WO2021047245A1 - Radiation and scattering integrated information metamaterial surface and application thereof - Google Patents

Abstract

Disclosed is a radiation and scattering integrated information metamaterial surface. The information metamaterial surface is composed of periodically or non-periodically arranged artificial electromagnetic structural units, and has both the capability of regulating a radiated electromagnetic field/wave and the capability of regulating a scattered electromagnetic field/wave; each of the units constituting the information metamaterial surface at least has a 1-bit unit symbol; and the information metamaterial surface can be regulated within at least one electromagnetic physical domain. The information metamaterial surface solves the problem of a traditional metasurface whereby same is limited to only being applied to either the field of scattering or the field of radiation, and also has the capability of regulating electromagnetic waves in a multidimensional electromagnetic physical space with dimensions of time, space, frequency, polarization, etc. in real time, that is, same has a more powerful comprehensive regulation capability, and has broad application prospects in high-performance antennas, smart antennas, new-system radars, new-system communication systems, reduction of radar scattering cross sections, etc.

Description

A kind of radiation and scattering integrated information metamaterial surface and its application Technical field

The invention belongs to the technical field of a new type of artificial electromagnetic material surface, and in particular relates to a superstructure material surface with integrated information of radiation and scattering and its application.

Background technique

Metamaterials refer to artificial composite structures formed by units with sub-wavelength scales in a certain macroscopic arrangement (periodic or non-periodic). Since its basic unit and arrangement can be designed arbitrarily, it can break through the limitation of traditional materials that are difficult to accurately manipulate at the atomic or molecular level, construct ultra-conventional media parameters that cannot be achieved by traditional materials and traditional technologies, and then perform efficient and flexible control of electromagnetic waves. , To achieve a series of novel physical characteristics and applications. In the past two decades, metamaterials have been the international frontier in the field of physics and information. Based on the theory of equivalent media and guided by methods such as transform optics, new types of electromagnetic structure designs have continuously emerged, such as electromagnetic cloaks, invisible carpets, and perfection. Absorbers, electromagnetic black holes, etc., have attracted great attention from scientists and government organizations all over the world.

In the past two decades, metamaterials have been centered on equivalent media, but it is difficult for metamaterials based on equivalent media to manipulate electromagnetic waves in real time. From the perspective of circuits, metamaterials with continuous media parameters can be called analog metamaterials. In order to realize the "digital version" of metamaterials, Chinese scholars and the Engheta research group of the University of Pennsylvania in the United States independently proposed the concept of digital metamaterials. Engheta et al. proposed a method of constructing "metastructure material bytes" through spatially mixed "digital metamaterial bits" to achieve the required media parameters (Nature Materials, published online on September 14, 2014), among which "digital metamaterials" “Metamaterial position” is composed of material particles with different media parameters (such as positive and negative permittivity). Therefore, the core of Engheta’s work is to describe the equivalent medium by means of digital bits, which is still an equivalent medium superstructure. The category of materials. Due to the complexity of the actual operation, Engheta's work has not been experimentally verified so far. At the same time, Cui Tiejun and others creatively studied metamaterials from the perspective of information science, abandoning the representation method of equivalent media, and proposed a new idea of using digital codes to represent metamaterials, that is, information metamaterials. By changing the digital code The spatial arrangement of the units to control electromagnetic waves (Light: Science & Applications, formally accepted on September 9, 2014, published online on October 24, 2014). This idea was not only confirmed by experiments, but also opened up a new field, opening up a new direction for the development of metamaterial technology.

The information metamaterials involved in the present invention, or called digital electromagnetic metamaterials, electromagnetic coding metamaterials, can digitize electromagnetic analog signals and intelligently adjust the electromagnetic information characteristics of the materials in real time to adapt to or change the surrounding electromagnetic environment. One of the important features of the ability to control electromagnetic waves in real-time in multi-dimensional electromagnetic physical space such as time-space-frequency-polarization is the ability to directly process digitally encoded information. For example, 1-bit information metamaterials use the unit symbols of "0" and "1" to represent the phase response of 0 and π respectively, and then arrange the unit symbols of "0" and "1" according to a certain rule. The meta-material surface (or meta-surface, meta-surface) is formed to realize the required design function; and the 2-bit information meta-material consists of "00", "01", "10" and "11", etc. Unit symbols are used to represent the phase response of 0, π/2, π, and 3π/2, etc., so as to arrange the unit to form a meta-surface with a specific function; and so on, multi-bit unit symbols use phase difference A limited number of electromagnetic metamaterial unit forms that remain basically stable are arranged according to a certain coding law and have 2 ^N state characteristics, where N represents the number of bits, forming a metasurface with required functions. The multi-bit metasurface has the same digital design advantages as the 1-bit metasurface, and has more coding combinations, so the control of electromagnetic waves is more free, the functions that can be realized are more abundant, and the control effect is better.

Summary of the invention

Purpose of the invention: In view of the above problems, the present invention proposes an information metamaterial surface with divergence integration, which solves the limitation of traditional metasurfaces that are only used in the field of scattering or radiation, and has the time to electromagnetic waves. -Space-frequency-polarization and other multi-dimensional electromagnetic physical space real-time control capabilities.

Technical solution: In order to achieve the purpose of the present invention, the technical solution adopted by the present invention is: a surface of an information metamaterial integrated with radiation and scattering, and the surface of the information metamaterial is composed of periodic or aperiodic electromagnetic structures arranged Unit composition

The electromagnetic structure unit has an N-bit unit symbol, and the unit can achieve 2 ^N phase-frequency response states with a stable phase difference to the electromagnetic field/wave, and N is greater than or equal to 1;

The surface of the information metamaterial has both the ability of radiating electromagnetic field/wave regulation and scattering electromagnetic field/wave regulation, and the surface of the information metastructure material can be controlled by electromagnetic field/wave in at least one electromagnetic physical domain.

Further, the electromagnetic structure unit can perform phase encoding, or amplitude-phase encoding, or time-space-space encoding distributed arrangement to realize electromagnetic functions in at least one electromagnetic physical domain.

Further, the electromagnetic structural unit is an active reconfigurable control unit.

Further, the electromagnetic structure unit can be composed of any one or more of PIN diodes, varactor diodes, FET tubes, MEMS devices, liquid crystals, graphenes, or ferroelectric substrates to radiate and scatter electromagnetic fields/ The wave is regulated.

Further, the surface of the information metamaterial can be adjusted/modulated in any one of physical domains of amplitude, phase, frequency, and polarization of the radiated and scattered electromagnetic fields/waves or comprehensively controlled/modulated at the same time by multiple physical domains, so as to achieve specific The electromagnetic function.

Further, the excitation mode of the surface radiation of the information metastructure material may be an air-fed mode illuminated by a primary feed source, a single-reflection air-fed mode, a multiple-reflection air-fed mode, an air-fed mode of transmission transmission, and an air-fed mode of single reflection. The line-fed method composed of the electrical network, the composite air-fed method with both transmission and reflection, and the composite air-fed method with both the air feed and the line feed.

In addition, the present invention also provides an array antenna whose front surface adopts any one of the above-mentioned integrated radiation and scattering information metamaterial surfaces.

In addition, the present invention also provides a radome, radome, or communication window electromagnetic cover. The surface of the radome, radome, or communication window electromagnetic cover adopts any one of the above-mentioned radiation and scattering integrated information metamaterials. .

In addition, the present invention also proposes a smart skin. The surface of the smart skin adopts any one of the above-mentioned integrated radiation and scattering information metamaterial surfaces.

In addition, the present invention also provides an electromagnetic control surface, which adopts any one of the above-mentioned radiation and scattering integrated information metamaterial surfaces.

Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

The integrated radiation and scattering information metamaterial surface proposed by the present invention, in addition to adjusting the electromagnetic information characteristics of the traditional metamaterial surface and the existing information metamaterial surface, to adjust the electromagnetic wave/field characteristics, and further solve the problem. The traditional metasurface is only applied to the limitation of the field of scattering or radiation. At the same time, it has the ability to control electromagnetic waves in time-space-frequency-polarization and other multi-dimensional electromagnetic physical space in real time, that is, it has more powerful comprehensive control Capabilities have broad application prospects in high-performance antennas, smart antennas, new systems of radars, new systems of communication systems, and reduction of radar cross-sections.

Description of the drawings

Figure 1 is an example of a typical 2-bit information metamaterial surface.

Figure 2 is a schematic diagram of the electromagnetic/wave regulation mechanism of a typical 2-bit information metamaterial surface, in which: a-c are examples of different codes periodically arranged; d-f respectively correspond to the beam effects of different regulation of the aforementioned codes.

Fig. 3 is an embodiment of the surface of a 1-bit information metamaterial integrated with radiation and scattered radiation and scattering, where: a is an embodiment of a typical 1-bit information metamaterial unit; b is an example of a 1-bit information metamaterial unit; An example of the surface of the radiation and scattered radiation and scattering integrated information metamaterial formed by the bit metastructure unit.

Figure 4 is an example of the radiation and scattered beam control effect on the surface of the above-mentioned 1-bit information metamaterial with integrated radiation, scattered radiation and scattering, where: a is the integrated 1-bit information metastructure with radiation, scattered radiation and scattering The mechanism of radiation control on the surface of the material is shown; bc is an example of the effect of radiation beam control realized by the periodic arrangement of different codes; d is the scattering control of the surface of the 1-bit information metamaterial with integrated radiation and scattered radiation and scattering Schematic of the mechanism; bc is an example of the effect of scattered beam regulation realized by periodically arranging different codes.

Figure 5 is an example of the surface of a 2-bit information metamaterial with integrated radiation, scattered radiation and scattering, where: a is an example of the structure of the surface of a 2-bit information metamaterial with integrated radiation, scattered radiation and scattering ; B is an embodiment of a typical line-fed 2-bit information meta-material unit, c is a schematic diagram of the intermediate layer of the embodiment unit shown in b, and d is a 2-bit information meta-structure integrating radiation and scattered radiation and scattering An example of the effect of scattering control on the surface of a material; ef is an example of the effect of radiation control on the surface of a 2-bit information metamaterial that integrates radiation, scattered radiation and scattering.

Figure 6 is an example of the surface of a 2-bit information metamaterial with integrated radiation, scattered radiation and scattering, where: a is an example of the structure of the surface of a 2-bit information metamaterial with integrated radiation, scattered radiation and scattering ; B is an embodiment of a unit on the surface of a 2-bit information metamaterial that integrates radiation and scattered radiation and scattering; c is the effect of scattering control on the surface of a 2-bit information metamaterial that integrates radiation, scattered radiation and scattering Example; d is the radiation mechanism of the surface of the 2-bit information metamaterial with the integration of radiation, scattered radiation and scattering; e is the example of the effect of radiation control on the surface of the 2-bit information metamaterial with the integration of radiation, scattered radiation and scattering .

detailed description

The technical scheme of the present invention will be further described in detail below in conjunction with the accompanying drawings:

Those skilled in the art can understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meanings as commonly understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and unless defined as here, they will not be used in idealized or overly formal meanings. Explanation.

In the present invention, a limited type of artificial electromagnetic metamaterial unit that maintains a substantially stable phase difference in a wider frequency band is used as the basic coding unit, and different coding combinations are designed to form an information metamaterial surface that can realize specific functions. As shown in Figure 1, it is an example of a typical information metamaterial surface composed of units of 2-bit information metamaterial. It is composed of N×N periodic grids, and each grid is composed of a superstructure representing the same code. It is composed of an array of material units, selecting a limited number of types (for example, 1, 2, 3, etc.) of the phase state represented by a specific electromagnetic unit as the basic code element, and realizing amplitude modulation by changing the physical size structure or the equivalent electromagnetic structure. The phase modulation function is to perform coding and arrangement according to a certain law, thereby controlling the electromagnetic wave to achieve the required function. The 2-bit symbol is represented by the unit symbols of "00", "01", "10" and "11" respectively representing the phase responses of 0, π/2, π, and 3π/2.

The following is an example shown in Figure 2 to illustrate the regulation mechanism of different encoding arrangements on electromagnetic fields/waves. Plane waves are used as the excitation source. A represents the surface of the information metamaterial represented by all "10" symbols, and b represents " The surface of the information metamaterial with 00" and "10" symbols arranged at intervals, c characterizes the surface of the information metamaterial with "00", "01"/"11", and "10" periodically arranged, while d, e , F respectively correspond to the scattered field pattern of the surface arrangement of a, b, and c. Through the arrangement and combination of different phase quantities, a single focused beam, four beams symmetrical about the normal line, and symmetrical and uniformly dispersed about the normal line can be formed. Multi-beams; in addition, the deflection of the beam at any angle, or even diffuse reflection, can be formed through different phase arrangements.

Furthermore, according to the principle of reciprocity and equivalence of electromagnetic fields, the radiation field can be compared with the scattered field, except that the excitation source is different, but the corresponding electromagnetic field wave mechanism and the boundary conditions of the open domain are the same, so the information superstructure The ability of the surface of the material to control electromagnetic fields/waves can be characterized by the integration of radiation and scattered radiation and scattering. On the basis of the surface of the information metamaterial, the corresponding excitation source can be used to realize the control of one or more domains.

In the following, specific examples of the surface of the radiation and scattering integrated information metamaterial are further described in combination with specific application forms.

As shown in Figure 3a, a typical 1-bit information meta-material unit 31 is composed of a polygonal metal patch or metal patch pair structure 301, a PIN diode 302, a dielectric substrate 303, a reference ground 304, and a DC bias line 305. The unit constitutes an artificial electromagnetic meta-material unit; the metal patch pair structure 301 is on the upper surface of the dielectric substrate 303, the PIN diode 302 is surface-mounted on the metal patch pair structure 301, and the metal patch pair is bridged. The reference ground 304 is at On the lower surface of the dielectric substrate 303, the DC bias line 305 passes through the reference ground 304 and is connected to the metal patch structure 301 to provide the required bias DC for the PIN diode 302; the metamaterial unit 31 is controlled by the working state of the diode 302 It characterizes the two encoding states of "0" and "1". For example, the state is 0 when it is on and the state is 1 when it is off, respectively, indicating that the reflection phase difference is π in the working frequency band.

As shown in Fig. 3b, the M×N information metamaterial surfaces 32 that are repeatedly and periodically arranged by the 1-bit information metamaterial unit 31, plus the primary excitation feed 33, form a 1-bit information metamaterial unit 31. Reflective application form of the surface of the information metamaterial with the integration of radiation and scattered radiation and scattering. The surface of the information meta-material is connected to the corresponding drive circuit 34 through one or more groups of plugs or cables, and the drive circuit 34 is also connected to the control circuit 35 through another group or groups of plugs or cables. Specific regulatory functions. Among them, the driving circuit 34 includes an enable chip 306 that drives the diode 302 to work, and an operational amplifier chip 307. Each driving channel is connected to each diode 302 on the unit 31; and the control circuit 35 can be composed of one or several logic numbers. Chips, such as CPLD, FPGA, or DSP signal processing chips, or ARM, RISC-Ⅴ and single-chip microcomputer chips, etc., each I/O pin or enable pin of the control chip is connected to each drive channel, thereby forming the whole The unit control mode of the surface 32 of the information metamaterial.

Each control channel on the control circuit 35 corresponds to one or a group of enabling chips 306 and/or operational amplifier chips 307, and each enabling chip 306 and/or operational amplifier chip 307 corresponds to one on the surface 32 of the information metamaterial Or a set of PIN diodes 302. The information meta-material surface 32, the driving circuit 34, and the control circuit 35 can be used to connect the signals in the form of sockets or high-speed buses, etc., which can be implemented as a whole through a multi-layer laminated PCB process.

As shown in Fig. 4a, when the surface of the information metastructure material exhibits radiation characteristics, the feed source 43 acts as a primary excitation and irradiates the surface 42 of the information metastructure material to reflect the electromagnetic field to form a focused beam 44 to achieve electromagnetic wave signal transmission; According to the principle of Yi, the process of signal reception is the opposite of the process of signal transmission. Then, for the reflective M×N information metastructure material surface 42 arranged repeatedly and periodically, the information metamaterial unit 41 on the information metamaterial surface 42 is coded, and the unit 31 on the surface 32 is in accordance with different " The 0" and "1" symbols can be arranged to form different beams, and the pattern expression of the beam 44 is:

among them,

Is the reflected electric field pattern of the information metamaterial unit 41, θ and

The azimuth angles in the space under the spherical coordinate system, f _F (θ) is the electric field pattern of the feed 43, θ _fmn is the line connecting the feed to the center of the array and the feed to the (m, n)th metamaterial unit 41 is the angle of the line, k is the free space wave number,

Is the position vector of the (m, n)th metamaterial unit 41,

Is the position vector of feed 43,

Is the unit direction vector, θ _emn is the angle between the frontal normal and the line connecting the feed to the (m, n)th metamaterial unit 41,

Is the phase value corresponding to the code of the (m, n)th metamaterial unit 41, that is, for a 1-bit symbol, the "0" symbol represents the 0 discrete phase value, and the "1" symbol represents the π discrete phase value , From the point of view of the signal transmission process, through the feed 43 according to the position vector

Irradiate on the surface 42 of the information metamaterial to form a direction vector

Reflected beam; the process of signal reception is reciprocal. As shown in Figure 4b and Figure 4c, the phase value in the above expression is

That is, the arrangement of the symbols can realize the beams in the spatial angle (30°, 315°) direction and (45°, 135°) direction under the spherical coordinate system. Without loss of generality, by comparing the information on the surface 42 of the metamaterial The information metastructure material unit 41 is encoded and arranged, which can realize 0°≤θ≤90°,

Any spatially-directed beam, that is, the scanning of the beam direction is realized.

Furthermore, as shown in Fig. 4d, when the information metamaterial surface 42 exhibits scattering characteristics, the external excitation is a plane wave 45 irradiated on the information metamaterial surface 42 from a distance, and then a scattering field is formed by the information metamaterial surface 42 /Beam 47. For the M×N information metamaterial surfaces 42 that are repeatedly and periodically arranged, by encoding the information metamaterial units 41 on the information metamaterial surface 42, beams with different directions or different shapes can be realized The beam pattern of beam 47 is expressed as:

among them,

Is the pattern of the scattered electric field of the information metamaterial unit 41, θ and

Respectively the spatial azimuth angle in the spherical coordinate system, d is the periodic interval of the information meta-material unit 41,

Is the scattering phase value corresponding to the code of the (m, n)th metamaterial unit 41, that is, for a 1-bit symbol, the "0" symbol represents the 0 discrete phase value, and the "1" symbol represents the π discrete phase value. As shown in Figure 4e and Figure 4f, the phase value in the above expression is

That is, the arrangement of the symbols. For example, the phase encoding corresponding to Figure 4e is arranged according to a diagonal gradient, and the phase encoding corresponding to Figure 4f is arranged at intervals of "0" and "1" unit symbol rows and columns, so that specific bifurcation directions can be realized The beam deflection and the diffuse reflection beam with uniform energy dispersion, without loss of generality, can achieve specific beamforming characteristics by encoding and arranging the information metamaterial units 41 on the information metamaterial surface 42. In summary, for the same information meta-material surface 42, it is characterized by the integration of radiation and scattered radiation and scattering from the hardware. By arranging the codes of the information meta-material unit 41, it can pass through different positions. Unit 41 reconstructs the state of its active devices to realize real-time coding, such as the on and off of PIN diodes or FET tubes, the on and off of MEMS switches, the different capacitance values of varactor diodes, etc., and the artificial electromagnetic structure shows different performance The state of the amplitude and phase response to form different codes to achieve specific beams of radiation or scattering. Furthermore, through the continuous voltage control of the variable capacitance diode, it can even form a continuously adjustable phase state and form a continuously variable analog symbol, making the regulation of electromagnetic waves/fields more precise.

Without loss of generality, the encoding state change of the information metastructure material unit 31 can also be achieved by changing the characteristics of the dielectric substrate 303, for example, by changing the bias voltage value loaded on the liquid crystal, graphene, ferrite, or other materials. the equivalent relative permittivity ε _reff current media substrate to achieve equivalent or different states of relative permeability μ _reff of different equivalent relative permittivity ε _reff or equivalent relative permeability μ _reff exhibit Different phase response values, by selecting 2 or even 2 ^N equal phase states, or even continuously adjustable phase states, to achieve specific 1-bit or multi-bit unit symbols, or even continuously variable The simulation code element, and the information metamaterial surface formed by this unit, can control the electromagnetic wave/field in a manner similar to that shown in FIG. 3 above.

Next, in conjunction with FIG. 5, another specific embodiment of the surface of the integrated radiation and scattering information metamaterial is further described.

As shown in Figures 5a and 5b, it is an application form of a 2-bit line-fed information metamaterial surface 51, consisting of a typical 2-bit information metamaterial unit 52, feeder network 53, drive circuit 54, control circuit 55, each unit 52 is connected to the serial/parallel channels of the feed network 53 to form a channel of radio frequency signals; at the same time, each unit 52 and each drive channel on the drive circuit 54 pass through one or more sets of cables or The power strip is connected, and each drive channel on the drive circuit 54 is connected to the I/O pin or enable pin of the control chip on the control circuit 55 through another set of cables or power strips to form a drive control circuit.

Among them, the information meta-material unit 52 is composed of a PIN diode 521, a time delay/phase shift network 522, a radiation patch 523, a feeding point 524, a DC bias line 525, and a dielectric substrate 526; the unit 52 is a multilayer circuit structure, Fig. 5c is the middle layer of the unit 52 of the embodiment shown in Fig. 5b, namely: the feeding point 524 is located on the surface of the radiation patch 523, the radiation patch 523 is located on the top layer of the dielectric substrate 526, the DC bias line 525 and the radiation patch One side of 523 is connected, and the PIN diode 521 is provided with driving current through the feeding point 524; the feeding point 524 connects the radiation patch 523 on the top layer with the time delay/phase shift network 522 of the middle layer in the form of a via; The phase/phase shift network 522 is located in the middle layer of the dielectric substrate 526, and the internal transmission sections are connected through PIN diodes 521. At the same time, the center feed patch 527 is connected to the time delay/phase shift network 522 through the PIN diode 521; the feed network 53 is located in the medium On the bottom of the substrate 526, the center feed patch 527 is connected to the feed network 53 on the bottom of the dielectric substrate 526 through a central via hole.

When used as a scattering unit, similar to the aforementioned 1-bit information metamaterial unit 31, under the irradiation of a plane wave, through the combination of different PIN diodes 521 on the on-off delay line network 522, the induced current on the patch 523 is radiated Through the delay line network 522 of different codes, different reflection delays are formed, and unit symbols of "00", "01", "10" and "11" can be formed to represent 0, π/2, π and 3π/ respectively. 2. Scattering phase response. Therefore, the scattering field of the surface 51 of the 2-bit line-fed information metamaterial is consistent with equation (2).

When used as a radiating unit, the radio frequency signal is transmitted and excited through the feed network, and at the same time, through the combination of different specific PIN diodes 521 on and off, the radiation patch 522 can be stimulated by the feed of the delay network in different states. To form the radiation phase response of 0, π/2, π, and 3π/2. Furthermore, by adjusting the different bias currents or voltages loaded on the PIN diode 521, the equivalent internal resistance of the PIN diode can be adjusted equivalently to achieve further changes in the amplitude of the scattering/radiation field, thereby forming the amplitude distribution of each unit The weight of. Therefore, the expression of the radiation field on the surface 51 of the M×N line-fed 2-bit information metamaterials arranged repeatedly and periodically is:

among them,

Is the radiation electric field pattern of the information metastructure material unit 52, θ and

_{Respectively locating} the spatial azimuth angle in the spherical coordinate system, w mn is the amplitude of the (m, n)th metamaterial unit 52, and k is the free space wave number,

Is the position vector of the (m, n)th metamaterial unit 52,

Is the unit direction vector,

Is the phase value corresponding to the encoding of the (m, n)th metamaterial unit 52, that is, for the 2-bit encoding, the "00" symbol represents the 0 discrete phase value, and the "01" symbol represents the π/2 discrete phase Value, the "10" symbol represents the discrete phase value of π, and the symbol "11" represents the discrete phase value of 3π/2. It should be noted that the 2-bit concept here refers to the number of symbol bits corresponding to the phase response, and the significance of increasing the amplitude adjustment is to add more complex adjustment capabilities, which can further increase the amplitude of the beam on the basis of beamforming. modulation.

As shown in Fig. 5d, it is an example of the scattering characteristics of the surface 52 of the information metastructure material. Corresponding to a specific code arrangement, the equivalent internal resistance of the diode 521 can be changed by adjusting the different bias voltages loaded on the diode 521. Each unit 52 exhibits a different reflectivity value for the plane wave irradiated in the forward direction, and can exhibit a different degree of RCS reduction to the RCS in the forward reflection direction.

Furthermore, as shown in Fig. 5e and Fig. 5f, it is an example of the radiation characteristics exhibited by the surface 52 of the information metastructure. The encoding combination corresponding to a specific phase response, and the different bias voltage distributions form a spatial angle (30°, 0°) and spatial angle (50°, 90°) beam pattern, it can be seen that in the same encoding combination of phase response, the beams appear to be the same direction, but due to different offset voltage distributions, they appear to be different amplitude distributions. , It can be seen that the suppression effect of the beam sidelobe is consistent with the analysis and synthesis theory of the classic phased array.

It should be noted that the "line feed" method here refers to the use of transmission lines to form a feed network. The form of transmission lines is not limited to microstrip lines, strip lines, coplanar waveguides, waveguides, and artificial plasmons (SPP). ) Transmission lines, and other transmission lines.

Next, in conjunction with FIG. 6, another specific embodiment of the surface of the radiation and scattered radiation and the integrated information metamaterial of the scattering will be further described.

As shown in Figures 6a and 6b, it is an application form of a multi-bit information meta-material surface 61, which is composed of a typical multi-bit information meta-material unit 62, a drive and control circuit 63, etc., which are periodically arranged, plus The upper bottom plate 64 and the primary feed source 65 form a composite air-fed application form that integrates multi-bit radiation and scattered radiation and scattering. The drive and control circuit 63 is located under the bottom plate 64 through one or more sets of cables or The power strip is connected to the surface 61 of the meta-material, and the primary feed 65 is located on the upper surface of the bottom plate 64; the surface 61 of the meta-material and the bottom plate 64 can be connected and fixed by a structure such as a pillar or a casing.

Among them, the information meta-material unit 62 is composed of a varactor diode 621, a PIN diode 622, an open metal ring and a square patch to form a metal structure 623, a DC bias line 624, and a via 625. Among them, the square patch is located in the center of the open metal ring, the combined metal structure 623 is located on the upper surface of the dielectric substrate, and the varactor 621 bridges the open metal ring and the square patch of the combined metal structure 623 on both horizontal and vertical sides, and the PIN The diode 622 only needs to bridge the open metal ring of the combined metal structure 623 and the square patch on one side in the horizontal and vertical directions. The DC bias line 624 is in the center of the square patch and passes through the lower layer of the dielectric substrate and is finally connected to the drive and control circuit. 63 is connected to the flat cable or plug channel, and the via 625 is on the open metal ring and connected to the reference ground of the lower layer of the dielectric substrate, thereby forming a biased DC loop.

For the example of this unit 62, the varactor 621 characterizes different capacitance values under different bias voltages, so that the phase response of the metamaterial artificial structure 623 also changes correspondingly, because the voltage analog control is the digital control signal It is obtained through the conversion of N-bit digital/analog conversion chip, which is about to digitize the continuous analog quantity, so it constitutes the N-bit phase state, that is, 2 ^N types of symbols are formed, that is, the realization of multi-bit Unit coding.

On the other hand, by switching on and off different combinations of PIN diodes 622, different current feeding directions can be switched, because PIN diodes 622 have switching characteristics. The varactor diode 621 is short-circuited, so that the electrical adjustment in the short-circuited direction does not work, thereby realizing the selection and conversion of the electric field polarization of the information metamaterial surface 61.

When the information metamaterial surface 61 is irradiated by a plane wave, the regulation of its scattering beam is consistent with the above-mentioned scattering regulation mechanism and method. By changing different bias voltages, the varactor 621 can obtain different phase responses of the unit 62, then The information meta-material surface 61 under the different coding combinations of the unit 62 follows the above-mentioned scattering regulation mechanism in the same way to realize the deflection of the scattered beam, or diffuse reflection, etc.; further, as shown in Figure 6c, the PIN diode 622 can be The polarization control is adjusted by the on-off combination of, so that on the basis of beam deflection, the electric field polarization of the reflected beam 632 is orthogonal to the shape of the electric field polarization 631 of the incident plane wave.

As shown in Fig. 6d, it is the radiation working mechanism of a composite air-fed multi-bit radiation and scattering integrated surface application example. Preferably, the distance between the information metamaterial surface 61 and the bottom plate 64 is 0.45 to 0.55 times the wavelength, and The lower surface 641 of the information metastructure material surface 61 is a partially reflective surface, and its reflectivity is preferably 0.8 to 0.95. A resonant cavity with multiple reflections is formed between the information metastructure material surface 61 and the bottom plate 64, because the information metastructure material surface The lower surface 641 of 61 is a partially reflective surface, and part of the energy is transmitted to form an excitation with the cell 62 on the surface 61 of the information metastructure material, as a way of leaking waves to transmit and form a radiation beam. On this basis, as the control mechanism of the above-mentioned line-fed divergent integrated surface 51 is similar, by changing the bias voltage value on the varactor 621 on the unit 62, the phase of the information metamaterial surface 61 is distributed to Form the regulation of the beam.

Further, adjust the polarization control of the on-off combination of the PIN diode 622, as shown in FIG. 6e, changing the phase distribution encoding of the information metamaterial surface 61 not only can make the radiation beam point to different directions, but also achieve different For example, the polarization direction E _{1 of the} radiation beam 651 is parallel to the YOZ plane, and the polarization direction E _{2 of the} radiation beam 652 is perpendicular to the YOZ plane, and the beam directions of the two are opposite.

It should be noted that, for the application form of the composite air-fed integrated radiation and scattering, the form of the primary feed 65 is not limited to the form of the microstrip antenna in the above-mentioned embodiment, but can also be a planar dipole and its derivatives. Low-gain antennas such as form, waveguide opening, horn antenna, etc., or even an antenna array composed of the above-mentioned low-gain antennas with a limited number of elements.

The surface of the information metamaterial integrated with radiation and scattering can be adjusted in the physical dimensions of the time/frequency domain by changing or adjusting the coding sequence in addition to the above-mentioned spatial and polarization adjustment.

For the time/frequency domain adjustment of the scattering characteristics, a control device (such as FPGA, DSP, or single-chip microcomputer) is used to generate a time-varying signal to realize the time-varying reflection coefficient Γ(t). When the incident wave E _i (t) is incident on the surface, the reflected wave can be expressed as E _r (t) = E _i (t)·Γ(t). By selecting an appropriate time-domain coding sequence, the spectrum can be Regulation. The frequency spectrum of the time-domain reflected wave can be expressed by convolution as:

Among them, a ₀ is the 0th order Fourier series term, a _k is the kth order Fourier series term, and f _{0 is the} time domain modulation frequency and the repetition frequency of the time domain coding sequence. Therefore, the time-varying reflection coefficient can be used to control the time-domain characteristics of the reflected wave. For traditional devices or surfaces, because the reflection coefficient is time-invariant, there is only a ₀ term, and the following harmonic terms will not appear. For Chaogou surface material that / frequency modulated, time - space encoding, for example, arranged encoding time t ₀ is a unit symbol T ₁ time 0 unit symbols, t ₂ time for a unit symbol, Time t ₃ is 0 unit symbol...and so on, the time interval is 0.1ms, because the reflection coefficient is time-varying, there are high-order Fourier series terms, which can produce nonlinear characteristics to adjust the frequency spectrum. Since the surface of the information metamaterial adjusted in the time/frequency domain becomes a nonlinear device without the use of nonlinear materials, the amplitude and phase of each order of harmonics can be independently adjusted, that is, the control voltage combination can be used to Adjusting the amplitude of each order of the reflected wave and using the control signal delay to adjust the phase of each order of the reflected wave can not only realize the independent adjustment of the amplitude and phase of each order of the reflected wave, but also realize the simultaneous adjustment of multi-order harmonics. , It has great application value in the fields of communication, stealth and imaging.

It should be noted that the above-mentioned embodiments are merely illustrative, and the structure of the electromagnetic structural unit has various modifications, as long as the unit structure can realize the above-mentioned functions.

Without loss of generality, the above-mentioned integrated radiation and scattering information metamaterial surface can be used in the following applications.

The application field of the integrated radiation and scattering information metamaterial surface composed of the above features can constitute an array antenna with the integrated radiation and scattering information metamaterial. On the one hand, it is used as a phased array antenna in certain frequency bands or at certain times; on the other hand, it is used as a scattering adjustment surface in certain frequency bands or at certain times to reduce or enhance the RCS of the array antenna.

The application field of the information metamaterial surface integrated with radiation and scattering constituted by the above characteristics can constitute an electromagnetic enclosure such as a radome with integrated radiation and scattering information metamaterial, or a radome, or a communication window. On the one hand, it can be used as a "lens" in certain frequency bands or at certain times to achieve the effect of radiation enhancement; on the other hand, it can be used as a scattering adjustment surface in certain frequency bands or at certain times to reduce or enhance the shielding RCS of things.

The application field of the surface of the information metamaterial integrated with radiation and scattering constituted by the above-mentioned characteristics can constitute a smart skin with the integrated information metamaterial of radiation and scattering. On the one hand, it can be used as an electromagnetic sensor in certain frequency bands or at certain times to detect, process and transmit signals; on the other hand, it can be used as scattered beam regulation in certain frequency bands or at certain times, or to reduce or enhance the application of RCS.

The application field of the information metamaterial surface integrated with radiation and scattering constituted by the above characteristics can constitute an electromagnetic control surface of the information metamaterial integrated with radiation and scattering. On the one hand, it can be used as a relay node for communication transmission in certain frequency bands or at certain times, and forward the signal of a communication node at one end to expand the distance of network transmission or perform communication around obstacles; on the other hand, it can be used in certain frequency bands. Or some time is used as the application of scattered beam regulation to optimize the transmission network.

The above are only part of the embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (10)

1. An information metastructure material surface integrating radiation and scattering, characterized in that the information metamaterial surface is composed of periodic or aperiodically arranged electromagnetic structural units;

   The electromagnetic structure unit has an N-bit unit symbol, and the unit can achieve 2 ^N phase-frequency response states with a stable phase difference to the electromagnetic field/wave, and N is greater than or equal to 1;

   The surface of the information meta-material has both the functions of radiating electromagnetic field/wave regulation and scattering electromagnetic field/wave regulation, and the surface of the information meta-material can control electromagnetic fields/waves in at least one electromagnetic physical domain.
2. The surface of an information meta-material integrated with radiation and scattering according to claim 1, wherein the electromagnetic structure unit can be arranged in phase encoding, or amplitude-phase encoding, or time domain-spatial encoding distribution to achieve at least Electromagnetic function in an electromagnetic physical domain.
3. The surface of an information metamaterial with integrated radiation and scattering according to claim 1, wherein the electromagnetic structural unit is an active reconfigurable control unit.
4. The surface of an information meta-material integrated with radiation and scattering according to claim 1, wherein the electromagnetic structure unit can be composed of PIN diodes, varactor diodes, FET tubes, MEMS devices, liquid crystals, graphene Any one or more devices on the radiated and/or scattered electromagnetic fields/waves can be controlled by any one or more devices of the type or ferroelectric type substrate.
5. The surface of an information meta-material integrating radiation and scattering according to claim 2 or 3 or 4, characterized in that the surface of the information meta-material can perform amplitude, phase, and phase measurement of the radiation and scattering electromagnetic field or electromagnetic wave. Frequency and polarization are controlled or modulated in any physical domain, or multiple physical domains are comprehensively controlled or modulated at the same time to achieve specific electromagnetic functions.
6. The surface of an information metastructure integrated radiation and scattering according to claim 2 or 3 or 4, wherein the excitation method of the surface radiation of the information metamaterial can be an air feed irradiated by a primary feed source. Mode, single reflection air-fed mode, multiple-reflection air-fed mode, transmission transmission air-fed mode, line-fed mode composed of feeder network, composite air-fed mode with both transmission transmission and reflection, and air-fed mode with both transmission and reflection And line-fed composite air-fed mode.
7. An array antenna, characterized in that the front surface of the array antenna adopts the surface of the information metastructure integrated with radiation and scattering according to any one of claims 1-6.
8. A radome, radome, or communication window electromagnetic cover, characterized in that the surface of the radome, radome, or communication window electromagnetic cover adopts the integrated radiation and scattering information of any one of claims 1 to 6 Superstructure material surface.
9. A smart skin, characterized in that the surface of the smart skin adopts the surface of the information metastructure integrated with radiation and scattering according to any one of claims 1-6.
10. An electromagnetic control surface, characterized in that the electromagnetic control surface adopts the integrated radiation and scattering information metamaterial surface of any one of claims 1-6.

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