A broadband reflective metasurface and a control method thereof

Abstract

The application discloses a broadband reflective metasurface and a control method thereof. The broadband reflective metasurface comprises a plurality of broadband reflective units arranged in an array, which comprises a coupling layer, a modulation layer, a first ground layer, a filter layer, a second ground layer and a control line layer. The modulation layer comprises an adjustable patch layer and four diodes arranged on the adjustable patch layer. Each two diodes are used for X polarization direction and Y polarization direction respectively, and have different responses to different incident polarized waves under different control bias. The coupling layer is used for coupling with the adjustable patch layer after being excited by the incident polarized wave. The first ground layer is connected with the adjustable patch layer. The filter layer is connected with the adjustable patch layer and is used for filtering out harmonics. The second ground layer is connected with the filter layer. The control line layer is connected with the diodes and is used for controlling the working state of the diodes. The application realizes [0, pi] phase modulation of the incident polarized wave and cross-coupling modulation of the ultra-wideband response, and can control the circularly polarized incident wave.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic information technology, and in particular to a broadband reflective metasurface and a control method thereof. BACKGROUND

[0002] The broadband reflective metasurface is one of the most promising frontier technologies in the next generation of mobile communication systems, which can realize beamforming, vortex spatial multiplexing, spatial coding and other functions, thereby improving the communication capacity of the system, and even bringing about a revolution in the hardware system architecture. At present, the broadband reflective metasurface has a relatively clear application prospect in indoor and outdoor enhanced coverage, auxiliary multi-user communication and other aspects.

[0003] High speed, multi-user, large capacity and space-ground integration are the development trend of the next generation of communication technology. Under this trend, high frequency spectrum is gradually attracting more and more attention due to its large absolute available bandwidth. Larger available bandwidth can improve the communication capacity of the overall communication system, and more flexible allocation of frequency spectrum resources to adapt to the diversity of needs.

[0004] Under the background of space-ground integration, the common working frequency bands of satellite communication are Ku band (10.75GHz-18GHz) and Ka band (26.5-40GHz). The broadband reflective metasurface working in the Ku band and above accounts for a small proportion in the overall work, and the existing broadband reflective metasurface working at high frequency has a narrow working bandwidth, and generally only performs phase modulation on linearly polarized incident waves, and cannot perform phase modulation on circularly polarized incident waves.

[0005] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a broadband reflective metasurface and a control method thereof, to solve the problem that the existing broadband reflective metasurface has a narrow working bandwidth, and generally only performs phase modulation on linearly polarized incident waves, and cannot perform phase modulation on circularly polarized incident waves.

[0007] The technical scheme of the present application is as follows:

[0008] A broadband reflective metasurface, comprising a plurality of broadband reflective units arranged in an array, the broadband reflective unit comprising: a coupling layer, a modulation layer, a first ground layer, a filter layer, a second ground layer and a control line layer; wherein the modulation layer comprises an adjustable patch layer and four diodes arranged on the adjustable patch layer, and each two diodes act on the X polarization direction and the Y polarization direction respectively, and the diodes have different responses to different incident polarized waves under different control biases.

[0009] The coupling layer is arranged opposite to the adjustable patch, and is used for coupling with the adjustable patch after being excited by an incident polarized wave.

[0010] The first ground layer is connected with the adjustable patch layer.

[0011] The filter layer is connected with the adjustable patch layer, and is used for filtering out harmonics.

[0012] The second ground layer is connected with the filter layer.

[0013] The control line layer is connected with the diode, and is used for controlling the working state of the diode.

[0014] Further, the diode is a PIN diode, and the four PIN diodes have 16 states, including the following four types:

[0015] Two PIN diodes in a certain polarization direction are simultaneously subjected to positive bias, and are in a short-circuit state or an open-circuit state.

[0016] One of the two PIN diodes in a certain polarization direction is subjected to positive bias, and the other is subjected to negative bias, while the two PIN diodes in another polarization direction are both in a short-circuit state.

[0017] One of the PIN diodes in a certain polarization direction is subjected to positive bias, and the other is subjected to negative bias, while the two PIN diodes in another polarization direction are both in an open-circuit state.

[0018] Two adjacent PIN diodes are simultaneously subjected to positive bias or negative bias.

[0019] Further, the adjustable patch layer comprises a first dielectric plate, a square patch and a T-shaped patch.

[0020] The first dielectric plate is arranged on the first ground layer.

[0021] The square patch is arranged on the first dielectric plate, and the square patch is connected with the first ground layer through a grounding pin.

[0022] The T-shaped patch is arranged around the square patch, and the T-shaped patch is connected with the filter layer through a bias pin.

[0023] The positive pole of the PIN diode is connected with the T-shaped patch, and the negative pole of the PIN diode is connected with the square patch.

[0024] Further, the coupling layer comprises a second dielectric plate and a coupling patch, wherein

[0025] The second dielectric plate is arranged on the modulation layer.

[0026] The coupling patch is arranged on the second dielectric plate.

[0027] Further, the filter layer comprises a third dielectric plate, four filter inductors, and a zigzag microstrip line.

[0028] The filter inductors are arranged on the third dielectric plate.

[0029] The zigzag microstrip line is arranged on the third dielectric plate, connected with the filter inductors, and connected with the T-shaped patch through the biasing needle.

[0030] Further, the control line layer comprises a first control line layer and a second control line layer.

[0031] Two DC biasing control wires are arranged on the first control line layer and the second control line layer respectively, and connected with the PIN diode respectively; wherein the DC biasing control wires are connected with the PIN diode through DC control wire connecting needles.

[0032] Further, the broadband reflection unit further comprises a second ground layer and a fourth dielectric plate; wherein,

[0033] The second ground layer is arranged on the fourth dielectric plate; wherein the first control line layer is arranged on the third dielectric plate, and the second control line layer is arranged on the fourth dielectric plate.

[0034] Further, the broadband reflection unit further comprises a first adhesive plate and a second adhesive plate; wherein,

[0035] The first adhesive plate is connected between the first ground layer and the third dielectric plate.

[0036] The second adhesive plate is connected between the second ground layer and the fourth dielectric plate.

[0037] Further, the array mode on the broadband reflection metasurface is a 4*4 array, an 8*8 array, or a 16*16 array.

[0038] Based on the same inventive concept, the application further provides a control method of the broadband reflection metasurface, which comprises:

[0039] When the broadband reflection unit receives an incident polarized wave, the coupling layer and the adjustable patch layer are excited to be coupled with each other.

[0040] The working state of the diode is controlled to manipulate linearly polarized incident waves and circularly polarized incident waves.

[0041] The further arrangement of the present application is that the diode is a PIN diode, each wideband reflection unit is provided with 4 PIN diodes, and the 4 PIN diodes have 16 states; the step of controlling the working state of the PIN diode to manipulate linearly polarized incident waves and circularly polarized incident waves comprises:

[0042] When the wideband reflection unit works in the first to twelfth states, linearly polarized incident waves are manipulated;

[0043] When the wideband reflection unit works in the thirteenth to sixteenth states, circularly polarized incident waves are manipulated.

[0044] The further arrangement of the present application is that when the wideband reflection unit works in the first to twelfth states, the following three types of states are included:

[0045] When the wideband reflection unit works in the first to fourth states, two PIN diodes in a certain polarization direction are simultaneously subjected to positive bias, and are in a short-circuit state or an open-circuit state;

[0046] When the wideband reflection unit works in the fifth to eighth states, one of the two PIN diodes in a certain polarization direction is subjected to positive bias, and the other is subjected to negative bias, and the two PIN diodes in another polarization direction are both in a short-circuit state;

[0047] When the wideband reflection unit works in the ninth to twelfth states, one of the PIN diodes in a certain polarization direction is subjected to positive bias, and the other is subjected to negative bias, and the two PIN diodes in another polarization direction are both in an open-circuit state.

[0048] The further arrangement of the present application is that when the wideband reflection unit works in the thirteenth to sixteenth states, two adjacent PIN diodes are simultaneously subjected to positive bias or negative bias, the X polarization direction and the Y polarization direction are cross-coupled, the polarization of the incident polarized wave is converted, and the circularly polarized incident wave is manipulated.

[0049] This invention provides a broadband reflective metasurface and its control method. The broadband reflective metasurface includes several arrayed broadband reflective units. Each broadband reflective unit includes a coupling layer, a modulation layer, a first ground layer, a filtering layer, a second ground layer, and a control line layer. The modulation layer includes an adjustable patch layer and four diodes disposed on the adjustable patch layer, with each pair of diodes acting in the X-polarization direction and the Y-polarization direction, respectively. The diodes have different responses to different incident polarized waves under different control bias voltages. The coupling layer is disposed opposite to the adjustable patch and is used to couple with the adjustable patch after being excited by the incident polarized wave. The first ground layer is connected to the modulation layer. The filtering layer is connected to the modulation layer and is used to filter out harmonics. The second ground layer is connected to the filtering layer. The control line layer is connected to the diodes and is used to control the operating state of the diodes. This invention achieves an ultra-wideband response with [0, π] phase modulation and cross-coupling modulation by setting a coupling layer on the modulation layer. When an incident polarized wave is incident on the broadband reflective metasurface, the coupling layer couples with the modulation layer. By controlling the operating states of four diodes, ultra-wideband responses with [0, π] phase modulation and cross-coupling modulation of the incident polarized wave are realized. Furthermore, by controlling the operating states of the four diodes, the polarization deflection of the incident polarized wave can be achieved, thereby enabling manipulation of circularly polarized incident waves. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the structure of the broadband reflective metasurface in this invention.

[0052] Figure 2 This is a schematic diagram of the structure of the broadband reflection unit in this invention.

[0053] Figure 3 This is a top view of the broadband reflection unit in this invention.

[0054] Figure 4 This is a schematic diagram of the adjustable patch layer in this invention.

[0055] Figure 5 This is a side view of the broadband reflection unit in this invention.

[0056] Figure 6 This is a schematic diagram of the filter layer in this invention.

[0057] Figure 7is the coupling schematic diagram of the broadband reflection unit in the application.

[0058] Figure 8 is the response result diagram of linear polarization when the broadband reflection unit in the application works in State 3.

[0059] Figure 9 is the response result diagram of linear polarization when the broadband reflection unit in the application works in State 5.

[0060] Figure 10 is the response result diagram when the broadband reflection unit in the application works in State 9.

[0061] Figure 11 is the response result diagram when the broadband reflection unit in the application works in State 13.

[0062] Figure 12 is the diagram of four different phase reflection states when the broadband reflection unit in the application responds to linear polarization.

[0063] Figure 13 is the amplitude and phase response result diagram of the broadband reflection unit in the application working in State 3, State 5 and State 13 in the frequency band of 11.25-12.25 GHz.

[0064] Figure 14 is the flowchart of the array configuration of the required beam for single polarization realized by the GS algorithm in the application.

[0065] Figure 15 is the schematic diagram of the functions that can be realized by the broadband reflection metasurface in the application.

[0066] Figure 16 is the flowchart of the control method of the broadband reflection metasurface in the application.

[0067] In the drawings, 1 is a coupling layer; 11 is a second dielectric plate; 12 is a coupling patch; 2 is a modulation layer; 21 is a diode; 22 is a first dielectric plate; 23 is a square patch; 24 is a T-shaped patch; 3 is a first ground layer; 4 is a filter layer; 41 is a third dielectric plate; 42 is a filter inductor; 43 is a zigzag microstrip line; 5 is a second ground layer; 6 is a direct current bias control trace; 7 is a fourth dielectric plate; 8 is a first adhesive plate; 9 is a second adhesive plate; 10 is a grounding needle; 13 is a bias needle; 14 is a direct current control trace connecting needle. DETAILED DESCRIPTION

[0068] The present application provides a broadband reflective metasurface and a control method thereof. To make the purpose, technical solutions and effects of the present application clearer and more explicit, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0069] In the embodiments and the patent claims, unless the article is specifically limited, "one", "an", "said" and "the" can also include plural forms. If the description of the embodiments of the present application involves "first", "second", etc., the description of "first", "second", etc. is only for the purpose of description and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features.

[0070] It should be further understood that the phrase "comprising" used in the specification of the present application means that the features, integers, steps, operations, elements and / or components exist, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intermediate elements. In addition, "connection" or "coupling" used herein can include wireless connection or wireless coupling. The phrase "and / or" used herein includes all or any single unit and all combinations of the associated listed items.

[0071] Those skilled in the art can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as that generally understood by those skilled in the art to which the present application belongs. It should also be understood that terms such as those defined in a general dictionary should be understood as having meanings consistent with those in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as such.

[0072] In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0073] Please also refer to Figures 1 to 15 The present application provides a preferred embodiment of a broadband reflective metasurface.

[0074] As Figure 1As shown, the present application provides a broadband reflective metasurface, which comprises a plurality of broadband reflective units arranged in an array. In some embodiments, the array on the broadband reflective metasurface can be, but is not limited to, a 4*4 array, an 8*8 array or a 16*16 array, for example, an 8*8 array.

[0075] Please refer to Figures 1 to 3 In some embodiments, the broadband reflective unit comprises a coupling layer 1, a modulation layer 2, a first ground layer 3, a filter layer 4, a second ground layer 5 and a control line layer. The modulation layer 2 comprises an adjustable patch layer and four diodes 21 arranged on the adjustable patch layer, and each two diodes 21 act on the X polarization direction and the Y polarization direction respectively, and the diodes 21 have different responses to different incident polarized waves under different control biases; the coupling layer 1 is arranged opposite to the adjustable patch layer and is used to couple with the adjustable patch layer after being excited by the incident polarized wave; the first ground layer 3 is connected with the adjustable patch layer; the filter layer 4 is connected with the adjustable patch layer and is used to filter out harmonics; the second ground layer 5 is connected with the filter layer 4; and the control line layer is connected with the diodes 21 and is used to control the working state of the diodes 21.

[0076] Specifically, the diodes 21 can be PIN diodes or varactor diodes, and in the present application, the diodes 21 are PIN diodes, the control line layer is connected with the PIN diodes, and the control line layer can output an electrical signal to control the on-off state of the PIN diodes. Since each two PIN diodes act on the X polarization direction and the Y polarization direction respectively, and the PIN diodes have different responses to different incident polarized waves under different control biases, the structure of the broadband reflective unit and the broadband reflective metasurface can be changed by controlling the working state of the PIN diodes, so as to control the linearly polarized incident wave and the circularly polarized incident wave. The coupling layer 1 is arranged on the modulation layer 2, when there is an incident polarized wave, the coupling layer 1 and the adjustable patch layer will be excited and scattered, and at the same time, the coupling layer 1 and the adjustable patch layer will also be coupled with each other to achieve broadband characteristics. At this time, by controlling the working state of the four PIN diodes, the broadband response of [0, π] phase modulation of the incident polarized wave and the broadband response of cross-coupling modulation can be realized.

[0077] The first stratum 3 divides the wideband reflection unit into two parts, the coupling layer 1 and the modulation layer 2 above the first stratum 3 are the main body reflection structure, which is an alternating structure layer, and the filter layer 4 and the control line layer are direct current structure layers, the first stratum 3 can isolate the direct current layer from the alternating current layer, realize the independent work of the direct current layer and the alternating current layer, and avoid the interference of the direct current layer on the alternating current layer. In addition, the filter layer 4 is located below the first stratum 3 and does not affect the main body reflection structure of the upper layer, and the response of the wideband reflection unit is improved under the filtering effect of the filter layer 4, so that a wideband high-efficiency response can be finally obtained.

[0078] It can be seen that, by using the multi-layer architecture of the coupling layer 1, the modulation layer 2, the first stratum 3, the filter layer 4, the second stratum 5 and the control line layer, the isolation of the direct current layer and the alternating current layer of the wideband reflection metasurface overall structure is realized, and the influence of the direct current control line layer on the response of the alternating current layer can be effectively reduced. In addition, by arranging the coupling layer 1 on the modulation layer 2, when a polarized wave is incident on the wideband reflection metasurface, the coupling layer 1 and the modulation layer 2 are coupled, the working state of the four PIN diodes is controlled, the super wideband response of [0, π] phase modulation of the incident polarized wave and the super wideband response of cross-coupling modulation are realized. Furthermore, by controlling the working state of the four PIN diodes, the incident polarized wave is polarized and deflected, so that the circularly polarized incident wave can be controlled, the linearly polarized incident wave and the circularly polarized incident wave can be controlled, and beamforming can be realized.

[0079] Please refer to Figures 2 to 5 In a further embodiment of the embodiment, the adjustable patch layer comprises: a first dielectric plate 22, a square patch 23 and a T-shaped patch 24; the first dielectric plate 22 is arranged on the first stratum 3; the square patch 23 is arranged on the first dielectric plate 22, and the square patch 23 is connected with the first stratum 3 through a grounding needle 10; the T-shaped patch 24 is arranged with four and arranged around the square patch 23 respectively, and the T-shaped patch 24 is connected with the filter layer 4 through a bias needle 13; the positive electrode of the PIN diode is connected with the T-shaped patch 24, and the negative electrode of the PIN diode is connected with the square patch 23.

[0080] Specifically, the first dielectric plate 22 is located above the first stratum 3, and the first stratum 3 isolates the modulation layer 2 from the filter layer 4 and the control line layer. The square patch 23 is located at the center position of the first dielectric plate 22, and the square patch 23 and the first stratum 3 are provided with a through hole, and the square patch 23 is arranged in the square patch 23 and the first stratum 3 through the grounding needle 10 to realize grounding.

[0081] The number of the T-shaped patches 24 corresponds to the number of the PIN diodes, i.e. four T-shaped patches 24 are arranged on the four edges of the square patch 23, wherein the T-shaped patch 24, the first dielectric plate 22 and the first ground layer 3 are provided with a through hole, and the T-shaped patch 24 is connected with the filter layer 4 through the biasing pin 13 after sequentially penetrating the first dielectric plate 22 and the first ground layer 3. The PIN diode is integrated on the adjustable patch layer, wherein the positive electrode of the PIN diode is connected with one end of the T-shaped patch 24, and the negative electrode of the PIN diode is connected with the square patch 23. It can be seen that the four PIN diodes can act on the X-polarization direction and the Y-polarization direction respectively.

[0082] Referring to Figure 2 and Figure 5 In a further embodiment of the embodiment, the coupling layer 1 comprises: a second dielectric plate 11 and a coupling patch 12; wherein the second dielectric plate 11 is arranged on the modulation layer 2; and the coupling patch 12 is arranged on the second dielectric plate 11.

[0083] Specifically, the second dielectric plate 11 is located between the first dielectric plate 22 and the coupling patch 12, when an incident polarized wave is incident, the coupling patch 12 and the adjustable patch layer are excited to scatter, and the coupling patch 12 and the adjustable patch layer are coupled. In some embodiments, the shape of the coupling patch 12 can be, but is not limited to, a square, a cross, a Jerusalem cross, etc., for example, the coupling patch can be a square coupling patch.

[0084] Referring to Figure 2 and Figure 6 In a further embodiment of the embodiment, the filter layer 4 comprises: a third dielectric plate 41, four filter inductors 42 and a zigzag microstrip line 43; the filter inductor 42 is arranged on the third dielectric plate 41; the zigzag microstrip line 43 is arranged on the third dielectric plate 41 and connected with the filter inductor 42, and is connected with the T-shaped patch 24 through the biasing pin 13.

[0085] Specifically, the filter inductance 42 is a passive sector inductance, the number of the filter inductance 42 corresponds to the number of the PIN diode, that is, four filter inductances are arranged on the third dielectric plate 41, the filter inductance 42 is connected with the zigzag microstrip line 43, and the biasing pin 13 is connected with the zigzag microstrip line 43. When the incident polarized wave is incident on the wideband reflection unit, the adjustable patch layer is excited to induce a current, and part of the energy is guided away by the biasing pin 13. Since the filter inductance 42 is located between the first ground layer 3 and the second ground layer, on the one hand, the direct current layer of the lower two layers does not affect the main body reflection structure of the upper layer (that is, the structure above the first ground layer 3), so that the isolation of the direct current layer and the alternating current layer is realized, and on the other hand, the filtering effect of the filter inductance 42 can improve the wideband response of the wideband reflection unit.

[0086] Referring to Figure 2 and Figure 6 In a further embodiment of the embodiment, the wideband reflection unit further comprises: a second ground layer 5 and a fourth dielectric plate 7; wherein the second ground layer 5 is arranged on the fourth dielectric plate 7.

[0087] Referring to Figure 2 and Figure 6 Further, the control line layer comprises: a first control line layer and a second control line layer; two direct current biasing control wires 6 are arranged on the first control line layer and the second control line layer respectively, and are connected with the PIN diode respectively; wherein the direct current biasing control wire 6 is connected with the PIN diode through a direct current control wire connection pin 14.

[0088] Specifically, the first control line layer is arranged on the third dielectric plate 41, and the second control line layer is arranged on the fourth dielectric plate 7. In addition, the filter layer 4 is located between the first ground layer 3 and the second ground layer 5, and does not affect the main body reflection structure of the upper layer. The number of the direct current biasing control wire 6 corresponds to the number of the PIN diode, each direct current biasing control wire 6 is connected with a PIN diode through a direct current control wire connection pin 14, and controls the on-off state of the PIN diode.

[0089] Referring to Figure 2 and Figure 6 In a further embodiment of the embodiment, the wideband reflection unit further comprises: a first adhesive plate 8 and a second adhesive plate 9; wherein the first adhesive plate 8 is connected between the first ground layer 3 and the third dielectric plate 41; and the second adhesive plate 9 is connected between the second ground layer 5 and the fourth dielectric plate 7.

[0090] Specifically, the first adhesive plate 8 is connected between the first ground layer 3 and the third dielectric plate 41, and the second adhesive plate 9 is connected between the second ground layer 5 and the fourth dielectric plate 7, so as to bond the wideband reflection unit as a whole.

[0091] Wherein, the mutual coupling relationship of each layer structure of the wideband reflection unit is as shown in the figure, Figure 7 Figure 7 Wherein, TP represents the coupling patch 12, MS represents the tunable patch layer, GND represents the first ground layer 3 and the second ground layer 5, and Air represents air. It can be seen that the coupling patch 12, the tunable patch layer, the first ground layer 3, and the second ground layer 5 are directly coupled or coupled through air.

[0092] In a further embodiment of the embodiment, the four PIN diodes have 16 states, including the following four categories: two PIN diodes in a certain polarization direction are simultaneously applied with positive bias, in a short-circuit state or an open-circuit state; one of the two PIN diodes in a certain polarization direction is applied with positive bias, and the other is applied with negative bias, while the two PIN diodes in the other polarization direction are both in a short-circuit state; one of the PIN diodes in a certain polarization direction is applied with positive bias, and the other is applied with negative bias, while the two PIN diodes in the other polarization direction are both in an open-circuit state; the two adjacent PIN diodes are simultaneously applied with positive bias or negative bias.

[0093] Specifically, since the PIN diode has only two states (on or off), the control state of the wideband reflection unit and the number of embedded PIN diodes satisfy the relationship of 2 N N represents the number of PIN diodes integrated in the wideband reflection unit. In the present application, the number of PIN diodes is four, so that the PIN diodes have 16 states, and the control state of the wideband reflection unit is 16. The working state of the PIN diode is shown in Table 1:

[0094]

[0095]

[0096] When only considering the response of a single linearly polarized incident wave, the 16 states of the PIN diode can be divided into the following four categories:

[0097] 1. Two PIN diodes in a certain polarization direction are simultaneously applied with positive bias, i.e. State 1-4, in a short-circuit state or an open-circuit state, i.e. including the case of "same opening" and "same short" of any two switch diodes with the same polarization.

[0098] ​2. Two PIN diodes in one polarization direction are biased with one positive and one negative bias, while the two PIN diodes in the other polarization direction are shorted, i.e. State 5-8;

[0099] 3. One PIN diode in one polarization direction is biased with positive bias, one PIN diode in one polarization direction is biased with negative bias, while the two PIN diodes in the other polarization direction are open, i.e. State 9-12;

[0100] 4. Two adjacent PIN diodes are biased with positive bias or negative bias, i.e. State 13-16, for example, when two adjacent PIN diodes are biased with positive bias, i.e. shorted state, the other two PIN diodes are biased with negative bias, i.e. open state. When the wideband reflection unit works in the state State 13-16, the wideband reflection unit will deflect the polarization of the incident polarized wave, and the x-y polarization directions will appear cross-coupling, so that when the wideband reflection unit responds to the circularly polarized incident wave, it can convert the right-handed circular polarization (RCP) into left-handed circular polarization (LCP), i.e. RCP→LCP, and convert the left-handed circular polarization into right-handed circular polarization, i.e. LCP→RCP, thereby realizing the manipulation of the circularly polarized incident wave.

[0101] As shown in Table 1 above, the response of the wideband reflection unit to a certain linearly polarized incident wave only needs the response results of State 3, State 5, State 9 and State 13.

[0102] As shown in Table 1 above, the response of the wideband reflection unit to a certain linearly polarized incident wave only needs the response results of State 3, State 5, State 9 and State 13. Figure 8 Figure 8 Fig. 3 is a response result diagram of linear polarization when the wideband reflection unit works in State 3, wherein Figure 8 (a) is a reflection amplitude diagram, Figure 8 (b) is a reflection phase diagram, wherein R xx represents x-polarized reflection / x-polarized incident wave, R xy represents y-polarized reflection / x-polarized incident wave, R yx represents x-polarized reflection / y-polarized incident wave, and R yy represents y-polarized reflection / y-polarized incident wave. As shown in Figure 8 , in the frequency band of 10-15 GHz, the reflection amplitude of the wideband reflection unit is above 0.8, and the phase difference of the two orthogonal polarizations of the wideband reflection unit is 180°, which is close to the parallel state in the frequency band of 10-15 GHz, i.e. the wideband reflection unit works in the half-wave state, which can realize the wideband characteristic of the wideband half-wave characteristic.

[0103] Fig. 4 is a response result diagram of linear polarization when the wideband reflection unit works in State 5, wherein​Figure 9 Fig. 6 shows the response result diagram of the broadband reflection unit working in the state State 5, Figure 9 Fig. 7 shows the response result diagram of the broadband reflection unit working in the state State 5, Figure 9 (a) is a reflection amplitude diagram, Figure 9 (b) is a reflection phase diagram, and Figure 9 It can be seen that, in the 10-15 GHz frequency band, the amplitude of the broadband reflection unit is above 0.8, and the response of the X-polarization direction is the same as that of the state State 3, and the phase curve of the Y-polarization direction response changes.

[0104] Fig. 8 shows the response result diagram of the broadband reflection unit working in the state State 9, Figure 10 Fig. 9 shows the response result diagram of the broadband reflection unit working in the state State 9, Figure 10 (a) is a reflection amplitude diagram, Figure 10 (b) is a reflection phase diagram, and Figure 10 It can be seen that, in the 10-15 GHz frequency band, the amplitude of the broadband reflection unit is above 0.8, and the response of the Y-polarization direction is the same as that of the state State 3, and the phase curve of the X-polarization direction response changes. Figure 10

[0105] Fig. 10 shows the response result diagram of the broadband reflection unit working in the state State 13, Figure 11 Fig. 11 shows the response result diagram of the broadband reflection unit working in the state State 13, Figure 11 (a) is a reflection amplitude diagram, Figure 11 (b) is a reflection phase diagram, and Figure 11 It can be seen that, in the 10-15 GHz frequency band, in the central frequency band, the main energy is reflected to the cross-orthogonal linear polarization, and the broadband characteristic is obtained. In this way, by controlling the response to different orthogonal linear polarization incident waves, four different phase states of cross-circular polarization reflection can be generated for circular polarization incident waves, thereby improving the application flexibility in the circular polarization application scenario.

[0106] Then, for a certain specific linear polarization incident wave, the broadband reflection unit can have four different phase responses, so that the broadband reflection unit can exhibit a 2bit, 4-state reflection response for a single linear polarization incident wave, thereby improving the aperture efficiency of the broadband reflection metasurface working in the co-polarization reflection state, and realizing independent response to different polarization incident waves, thereby improving the channel multiplexing efficiency. As shown in Figure 12 Fig. 12 shows the four different phase reflection states exhibited by the broadband reflection unit in response to linear polarization, Figure 12 (a) is a reflection amplitude diagram, Figure 12 (b) is a reflection phase diagram, and Figure 12 It can be seen that, in the 11.5-12.5 GHz frequency band, the four states have high reflection efficiency, and have discrete and flat phase responses. Figure 12

[0107] ​According to electromagnetic theory, the response of the broadband reflecting unit to circularly polarized incident wave can be derived from its response to linearly polarized wave, and the specific formula is:

[0108] R LR = 0.5 * (R xx – R yy – jR yx – jR yx )e －2jψ (1)

[0109] R RR = 0.5 * (R xx + R yy + jR yx – jR yx ) (2)

[0110] R RL = 0.5 * (R xx – R yy + j Ryx + jR xy )e-2 jψ (3)

[0111] R LL = 0.5 * (R xx + R yy – jR yx + j Ryx ) (4)

[0112] Wherein, R (Reflection) represents the reflection response, and ψ is the PB phase generated by the rotation of the unit. It can be seen that when the unit produces cross-polarization response to circularly polarized wave, the response phase produces 180° phase difference every 90° rotation of the unit. More importantly, it can be seen from formula (1) and formula (3) that when R xy = R yx = 0, and R xx and R yy differ by 180°, it produces cross-coupling effect to circularly polarized wave, and the phase response of LCP→RCP and RCP→LCP is consistent, which is called half-wave plate state. In another case, when R xx = R yy = 0, R xy and R yx are not zero, at this time, the phase of RCP→LCP and LCP→RCP differs by 180°, which is called cross-coupling state.

[0113] In this way, the broadband reflection unit can produce different responses to the same circularly polarized incident wave through the half-wave plate working state and the cross-coupling working state of the broadband reflection unit, and thus the entire intelligent reflection array can produce different responses to different circularly polarized incident waves under the same direct current bias, thereby realizing the function of polarization spatial multiplexing.

[0114] As shown in Figure 13 , Figure 13 FIG. 11 is a diagram of the amplitude-phase response of the broadband reflection unit working in State 3, State 5 and State 13 in the frequency band of 11.25-12.25 GHz, Figure 13 (a) is a reflection amplitude graph, Figure 13 (b) is a reflection phase graph, and Figure 13 It can be seen that the flatness of the phase curve is good. When the broadband reflection unit works in State 3, State 5 and the corresponding rotating state, the broadband reflection unit exhibits a good half-wave plate state in the frequency band of 11.25-12.25 GHz. When the broadband reflection unit works in State 13 and the rotating state thereof, it exhibits a good cross-coupling state in the same frequency band. By combining the above states, the final array can produce different beam responses to different circularly polarized incident waves.

[0115] As shown in Figure 14 , the broadband reflection metasurface obtained by arraying the broadband reflection units can realize the array configuration of the required beam of a single polarization through the GS algorithm. When the broadband reflection metasurface works to produce a required beam for a specific polarized incident wave, the process realized by the GS algorithm is as follows: first, a target is designed, i.e., the direction and shape of the far-field beam are designed, and then an ideal near-field amplitude-phase distribution is obtained through far-near field transformation (iFFT) and the near-field amplitude distribution is replaced. Assuming that the irradiation beam is in a Gaussian distribution on the reflection surface, the phase is taken close according to the dispersion. Assuming that the bit number of the broadband reflection unit is 2, corresponding to 4 states, an ideal far-field amplitude-phase distribution is obtained through near-far field transformation (FFT), and then near-far field comprehensive judgment is performed to determine whether the target is met. If not, the far-field distribution is replaced with the target distribution, and an ideal near-field amplitude-phase distribution is obtained through far-near field transformation (iFFT). This cycle is iterated until the far-field velocity and the near-field phase that meet the target requirements are obtained.

[0116] It should be noted that when the broadband reflection unit works in Stste 5-8, the response of one polarization is determined by the bias state of the PIN diode on the other polarization. Therefore, if the target is to make the final array produce specific different functions for different polarized electromagnetic waves under the same bias, the algorithm needs to be adjusted.

[0117] Please refer to Figure 15 , Figure 15is a schematic diagram of the function that can be achieved by the broadband reflection metasurface in the present application, by Figure 5 It can be known that the broadband reflection metasurface composed of the broadband reflection units can produce different responses to different polarized incident waves, and can also produce different responses to different circularly polarized incident waves under the same bias distribution.

[0118] Please refer to Figure 16 In some embodiments, the present application also provides a control method of the broadband reflection metasurface as described above, which comprises the steps of:

[0119] S100, when the broadband reflection unit receives the incident polarized wave, the coupling layer and the adjustable patch layer are excited to be coupled with each other; as described in an embodiment of the broadband reflection metasurface, which will not be repeated here.

[0120] S200, controlling the working state of the PIN diode to manipulate the linearly polarized incident wave and the circularly polarized incident wave. As described in an embodiment of the broadband reflection metasurface, which will not be repeated here.

[0121] In a further implementation of an embodiment, each broadband reflection unit is provided with 4 PIN diodes, and the 4 PIN diodes have 16 states; step S200 comprises the steps of:

[0122] S210, when the broadband reflection unit works in the 13th-16th state, the circularly polarized incident wave is manipulated. As described in an embodiment of the broadband reflection metasurface, which will not be repeated here.

[0123] In a further implementation of an embodiment, when the broadband reflection unit works in the 1st-12th state, it includes the following three types of states:

[0124] The broadband reflection unit works in the 1st-4th state, and two PIN diodes in a certain polarization direction are simultaneously applied with positive bias, in a short-circuit state or an open-circuit state;

[0125] The broadband reflection unit works in the 5th-8th state, and two PIN diodes in a certain polarization direction are applied with positive bias and negative bias respectively, and two PIN diodes in another polarization direction are both in a short-circuit state;

[0126] The broadband reflection unit works in the 9th-12th state, and one PIN diode in a certain polarization direction is applied with positive bias and the other is applied with negative bias, and two PIN diodes in another polarization direction are both in an open-circuit state. As described in an embodiment of the broadband reflection metasurface, which will not be repeated here.

[0127] In a further implementation of the embodiment, when the wideband reflective unit works in the 13th-16th states, the adjacent two PIN diodes are simultaneously applied with positive bias or negative bias, and the X polarization direction and the Y polarization direction are cross-coupled to perform polarization conversion on the incident polarized wave to manipulate the circularly polarized incident wave.

[0128] In summary, the wideband reflective metasurface and the control method thereof have the following beneficial effects:

[0129] By using the multilayer structure of the coupling layer, the modulation layer, the first ground layer, the filter layer, the second ground layer and the control line layer, the isolation of the direct current layer and the alternating current layer of the overall structure of the wideband reflective metasurface is realized, and the influence of the direct current control line layer on the response of the alternating current layer can be effectively reduced.

[0130] By arranging the coupling layer on the modulation layer, when an incident polarized wave is incident on the wideband reflective metasurface, the coupling layer and the modulation layer are coupled, and by controlling the working states of the four PIN diodes, the super wideband response of [0, π] phase modulation on the incident polarized wave and the super wideband response of cross-coupling modulation are realized.

[0131] The single linear polarized incident wave exhibits a 2bit, 4-state reflection response, so that the aperture efficiency of the wideband reflective metasurface working in the co-polarization reflection state can be improved, and the independent response to different polarized incident waves is realized, and the channel multiplexing efficiency is improved.

[0132] By manipulating the responses to different orthogonal linear polarized incident waves, cross-circularly polarized reflection of 4 different phase states of the circularly polarized incident wave can be generated, the application flexibility in the circularly polarized application scenario is improved, so that the linear polarized incident wave and the circularly polarized incident wave can be manipulated, and beamforming and polarization multiplexing can be realized.

[0133] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A broadband reflective metasurface comprising a plurality of broadband reflective cells arranged in an array, wherein, The wideband reflection unit comprises a coupling layer, a modulation layer, a first ground layer, a filter layer, a second ground layer and a control line layer; wherein the modulation layer comprises an adjustable patch layer and four diodes arranged on the adjustable patch layer, and each two diodes act on X polarization direction and Y polarization direction respectively, and the diodes have different responses to different incident polarized waves under different control bias; The coupling layer is arranged opposite to the adjustable patch layer, and is used for coupling with the adjustable patch layer after being excited by the incident polarized wave; The first ground layer is connected with the adjustable patch layer; The filter layer is connected with the adjustable patch layer, and is used for filtering out harmonics; The second ground layer is connected with the filter layer; The control line layer is connected with the diodes, and is used for controlling the working state of the diodes; The diodes are PIN diodes, the structure of the wideband reflection unit and the wideband reflection super surface is changed by controlling the working state of the PIN diodes, so as to control linearly polarized incident wave and circularly polarized incident wave, and the four PIN diodes have 16 states, including the following four types: Two PIN diodes in a certain polarization direction are simultaneously applied with positive bias, and are in short-circuit state or open-circuit state; Two PIN diodes in a certain polarization direction are applied with positive bias and negative bias respectively, and two PIN diodes in another polarization direction are in short-circuit state; One PIN diode in a certain polarization direction is applied with positive bias, and one PIN diode in the certain polarization direction is applied with negative bias, and two PIN diodes in another polarization direction are in open-circuit state; Two adjacent PIN diodes are simultaneously applied with positive bias or negative bias.

2. The broadband reflective metasurface of claim 1, wherein, The adjustable patch layer comprises a first dielectric plate, a square patch and a T-shaped patch; The first dielectric plate is arranged on the first ground layer; The square patch is arranged on the first dielectric plate, and the square patch is connected with the first ground layer through a grounding needle; The T-shaped patch is arranged with four T-shaped patches and arranged around the square patch, and the T-shaped patch is connected with the filter layer through a bias needle; The positive electrode of the PIN diode is connected with the T-shaped patch, and the negative electrode of the PIN diode is connected with the square patch.

3. The broadband reflective metasurface of claim 1, wherein, The coupling layer comprises a second dielectric plate and a coupling patch; wherein, The second dielectric plate is arranged on the modulation layer; The coupling patch is arranged on the second dielectric plate.

4. The broadband reflective metasurface of claim 2, wherein, The filter layer comprises a third dielectric plate, four filter inductors and a zigzag microstrip line; The filter inductor is arranged on the third dielectric plate; The zigzag microstrip line is arranged on the third dielectric plate, connected with the filter inductor, and connected with the T-shaped patch through the bias needle.

5. The broadband reflective metasurface of claim 4, wherein, The control line layer comprises a first control line layer and a second control line layer; Two direct current bias control traces are arranged on the first control line layer and the second control line layer respectively, and are connected with the PIN diode respectively; wherein the direct current bias control trace is connected with the PIN diode through a direct current control trace connection needle.

6. The broadband reflective metasurface of claim 5, wherein, The wideband reflection unit further comprises a second ground layer and a fourth dielectric plate; wherein, The second ground layer is arranged on the fourth dielectric plate; wherein the first control line layer is arranged on the third dielectric plate, and the second control line layer is arranged on the fourth dielectric plate.

7. The broadband reflective metasurface of claim 6, wherein, The broadband reflection unit further comprises a first adhesive plate and a second adhesive plate; wherein The first adhesive plate is connected between the first ground layer and the third dielectric plate; The second adhesive plate is connected between the second ground layer and the fourth dielectric plate.

8. The broadband reflective metasurface of claim 1, wherein, The array mode on the broadband reflection metasurface is a 4*4 array, an 8*8 array or a 16*16 array.

9. A method of controlling a broadband reflective metasurface according to any one of claims 1-8, characterized in that, Comprise: When the broadband reflection unit receives an incident polarized wave, the coupling layer and the adjustable patch layer are excited to be coupled with each other; The working state of the diode is controlled to manipulate linearly polarized incident waves and circularly polarized incident waves.

10. The method of claim 9, wherein, The diode is a PIN diode, and each broadband reflection unit is provided with four PIN diodes, and the four PIN diodes have 16 states; the step of controlling the working state of the PIN diode to manipulate linearly polarized incident waves and circularly polarized incident waves comprises: When the broadband reflection unit works in the 13th-16th state, the circularly polarized incident wave is manipulated.

11. The method of claim 10, wherein, When the broadband reflection unit works in the 1st-12th state, it includes three types of states: The broadband reflection unit works in the 1st-4th state, two PIN diodes in a certain polarization direction are simultaneously subjected to positive bias, in a short-circuit state or an open-circuit state; The broadband reflection unit works in the 5th-8th state, two PIN diodes in a certain polarization direction are subjected to positive bias and negative bias respectively, and two PIN diodes in another polarization direction are both in a short-circuit state; The broadband reflection unit works in the 9th-12th state, one PIN diode in a certain polarization direction is subjected to positive bias and one is subjected to negative bias, and two PIN diodes in another polarization direction are both in an open-circuit state.

12. The method of claim 10, wherein, When the broadband reflection unit works in the 13th-16th state, two adjacent PIN diodes are simultaneously subjected to positive bias or negative bias, the X polarization direction and the Y polarization direction are cross-coupled, the polarization of the incident polarized wave is converted, and the circularly polarized incident wave is manipulated.

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