitute mode of equivalence, within being included in protection scope of the present invention.

Claims (9)

1. super material antenna, described antenna comprises an oscillator, for generation of electromagnetic wave; One surpass the material film layer, after being used for the electromagnetic wave that described oscillator produces is converged and to external radiation; It is characterized in that, described super material film layer is comprised of a plurality of super sheet of material, wherein, super sheet of material near described oscillator is the first to surpass sheet of material, the described refractive index rounded distribution take its center as the center of circle that the first surpasses sheet of material the first surpasses the refraction index profile of sheet of material along with Changing Pattern such as the following formula of radius r:

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

N in formula _maxExpression the first surpasses largest refractive index value in sheet of material, and d represents the first to surpass the thickness of sheet of material, and s represents that described 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,

Described antenna also comprises a reflector, and the part reflection of electromagnetic wave that is used for oscillator is produced is in super material film layer, and described reflector is a uncovered cavity and the formation closed cavity that is connected with super material film layer, and described oscillator is positioned at reflector.

2. a kind of super material antenna according to claim 1, is characterized in that, described reflector is electric conductor.

3. a kind of super material antenna according to claim 1, is characterized in that, the described 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 described substrate.

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

5. a kind of super material antenna according to claim 3, is characterized in that, described artificial micro-structural is for to be comprised of at least one one metal wire planar structure or the stereochemical structure that electromagnetic field is had response.

6. a kind of super material antenna according to claim 5, is characterized in that, described wire is copper wire or filamentary silver.

7. a kind of super material antenna according to claim 6, is characterized in that, described wire is attached on substrate by etching, plating, brill quarter, photoetching, electronics is carved or ion is carved method.

8. a kind of super material antenna according to claim 3, is characterized in that, described artificial micro-structural is " work " font or flakes.

9. a kind of super material antenna according to claim 3, is characterized in that, described substrate is made by ceramic material, epoxy resin, polytetrafluoroethylene, FR-4 composite material or F4B composite material.

Images