Dual-polarized x-band reconfigurable intelligent surface

Abstract

The application discloses a dual-polarized X-band reconfigurable intelligent metasurface, and the intelligent metasurface comprises: 2 n 2 basic unit cycles arranged in period, and m 2 units constitute a subarray, wherein the subarray is controlled by the same signal, and each subarray is provided with a control signal by a control circuit. The application introduces a variable capacitor diode as a capacitance adjustable device, so that the phase of the reflected wave of the electromagnetic wave incident to the application can be continuously and dynamically adjusted. The structure is designed as a symmetrical structure, so that the dual-polarization regulation and control function is realized.

Description

Technical Field

[0001] This invention belongs to the field of reflective reconfigurable smart metasurface (RIS) technology, and particularly relates to a dual-polarized X-band reconfigurable smart metasurface. Background Technology

[0002] Reconfigurable smart metasurfaces have attracted significant attention due to their powerful ability to manipulate electromagnetic waves in real time. Reflective reconfigurable smart metasurfaces can control the amplitude, phase, polarization, frequency, and propagation direction of reflected waves. Because of their enormous potential in controlling the propagation environment, reconfigurable smart metasurfaces are expected to improve the performance of wireless communication networks, thus gaining widespread attention in the field of wireless communication. Existing reconfigurable smart metasurface designs are primarily single-polarized. When single-polarized reconfigurable smart metasurfaces are used to assist wireless communication, energy loss due to polarization mismatch leads to reduced array efficiency and the signal-to-noise ratio improvement does not achieve the expected results. Furthermore, existing dual-polarized reconfigurable smart metasurfaces face problems such as high DC loss, large reflection loss, and difficulties in designing the feeding circuit. Summary of the Invention

[0003] The purpose of this invention is to provide a dual-polarized X-band reconfigurable smart metasurface, which, compared with a single-polarized reconfigurable smart metasurface, can greatly improve signal strength and increase transmission channel utilization under the same array size.

[0004] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows:

[0005] A dual-polarized X-band reconfigurable smart metasurface, the smart metasurface comprising: n 2 The basic units are arranged periodically, each m 2 Each unit forms a subarray, wherein the subarray is controlled by the same signal, and the control signal for each subarray is provided by the control circuit.

[0006] The basic unit, from top to bottom, includes a first layer structure, a second layer structure, a third layer structure, a fourth layer structure, a fifth layer structure, and a sixth layer structure:

[0007] The first layer structure includes a large metal patch placed in the center, the upper end of which is connected to a first varactor diode, which is connected to a first small metal patch; the right end of the large metal patch is connected to a second varactor diode, which is connected to a second small metal patch; the lower end of the large metal patch is connected to a third varactor diode, which is connected to a third small metal patch; and the left end of the large metal patch is connected to a fourth varactor diode, which is connected to a fourth small metal patch.

[0008] The second layer structure includes a first dielectric layer, the first layer structure is attached to the first dielectric layer, the first metal pillar penetrates the first dielectric layer and connects the first layer structure and the third layer structure, and the second metal pillar penetrates the first dielectric layer and connects the first layer structure and the sixth layer structure.

[0009] The third layer structure includes a metal ground, which serves to reflect electromagnetic waves. The first small metal patch, the second small metal patch, the third small metal patch, and the fourth small metal patch are connected to the first metal post through thin metal wires, and then the first metal post is connected to the metal ground.

[0010] The fourth layer is a prepreg, used to connect the third and fifth layers. The second metal pillar penetrates the prepreg.

[0011] The fifth layer is the second dielectric layer, the sixth layer is attached to the second dielectric layer, and the second metal pillar penetrates the second dielectric layer;

[0012] The sixth layer structure is a DC metal feed line, and the large metal patch of the first layer structure is connected to the fifth layer DC metal feed line through a second metal post.

[0013] Furthermore, the first varactor diode, the second varactor diode, the third varactor diode, and the fourth varactor diode generate a capacitance change of 0.6 to 2.6 pF when the reverse feed voltage changes from 0 to 30 V.

[0014] Furthermore, under different control voltages, at a given frequency, the phase variation range of the electromagnetic wave back reflection exceeds 180°.

[0015] Furthermore, the different control voltages specifically include: 0V and 30V.

[0016] Furthermore, the first small metal patch, the second small metal patch, the third small metal patch, the fourth small metal patch and the central large metal patch are processed with the first dielectric layer using standard PCB processes, and the third metal ground layer is processed with the second dielectric layer using standard PCB processes.

[0017] Furthermore, the first varactor diode, the second varactor diode, the third varactor diode, and the fourth varactor diode are soldered to the surfaces of the first small metal patch, the second small metal patch, the third small metal patch, the fourth small metal patch, and the central large metal patch using low-temperature solder paste.

[0018] The dual-polarized X-band reconfigurable smart metasurface of the present invention has the following advantages:

[0019] 1. This invention uses a loaded varactor tube, which can achieve continuous phase control from 0 to 180° under continuous voltage regulation from 0 to 30V.

[0020] 2. This invention has a symmetrical structure, which makes it easy to achieve the function of dual polarization.

[0021] 3. This invention utilizes multiple basic units to form a basic subarray, which is controlled by the same signal. This reduces the interference caused by different boundaries on the reflection coefficient of the units, and also reduces the design complexity of the power supply network. Correspondingly, compared with the prior art, this invention can achieve high-efficiency phase modulation. Attached Figure Description

[0022] Figure 1 This is a top view of the dual-polarized X-band reconfigurable smart metasurface provided in an embodiment of the present invention;

[0023] Figure 2 A side view of the dual-polarized X-band reconfigurable smart metasurface provided in an embodiment of the present invention;

[0024] Figure 3 This is a bottom view of the dual-polarized X-band reconfigurable smart metasurface provided in an embodiment of the present invention;

[0025] Figure 4 Top view of each part of the dual-polarized X-band reconfigurable smart metasurface provided by the present invention;

[0026] Figure 5 Side views of various parts of the dual-polarized X-band reconfigurable smart metasurface provided by the present invention;

[0027] Figure 6 Bottom views of various parts of the dual-polarized X-band reconfigurable smart metasurface provided by this invention;

[0028] Figure 7 The graph shows the amplitude of the dual-polarized X-band reconfigurable smart metasurface provided in this embodiment of the invention as a function of frequency under 1-bit encoding conditions (control voltages 0V and 30V).

[0029] Figure 8 The graph shows the phase variation of the dual-polarized X-band reconfigurable smart metasurface provided in this embodiment of the invention under 1-bit encoding conditions (control voltages 0V and 30V) as a function of frequency.

[0030] The markings in the diagram are as follows: 1. First varactor diode; 2. Second varactor diode; 3. Third varactor diode; 4. Fourth varactor diode; 5. First metal pillar; 6. Second metal pillar; 7. First dielectric layer; 8. Second dielectric layer; 9. DC metal feed line; 10. Large metal patch; 11. First small metal patch; 12. Second small metal patch; 13. Third small metal patch; 14. Fourth small metal patch; 15. Metal ground; 16. Thin metal wire. Detailed Implementation

[0031] To better understand the purpose, structure, and function of this invention, the following detailed description of a dual-polarized X-band reconfigurable smart metasurface, in conjunction with the accompanying drawings, is provided.

[0032] Example 1

[0033] See Figures 1-8 This embodiment provides a dual-polarized X-band reconfigurable smart metasurface, specifically including: n 2 The basic units are arranged periodically, each m 2 Each unit forms a subarray, which is controlled by the same signal, and each subarray is provided with a control signal by a control circuit.

[0034] In this embodiment, the basic unit includes, from top to bottom, the following:

[0035] The first layer structure includes a large metal patch 10 placed at the center. The upper end of the large metal patch 10 is connected to a first varactor diode 1, which is connected to a first small metal patch 11. The right end of the large metal patch 10 is connected to a second varactor diode 2, which is connected to a second small metal patch 12. The lower end of the large metal patch 10 is connected to a third varactor diode 3, which is connected to a third small metal patch 13. The left end of the large metal patch 10 is connected to a fourth varactor diode 4, which is connected to a fourth small metal patch 14.

[0036] The second layer structure includes a first dielectric layer 7, the first layer structure is attached to the first dielectric layer 7, the first metal pillar 5 penetrates the first dielectric layer 7 and connects the first layer structure and the third layer structure, and the second metal pillar 6 penetrates the first dielectric layer 7 and connects the first layer structure and the sixth layer structure.

[0037] The third layer structure includes a metal ground 15, which serves to reflect electromagnetic waves. The first small metal patch 11, the second small metal patch 12, the third small metal patch 13, and the fourth small metal patch 14 are connected to the first metal post 5 through a metal wire 16, and then the first metal post 5 is connected to the metal ground 15.

[0038] The fourth layer is a prepreg 17, which is used to connect the third and fifth layers. The second metal pillar 6 penetrates the prepreg 17.

[0039] The fifth layer is the second dielectric layer 8, the sixth layer is attached to the second dielectric layer 8, and the second metal pillar 6 penetrates the second dielectric layer 8;

[0040] The sixth layer structure is a DC metal feed line 9, and the large metal patch 10 of the first layer structure is connected to the fifth layer DC metal feed line 9 through a second metal post 6.

[0041] The first varactor diode 1, the second varactor diode 2, the third varactor diode 3, and the fourth varactor diode 4 generate a capacitance change of 0.65 to 2.6 pF when the reverse feed voltage changes from 0 to 30 V.

[0042] Under different control voltages, at a given frequency, the phase variation of the electromagnetic wave back reflection exceeds 180°.

[0043] The different control voltages specifically include: 0V and 30V.

[0044] The first small metal patch 11, the second small metal patch 12, the third small metal patch 13, the fourth small metal patch 14 and the central large metal patch 10 are processed with the first dielectric layer 7 using standard PCB technology, and the third metal ground layer 15 is processed with the second dielectric layer 8 using standard PCB technology.

[0045] The varactor diode 2 is soldered to the surface of the first small metal patch 11, the second small metal patch 12, the third small metal patch 13, the fourth small metal patch 14 and the central large metal patch 10.

[0046] like Figures 1 to 4 As shown, in this embodiment, the dimensions of the basic unit, large and small patches, and DC feeder are:

[0047] The basic unit has a length of px = 10mm on the x-axis and a length of py = 10mm on the y-axis. The width of the central large patch is w1 = 3.88mm, the width of the small patch is w2 = 1.73mm, the length of the small patch is w3 = 2.27mm, the short segment of the grounding DC feeder is w4 = 0.63mm, the long segment of the grounding DC feeder is w5 = 4.6mm, the width of the grounding DC feeder is w6 = 0.2mm, the short segment of the DC feeder is w7 = 4.1mm, the long segment of the DC feeder is w8 = 5.1mm, the width of the DC feeder is w9 = 0.2mm, the thickness of the first dielectric layer is h1 = 1.5mm, the thickness of the prepreg is h2 = 0.1mm, and the thickness of the second dielectric layer is h3 = 0.5mm.

[0048] This embodiment provides a dual-polarized X-band reconfigurable smart metasurface. Under normal electromagnetic wave incidence, the phase of the reflected electromagnetic wave can be changed by altering the bias voltage on the varactor diode 2. Specifically:

[0049] For an N-bit encoded smart metasurface, if its initial phase is φ = φ0, then the phase of the nth state is φ = φ0 + 360° × n / 2 N ,n∈[0,N-1], which means that an N-bit encoded smart metasurface must at least satisfy 0~360°×(2 N -1) / 2 NThe phase change range can be obtained, and intervals of 360° / 2 can be obtained. N 2 N Each phase state, more specifically:

[0050] For a 1-bit encoded smart metasurface, it should satisfy a phase change range of 0 to 180° and be able to obtain two phase states with a 180° interval.

[0051] A 1-bit coded smart metasurface exhibits two coded states under normal incidence at 9.8 GHz: 1 and 2, with the amplitude and phase of these two coded states corresponding to... Figure 7 and Figure 8 The values ​​shown are 0V and 30V. The reflection amplitude is greater than -3dB in each coded state, thus achieving efficient reflection phase control.

[0052] This embodiment also provides a specific testing method, which includes:

[0053] Step S1: Place the transmitting antenna and the receiving antenna on both sides of the normal symmetry of the dual-polarized X-band reconfigurable smart metasurface provided in this embodiment, and the distance between them and the dual-polarized X-band reconfigurable smart metasurface needs to exceed 3m.

[0054] Step S2: Apply a voltage source to the control circuit of the dual-polarized X-band reconfigurable smart metasurface;

[0055] Step S3: Connect the transmitting antenna and the receiving antenna to ports 1 and 2 of the vector network analyzer using RF transmission lines, respectively.

[0056] Step S4: Record the amplitude and phase of the electromagnetic waves received under different control voltages;

[0057] Step S5: Replace the dual-polarized X-band reconfigurable smart metasurface provided in this embodiment with a metal plate of the same size;

[0058] Step S6: Record the amplitude and phase of the received electromagnetic wave;

[0059] Step S7: Using the amplitude and phase of the electromagnetic wave received when the metal plate is placed as a reference, divide the amplitude received under different voltages when the dual-polarized X-band reconfigurable smart metasurface is placed by the amplitude of the electromagnetic wave received when the metal plate is placed to obtain the relative amplitude received when the dual-polarized X-band reconfigurable smart metasurface in this embodiment is placed under the corresponding voltage. Correspondingly, subtract the phase of the electromagnetic wave received when the metal plate is placed from the phase received under different voltages when the dual-polarized X-band reconfigurable smart metasurface in this embodiment to obtain the relative phase received when the dual-polarized X-band reconfigurable smart metasurface is placed under the corresponding voltage.

[0060] In summary, this invention proposes a dual-polarized X-band reconfigurable smart metasurface. By loading a varactor diode in each unit, the system can achieve a phase shift range of 0° to 180° and two coded states spaced 180° apart. Dual-polarization control is achieved by designing the structure as a symmetrical structure.

[0061] Any aspects of this invention not described in detail are well-known to those skilled in the art.

[0062] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A dual-polarized X-band reconfigurable smart metasurface, characterized in that, The intelligent metasurface includes: n 2 The basic units are arranged periodically, each m 2 Each unit forms a subarray, wherein the subarray is controlled by the same signal, and the control signal for each subarray is provided by the control circuit. The basic unit, from top to bottom, includes a first layer structure, a second layer structure, a third layer structure, a fourth layer structure, a fifth layer structure, and a sixth layer structure: The first layer structure includes a large metal patch (10) placed in the center. The upper end of the large metal patch (10) is connected to a first varactor diode (1), which is connected to a first small metal patch (11). The right end of the large metal patch (10) is connected to a second varactor diode (2), which is connected to a second small metal patch (12). The lower end of the large metal patch (10) is connected to a third varactor diode (3), which is connected to a third small metal patch (13). The left end of the large metal patch (10) is connected to a fourth varactor diode (4), which is connected to a fourth small metal patch (14). The second layer structure includes a first dielectric layer (7), the first layer structure is attached to the first dielectric layer (7), the first metal pillar (5) penetrates the first dielectric layer (7) and connects the first layer structure and the third layer structure, and the second metal pillar (6) penetrates the first dielectric layer (7) and connects the first layer structure and the sixth layer structure. The third layer structure includes a metal ground (15), which serves to reflect electromagnetic waves. The first small metal patch (11), the second small metal patch (12), the third small metal patch (13), and the fourth small metal patch (14) are connected to the first metal post (5) through a metal wire (16), and then connected to the metal ground (15) through the first metal post (5). The fourth layer is a prepreg (17), which is used to connect the third layer and the fifth layer. The second metal pillar (6) penetrates the prepreg (17). The fifth layer is the second dielectric layer (8), the sixth layer is attached to the second dielectric layer (8), and the second metal pillar (6) penetrates the second dielectric layer (8); The sixth layer structure is a DC metal feed line (9), and the large metal patch (10) of the first layer structure is connected to the fifth layer DC metal feed line (9) through a second metal post (6).

2. The dual-polarized X-band reconfigurable smart metasurface according to claim 1, characterized in that, The first varactor diode (1), the second varactor diode (2), the third varactor diode (3), and the fourth varactor diode (4) generate a capacitance change of 0.6 to 2.6 pF when the reverse feed voltage changes from 0 to 30 V.

3. The dual-polarized X-band reconfigurable smart metasurface according to claim 2, characterized in that, Under different control voltages, at a given frequency, the phase variation of the electromagnetic wave back reflection exceeds 180°.

4. The dual-polarized X-band reconfigurable smart metasurface according to claim 3, characterized in that, The different control voltages specifically include 0V and 30V.

5. The dual-polarized X-band reconfigurable smart metasurface according to claim 4, characterized in that, The first small metal patch (11), the second small metal patch (12), the third small metal patch (13), the fourth small metal patch (14) and the central large metal patch (10) are processed with the first dielectric layer (7) using standard PCB technology, and the third metal ground layer (15) and the second dielectric layer (8) are processed with standard PCB technology.

6. The dual-polarized X-band reconfigurable smart metasurface according to claim 5, characterized in that, The first varactor diode (1), the second varactor diode (2), the third varactor diode (3) and the fourth varactor diode (4) are soldered to the surfaces of the first small metal patch (11), the second small metal patch (12), the third small metal patch (13), the fourth small metal patch (14) and the central large metal patch (10).

7. The dual-polarized X-band reconfigurable smart metasurface according to claim 1, characterized in that, The materials of the first dielectric layer (7) and the second dielectric layer (8) are F4B.

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