Background technology
Along with the development and progress of Electronics Science and Technology, more and more higher requirement is proposed to the antenna terminal played a crucial role in communication system, as required, antenna should have broadband or frequency reconfigurable performance, there is directional diagram reconstructable characteristic again, the realization of these performances to minimizing antenna amount, reduce communication system volume, to reduce the aspect such as system complexity and communication system cost significant.For realizing above characteristic, can on an antenna or antenna array, by independently regulating the partial parameters of antenna, size, the structure of such as antenna or give the additional high impedance surface of antenna etc., achieve the controlled of frequency and radiation direction.
Change antenna resonance length or its reactance value are the two kinds of major ways realizing antenna frequencies reconstruction property at present.Such as utilize the "on" and "off" two states of switch element, change antenna structure, obtain the physical dimension that different resonance frequencys is corresponding, realize the adjustment to operating frequency, or on the path, surface current place of antenna loaded switches, along with the break-make of switch, original antenna current paths will be switched on or block, thus obtains frequency reconfigurable antenna.Utilize the control of some method realization to antenna reactance value in addition, the such as reactance component such as loading capacitance, resistance, can obtain the restructural characteristic of frequency equally.Although the frequency that these methods can realize antenna is controlled, is merely able to increase less several operating frequency for antenna or is the very narrow available frequency band of antenna increase, to its frequency not being accomplished continuous print regulates and controls.
The main feature of directional diagram reconstructable aerial is under the condition keeping operating frequency constant, realizes the scanning to antenna greatest irradiation direction.At present, the directional diagram reconstructable aerial specific implementation form reported in document has following several: the mode adopting multiple feedback point feed, is changed the antenna pattern of antenna by the phase place of adjustment antenna difference feedback point; Utilize switch or reactance adjustable device, be carried in the parasitic element of the main radiating element periphery similar with yagi arrary, obtain different antenna patterns with this; Change aerial radiation shape with various switching component, regulate the radiation direction of antenna; The element that the reactance value such as loaded switches or variable capacitance is adjustable, regulates antenna surface CURRENT DISTRIBUTION, obtains corresponding different directions figure; Make mechanically, such as motor etc., change or select antenna pattern, obtaining the antenna pattern corresponding to difform antenna.But these change methods of directional diagrams and all need additionally to increase unnecessary element and could realize, thus implement relative trouble.
Utility model content
Technical problem to be solved in the utility model is to provide a kind of reconfigurable antenna based on Graphene coating, and it has the reconfigurable feature of antenna broadband, frequency reconfigurable and/or antenna pattern.
For solving the problem, the utility model is achieved through the following technical solutions:
Based on the reconfigurable antenna of Graphene coating, comprise antenna body, this antenna body comprises ground plate and stands on the monopole on ground plate; Described antenna body also comprises a up/down perforation and further in the dielectric sleeve of hollow columnar, and dielectric sleeve is positioned at the top of ground plate and is placed in the periphery of monopole; Side surface-coated in the interior outer surface of dielectric sleeve has Graphene coating, and opposite side surface-coated has silicon coating; Above-mentioned Graphene coating is respectively connected with one end of external bias voltage with silicon coating, and the Graphene coating be connected with the positive pole of external bias voltage or there is certain gap between silicon coating and ground plate.
As improvement, described silicon coating by be longitudinally separated into multiple separate and insulation equal portions, each equal portions forms the silicon chip of a longitudinal extension; Each silicon chip is connected with one end of an external bias voltage, and the other end of all external bias voltages is all connected with Graphene coating.
As further improvement, the bearing of trend of each silicon chip is all parallel with the bearing of trend of monopole.
As improvement, described Graphene coating by be longitudinally separated into multiple separate and insulation equal portions, each equal portions forms the graphene film of a longitudinal extension; Each graphene film is connected with one end of an external bias voltage, and the other end of all external bias voltages is all connected with silicon coating.
As further improvement, the bearing of trend of each graphene film is all parallel with the bearing of trend of monopole.
As improvement, silicon coating by be longitudinally separated into multiple separate and insulation equal portions, each equal portions forms the silicon chip of a longitudinal extension; Meanwhile, Graphene coating by be longitudinally separated into multiple separate and insulation equal portions, each equal portions forms the graphene film of a longitudinal extension; The number of the number of the silicon chip of the side surface-coated of dielectric sleeve and the graphene film of opposite side surface-coated equal; Each silicon chip is connected with one end of an external bias voltage, and the other end of this external bias voltage is connected with corresponding graphene film.
In such scheme, described dielectric sleeve is cylinder or multi-faceted column.
In such scheme, the radius of dielectric sleeve equals 1/2 of monopole and Graphene coating coupling frequency corresponding wavelength.
In such scheme, the height of dielectric sleeve is equal to or greater than the height of monopole.
In such scheme, described dielectric sleeve is made up of dielectric substance.
Compared with prior art, the utility model has following features:
1, on antenna inherent structure, to the high impedance surface of Graphene coating in its outer race, make antenna and peripheral high impedance surface generation electromagnetic coupled, produce coupled resonance frequency, the coupled resonance frequency of new generation and the former resonance frequency of antenna form the resonance band based on Graphene coating antenna system, make Graphene coating antenna realize broadband or ultra broadband;
2, by regulating the applying bias voltage of Graphene to change Graphene distribution of impedance and resistance value, regulate the resonance frequency based on Graphene coating antenna system, realize frequency reconfigurable, and by regulating applying bias voltage to realize operating frequency of antenna and regulate and control continuously, overcome frequency reconfigurable antenna in the past to can not the shortcoming of continuous tuning in the regulation and control of frequency.
3, Graphene is used as the high impedance surface of antenna, director or the reflector of antenna can be served as when small value is got in its impedance, do not need the graphene film of mobile different resistance value, the radiation direction of antenna just can be made to change, and then realize the directional diagram reconstructable of antenna.
4, Graphene has higher carrier density and good field effect characteristic, causes it to have special electrical property, makes the reconfigurable antenna based on Graphene have the advantages such as loss is little, efficiency is high, conductivity is adjustable.
5, can facilitate and reach antenna broadband, frequency reconfigurable and antenna pattern restructural easily, there is very strong practicality, be widely used in microwave frequency band, Terahertz frequency range, infrared and light wave frequency range.
Embodiment
Embodiment 1:
Based on a reconfigurable antenna for Graphene coating, comprise antenna body, as shown in Figure 1, this antenna body comprises ground plate 1 and stands on monopole 5 antenna model that the monopole 5 on ground plate 1 forms its structure.Above-mentioned ground plate 1 and monopole 5 are made by the metal that the electric conductivities such as gold, silver, aluminium, copper or iron are high.The structure of ground plate 1 and monopole 5 is same as the prior art or close.In order to improve the bandwidth of antenna, described antenna body comprises a up/down perforation and further in the dielectric sleeve 3 of hollow columnar.Described dielectric sleeve 3 is made up of silicon dioxide, alundum (Al2O3), GaAs, FR4 or other dielectric substances.Its shape can be cylinder or multi-faceted column.This dielectric sleeve 3 is positioned at the top of ground plate 1 and is placed in the periphery of monopole 5, and namely monopole 5 is placed in sleeve.Dielectric sleeve 3 is coated with Graphene coating 2 and silicon coating 4, and Graphene coating 2 and silicon coating 4 spaced.Concrete coating method has the following two kinds, and a kind of is at the graphene coated coating 2 of the inner surface of dielectric sleeve 3, outer surface silicon-coating coating 4; Another kind is at the graphene coated coating 2 of the outer surface of dielectric sleeve 3, inner surface silicon-coating coating 4.Above-mentioned Graphene coating 2 is respectively connected with one end of external bias voltage with silicon coating 4, and the Graphene coating 2 be connected with the positive pole of external bias voltage or there is certain gap between silicon coating 4 and ground plate 1.When the positive pole of Graphene coating 2 with external bias voltage is connected, when silicon coating 4 is connected with the negative pole of external bias voltage, between Graphene coating 2 and ground plate 1, there is certain gap; When the negative pole of Graphene coating 2 with external bias voltage is connected, when silicon coating 4 is connected with the positive pole of external bias voltage, between silicon coating 4 and ground plate 1, there is certain gap.
When the size of the antenna body of said structure changes, its resonance frequency domain also changes, and the frequency of antenna (microwave frequency band, Terahertz frequency range, infrared and light wave frequency range) can be realized in very wide band limits.By changing dielectric sleeve 3 and the Graphene coating 2 on surface thereof and the height of silicon coating 4 and radius, the coupling frequency of the Graphene coating 2 in monopole 5 and dielectric sleeve 3 can be changed, the operating frequency of antenna changes, and makes the frequency characteristic of antenna (microwave frequency band, Terahertz frequency range, infrared and light wave frequency range) can realize in very wide frequency range further.In the utility model, the radius of dielectric sleeve 3 approximates monopole 5 and 1/2 of Graphene coating 2 coupling frequency corresponding wavelength.The height of dielectric sleeve 3 approximates or is greater than the height of monopole 5.Strictly speaking, the radius of above-mentioned dielectric sleeve 3 is the radius of the mid-depth of dielectric sleeve 3, and when its thickness of dielectric sleeve 3 is less, the radius of its dielectric sleeve 3 also can be considered as inside radius or the outer radius of dielectric sleeve 3.
In order to ensure the loading reliability of external bias voltage, the Graphene coating 2 be connected with the positive pole of external bias voltage or silicon coating 4 can not directly and ground plate 1 conducting, that is: when the positive pole of Graphene coating 2 with external bias voltage is connected, when silicon coating 4 is connected with the negative pole of external bias voltage, between Graphene coating 2 and ground plate 1, there is certain gap; When the negative pole of Graphene coating 2 with external bias voltage is connected, when silicon coating 4 is connected with the positive pole of external bias voltage, between silicon coating 4 and ground plate 1, there is certain gap.
Example is connected to below with Graphene coating 2 and the positive pole of external bias voltage, the specific implementation that there is certain gap between Graphene coating 2 and ground plate 1 is described: a kind of mode is, the bottom of dielectric sleeve 3 is allowed directly to be fixed on ground plate 1, Graphene coating 2 can not be coated to least significant end and ground plate 1 connecting place on dielectric sleeve 3 surface always, but leaves certain gap when applying between Graphene coating 2 and ground plate 1.A kind of mode is, dielectric sleeve 3 is allowed to be hung on the top of ground plate 1, now leave certain gap between the bottom of dielectric sleeve 3 and ground plate 1, even if Graphene coating 2 is coated to the lowermost end on dielectric sleeve 3 surface like this, between Graphene coating 2 and ground plate 1, still certain gap can be there is.When silicon coating 4 is connected with the positive pole of external bias voltage, there is the specific implementation that there is certain gap between the specific implementation in certain gap and above-mentioned Graphene coating 2 and ground plate 1 between silicon coating 4 with ground plate 1 and duplicate mutually.
Because Graphene has unique two-dimension plane structure and conductivity and electric tunable characteristic.Go out the relation between the parameter such as Graphene conductivity and frequency, chemical potential, applied bias electric field, temperature, scattered power according to kubo equations, and draw the relation of graphenic surface impedance and applying bias.Thus, the surface resistance value of Graphene is regulated by applying bias macroscopic view.External bias voltage U is added by giving silicon coating 4 and Graphene coating 2, by the bias voltage U regulating Graphene additional, the surface impedance of Graphene changes, now coupling frequency equally also can change, the bandwidth of antenna can be made to widen, thus the contour performance of frequency ultra broadband characteristic of antenna can be realized.
Embodiment 2:
The another kind of reconfigurable antenna based on Graphene coating, comprise antenna body, its structure as shown in Figure 2.The structure of this antenna body is substantially identical with the antenna of embodiment 1, and its difference is, the Graphene coating 2 in embodiment 1 and silicon coating 4 are all be coated in dielectric sleeve 3 in overall, and it can improve the bandwidth of antenna.And Graphene coating 2 in the present embodiment and/or silicon coating 4 are the modes of the interval coating adopted, it can make antenna have frequency or directional diagram reconstructable performance.Specifically, can following three kinds of modes:
Mode one: Graphene coating 2 interval coating method.Graphene coating 2 is longitudinally separated into the separate and equal portions of insulation of n, and each equal portions forms the graphene film of a longitudinal extension.The number n of the graphene film of the side surface-coated of dielectric sleeve 3 and the reconstruction parameter of antenna about: during as obtained reconfiguration frequency and the directional diagram of more refinement, then the number of graphene film needs more, otherwise then the number of graphene film needs less.The bearing of trend of each graphene film generally along longitudinal direction and extends, and also can slightly tilt.But in order to obtain better performance, the bearing of trend of described each graphene film is all parallel with the bearing of trend of monopole 5.Each graphene film is connected with one end of an external bias voltage, and the other end of all external bias voltages is all connected with silicon coating 4.
Mode two: silicon coating 4 interval coating method.Silicon coating 4 is longitudinally separated into the separate and equal portions of insulation of m, and each equal portions forms the silicon chip of a longitudinal extension.The number m of the silicon chip of the side surface-coated of dielectric sleeve 3 and the reconstruction parameter of antenna about: during as obtained reconfiguration frequency and the directional diagram of more refinement, then the number of silicon chip needs more, otherwise then the number of silicon chip needs less.The bearing of trend of each silicon chip generally along longitudinal direction and extends, and also can slightly tilt.But in order to obtain better performance, the bearing of trend of described each silicon chip is all parallel with the bearing of trend of monopole 5.Each silicon chip is connected with one end of an external bias voltage, and the other end of all external bias voltages is all connected with Graphene coating 2.
Mode three: silicon coating 4 and Graphene coating 2 interval coating method simultaneously.Silicon coating 4 is longitudinally separated into the separate and equal portions of insulation of m, and each equal portions forms the silicon chip of a longitudinal extension; Meanwhile, Graphene coating 2 is longitudinally separated into the separate and equal portions of insulation of n, and each equal portions forms the graphene film of a longitudinal extension.The quantity of the number n of the number m of the silicon chip of the side surface-coated of dielectric sleeve 3 and the graphene film of opposite side surface-coated is equal, i.e. n=m.And the number m of silicon chip and the number n of graphene film and the reconstruction parameter of antenna about: during as obtained reconfiguration frequency and the directional diagram of more refinement, then the number of silicon chip and graphene film needs more, otherwise then the number of silicon chip and graphene film needs less.The bearing of trend of each silicon chip and graphene film generally along longitudinal direction and extends, and also can slightly tilt.But in order to obtain better performance, described each silicon chip is all parallel with the bearing of trend of monopole 5 with the bearing of trend of graphene film.The corresponding graphene film of each silicon chip, this silicon chip is connected with one end of an external bias voltage, and the other end of this external bias voltage is all connected with corresponding graphene film.
When Graphene coating 2 and/or silicon coating 4 are the modes of the interval coating adopted, the dielectric sleeve 3 of what it adopted is cylindrical shape, now only should be noted that and 2 mutually adjacent graphene films and/or silicon chip are separated, also the dielectric sleeve 3 of multi-faceted column shape can be adopted, and the face number of multi-faceted column is preferably identical with the number of black alkene sheet and/or silicon chip, now, every part of graphene film and/or silicon chip can be coated in the one side of this multi-faceted column just, and are spaced from each other.
Realize antenna and there is frequency or directional diagram reconstructable performance, need in use to control the external bias voltage of graphene film and/or silicon chip, and the surface resistance value making monopole 5 surrounding graphene film is different distribution.Wherein during low-voltage additional to graphene film, obtain high impedance; Otherwise, during to graphene film applying high voltage, obtain Low ESR.
Be divided into example with Graphene coating 2 by separation n below, the frequency of antenna and the pressuring method of directional diagram reconstruct be described in detail:
(1) frequency reconfiguration of antenna
Change n applying bias voltage (U1 to Un) of n part Graphene in Fig. 2, make graphene film be that high Low ESR intersection is uniformly distributed in a monopole 5 surrounding i.e. high impedance graphene film, the single cross-distribution of a Low ESR graphene film; Or two high impedance graphene films, the cross-distribution of two Low ESR graphene films; Or three high impedance graphene films, the cross-distribution of three Low ESR graphene films, goes down according to this, as long as aerial radiation direction keeps stable omnidirectional radiation.The high low-impedance intersection rule of graphene film is changed by changing every part of graphene film applying bias, the coupling frequency of the Graphene coating 2 in monopole 5 and dielectric sleeve 3 can be changed, achieve and the new coupling frequency produced is regulated, making antenna produce new operating frequency also can be adjusted, thus can realize the reconfigurable high-performance of antenna frequencies.
Regulate the size of the applying bias voltage of high Low ESR graphene film can change graphene film high impedance and low-impedance value, because the surface resistance value of Graphene changes, now coupling frequency equally also can change, the bandwidth of antenna can be made to widen, thus frequency reconfigurable or the contour performance of ultra broadband characteristic of antenna can be realized.
(2) the directional diagram reconstruct of antenna
In Fig. 2, add the bias voltage of U1 to Uk from the 1st part of graphene film to kth part graphene film respectively, add the bias voltage of Uk+1 to Un from kth+1 part of graphene film to n-th part of graphene film respectively.When the 1st part of graphene film adds identical bias voltage U1 to kth part graphene film, kth+1 part of graphene film adds identical bias voltage Uk+1 to n-th part of graphene film, 1 to kth part graphene film is made to get identical Low ESR, kth+1 gets identical high impedance to n-th part of graphene film, and now antenna is towards the place's radiation of high impedance Graphene.
By the distributing position regulating the applying bias of Graphene can change this k part Low ESR Graphene.Horizontal direction 360 degree changes the distributing position of Low ESR Graphene, because antenna is towards the radiation of high impedance direction, so now aerial radiation direction can in the horizontal direction in 360 degree of free adjustment, thus the reconfigurable high-performance in aerial radiation direction can be realized.
On aforementioned base, changing the number k of Low ESR Graphene by changing applying bias, the radiation subtended angle in antenna horizontal direction can be changed.