A polarization-insensitive, sensing, phase-modulating, and reconfigurable smart metasurface

Abstract

The present invention discloses a polarization-insensitive perception and phase-modulation integrated reconfigurable intelligent metasurface, which includes: N×N basic units arranged periodically, wherein each basic unit is regulated by a different control signal. The present invention introduces a Pin tube as an adjustable device, so that the phase of the reflected wave of the electromagnetic wave incident on the present invention can achieve two states with a phase difference of 180°, and its phase control is accurate and can be switched quickly; the present invention introduces a metal patch and a thin metal strip that are symmetrical with both the x-axis and the y-axis as the first layer structure, so that the present invention can work in normal incidence and oblique incidence, and is insensitive to the polarization direction of the incident wave. The present invention introduces an asymmetric slotted design, so that the perception unit can simultaneously guarantee a high perception energy receiving efficiency in two states of 1 bit. In summary, compared with the traditional design, the present invention has a higher perception ability and realizes the integration of perception and phase modulation.

Description

Technical Field

[0001] The present invention relates to the technical field of reconfigurable intelligent supersurfaces, and in particular to a 1-bit sensing phase-modulation integrated reconfigurable intelligent supersurface that is insensitive to the polarization of incident electromagnetic waves. Background Art

[0002] Reconfigurable smart metasurfaces have received extensive attention in the wireless field due to their great potential in improving channels and communication quality, and improving the performance of wireless communication networks. Traditional reconfigurable smart metasurfaces cannot adaptively adjust their own coding states according to the surrounding electromagnetic environment. To achieve intelligent control of metasurfaces, a key step is to sense and collect data from the environment. However, most of the previously designed sensor-based sensing metasurfaces can only sense and regulate electromagnetic signals of different types or different frequency bands (for example, manipulating electromagnetic waves to sense light waves, manipulating electromagnetic waves of one frequency band to sense electromagnetic waves of another frequency band), but cannot sense and regulate electromagnetic signals of the same type or frequency band, so their application value is limited. Secondly, the sensing ability of the previously proposed sensing metasurfaces is limited, and they can only sense one or several states in multiple reconfigurable states. Therefore, a metasurface that can sense incoming waves in each phase modulation state is urgently needed to be studied and designed. In addition, in actual wireless electromagnetic communications, receivers and transmitters need to be insensitive to the polarization direction and incident angle of the incident electromagnetic wave to achieve better communication quality. Therefore, a 1-bit sensing phase-modulation integrated reconfigurable intelligent metasurface that is insensitive to the incident angle and polarization direction needs to be studied and designed urgently. Summary of the invention

[0003] Technical problem: The purpose of the present invention is to provide a polarization-insensitive perception-phase-modulation integrated reconfigurable intelligent metasurface to solve the technical problems mentioned in the background technology and to perform real-time, dynamic and rapid regulation of the reflected waves of the electromagnetic waves incident on the present invention.

[0004] Technical solution: The purpose of the present invention is to provide a polarization-insensitive sensing and phase-modulating integrated reconfigurable intelligent metasurface, comprising: N×N basic units arranged periodically, wherein each basic unit is provided with different control signals by a control circuit; 1-bit reflection phase control of the incident electromagnetic wave is performed, and 1-bit incoming wave sensing is performed at the same time, thereby realizing the integration of sensing and phase modulation.

[0005] The basic unit includes, from top to bottom:

[0006] The first layer is a metal pattern layer including a pin tube A, a pin tube B, a metal patch, an asymmetric slot, a thin metal strip A and a thin metal strip B, wherein the two pin tubes are of the same model and are perpendicular to each other, the two thin metal strips are of the same size and are perpendicular to each other, and the two thin metal strips and the metal patch are connected in series by the pin tube A and the pin tube B;

[0007] The second layer is an upper dielectric substrate;

[0008] The third layer is the metal layer;

[0009] The fourth layer is the bonding layer;

[0010] The fifth layer is the lower dielectric substrate;

[0011] The sixth layer is the feeder layer, which includes a sensing microstrip line and a DC feeder, wherein the DC feeder inputs a bias voltage to the Pin tube, and the sensing microstrip line receives the energy signal of the incident wave for sensing; the DC feeder is connected in series with an inductor and a capacitor; one end of the capacitor is connected to the DC feeder, and the other end is connected to the metal layer through a blind hole;

[0012] Among them, metal holes are respectively arranged between the two thin metal strips in the first layer and the third layer, and the metal holes all have DC bias to provide DC voltage for the Pin tube; a metal center through hole is arranged between the metal patch in the first layer and the sixth layer to provide DC bias and sense the energy of the incident wave.

[0013] The Pin tube is in a conducting state when the bias voltage is 1V, and is in a non-conducting state when the bias voltage is 0V; the internal equivalent circuits of the Pin tube in the conducting and non-conducting states are different, thereby forming different responses to the incident electromagnetic waves.

[0014] For the Pin tube, at a given frequency point, the phase interval of the electromagnetic wave back reflection of the Pin tube in the two states of conduction and non-conduction is 180°.

[0015] The Pin tube can intelligently sense the energy of the incident electromagnetic wave in both the conducting and non-conducting states; a small amount of incident electromagnetic wave energy is transmitted from the metal center through hole to the sensing microstrip line, and then finally transmitted from the sensing microstrip line to the detector chip.

[0016] The detector chip converts the radio frequency signal on the sensed microstrip line into an output voltage corresponding to the energy level of the radio frequency signal.

[0017] The size of the basic unit is P1=25.8mm, the size of the metal patch is P2=25.8mm, the long side of the depression of the metal patch is L1=3.4mm, the short side of the depression of the metal patch is L2=1.65mm, the line width of the thin metal strip is W=0.7mm, the size of the asymmetric slot is P3=1.05, the slot spacing is S=0.4mm, and the length of the thin metal strip is L3=2.18mm.

[0018] The thickness of the upper dielectric substrate is H1=3 mm, the thickness of the bonding layer is H2=0.1 mm, the thickness of the lower dielectric substrate is H3=1 mm, the diameter of the metal center through hole is 0.6 mm, and the diameters of the metal hole and the blind hole are 0.4 mm.

[0019] Beneficial effect: The advantages of the present invention are:

[0020] 1. The principles of the present invention are divided into phase modulation principle and perception principle. Among them, the phase modulation principle is: by changing the forward bias voltage on the Pin tube, the equivalent circuit inside the Pin tube changes. Based on this, the present invention can perform real-time, dynamic and rapid regulation on the reflected wave of the electromagnetic wave incident on the present invention. The perception principle is: by introducing an asymmetric slot at the center of the above-mentioned metal patch, a small amount of incident wave energy is transmitted through the central through hole and the perception microstrip line in turn to the detector chip to complete the perception of the incident wave energy.

[0021] 2. The present invention independently regulates all metasurface units in the reconfigurable intelligent metasurface, greatly increasing the degree of control freedom of the metasurface and enhancing the metasurface's ability to regulate incident electromagnetic waves.

[0022] 3. Compared with the prior art, the present invention can realize 1-bit phase modulation and sensing integration, and its sensing capability is applicable to both the conducting and non-conducting states of the Pin tube. In addition, its phase modulation capability and sensing capability are both polarization insensitive and incident angle insensitive. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of the reconfigurable sensing metasurface provided in Example 1;

[0024] Figure 2 This is a front view of the reconfigurable sensing metasurface provided in Example 1;

[0025] Figure 3 A back view of the reconfigurable sensing metasurface provided in Example 1;

[0026] Figure 4 A top view of the reconfigurable sensing metasurface provided in Example 1 and a schematic diagram of its dimension markings;

[0027] Figure 5A graph showing the reflection amplitude of each state (2) of the reconfigurable sensing metasurface provided in Example 1 under 1-bit coding as a function of frequency;

[0028] Figure 6 A graph showing the reflection phase of two states of the reconfigurable sensing metasurface provided in Example 1 under 1-bit coding as a function of frequency;

[0029] Figure 7 A graph showing the variation of the amplitude of the radio frequency signal on the DC feeder in two states of the reconfigurable sensing metasurface provided in Example 1 under 1-bit encoding as a function of the frequency;

[0030] Figure 8 A curve diagram showing the variation of the amplitude of the radio frequency signal on the sensing microstrip line in two states of the reconfigurable sensing metasurface provided in Example 1 under 1-bit coding as a function of the frequency;

[0031] Fig. 9 is a graph showing changes in reflection amplitude and phase interval of two states of the reconfigurable sensing metasurface provided in Example 1 with 1-bit coding as a function of incident angle under TE polarized incident waves;

[0032] Fig.10 is a graph showing changes in reflection amplitude and phase interval of two states of the reconfigurable sensing metasurface provided in Example 1 with 1-bit coding as a function of the incident angle under TM polarized incident waves;

[0033] Fig.11 is a graph showing how the amplitude of the RF signal on the DC feeder varies with the incident angle in two states of the reconfigurable sensing metasurface provided in Example 1 under 1-bit coding, and how the amplitude of the RF signal on the sensing microstrip line varies with the incident angle under TE polarized incident waves;

[0034] Fig.12 The graphs show that under TM polarized incident waves, the amplitude of the RF signal on the DC feed line of the reconfigurable sensing metasurface provided in Example 1 varies with the incident angle in 2 states under 1-bit coding, and the amplitude of the RF signal on the sensing microstrip line varies with the incident angle.

[0035] The figure includes: metal pattern layer 1, Pin tube A1.1, Pin tube B1.2, metal patch 1.3, asymmetric slot 1.4, thin metal strip A1.5 and thin metal strip B1.6;

[0036] Upper dielectric substrate 2; metal layer 3; adhesive layer 4; lower dielectric substrate 5;

[0037] Feed line layer 6, sensing microstrip line 6.1, DC feed line 6.2, inductor 6.3, capacitor 6.4;

[0038] Metal hole 7, central through hole 8, blind hole 9, detector chip 10; sensing microstrip line 11. DETAILED DESCRIPTION

[0039] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0040] Example 1

[0041] See also Figure 1-Figure 4 This embodiment provides a 1-bit sensing phase-modulation integrated reconfigurable smart metasurface that is insensitive to incident angle and polarization direction, specifically comprising: N×N basic units are periodically arranged, wherein each basic unit is controlled by a different signal, and each unit is provided with a control signal by a control circuit.

[0042] Specifically, in this embodiment, the basic unit includes, from top to bottom:

[0043] The first layer is the patch structure layer 1, which includes Pin tube A1.1, Pin tube B1.2, metal patch 1.3, asymmetric slot 1.4, thin metal strip A1.5 and thin metal strip B1.6; two Pin tubes connect two thin metal strips and a metal patch in series. The asymmetric slot is located at the center of the metal patch.

[0044] The second layer is an upper dielectric substrate 2;

[0045] The third layer is metal layer 3;

[0046] The fourth layer is an adhesive layer 4;

[0047] The fifth layer is a lower dielectric substrate 5;

[0048] The sixth layer is the routing layer 6, and the feeder layer includes a sensing microstrip line 6.1 and a DC feeder line 6.2, wherein the DC feeder line serves to input a bias voltage to the Pin tube, and the sensing microstrip line 11 serves to receive the energy of the incident wave for sensing; the DC feeder line is serially connected with an inductor 6.3 and a capacitor 6.4; one end of the capacitor is connected to the DC feeder line, and the other end is connected to the metal layer through a blind hole 9;

[0049] Specifically, in this embodiment, the models of the Pin tube A and the Pin tube B used are both SMP1320-040LF, and this model of Pin tube has two states of non-conduction and conduction when the forward bias voltage is 0v and 1v respectively.

[0050] Specifically, in this embodiment, when the bias voltage is 0 V and 1 V, at a given frequency point, the phase interval of the electromagnetic wave back reflection is 180°.

[0051] Specifically, in this embodiment, when the bias voltage is 0 V and 1 V, at a given frequency point, the amplitude of the electromagnetic wave back reflection is greater than -2 dB.

[0052] Specifically, in this embodiment, the energy amplitude of the radio frequency signal on the DC feeder line is less than -40 dB, and the radio frequency signal on the sensing microstrip line is greater than -11 dB.

[0053] Specifically, the metal-dielectric-metal-dielectric-metal five-layer sandwich structure provided in this embodiment can be easily prepared using standard printed circuit board (PCB) technology. More specifically:

[0054] F4B dielectric plate with a thickness of 3 mm (ε r =3, tanδ=0.0017) as the upper dielectric substrate 5, in which two metal holes 7 with a diameter of 0.4 mm and a metal central through hole 8 with a diameter of 0.6 mm are provided; a F4B dielectric plate with a thickness of 1 mm (ε r =2.2, tanδ=0.001) as the lower dielectric substrate, in which a metal hole 7 with a diameter of 0.4 mm and a metal center through hole 8 are provided;

[0055] The surface copper layer of the metal pattern layer has a thickness of 0.035 mm and is mainly composed of a metal patch, an asymmetric slot and two thin metal strips; wherein the two thin metal strips are oriented perpendicular to each other to achieve polarization insensitivity.

[0056] The metal layer is a complete copper layer coated with a thickness of 0.035 mm to realize a reflective reconfigurable metasurface;

[0057] The 0.1mm thick adhesive layer bonds the metal layer and the lower dielectric substrate together to form a whole;

[0058] The DC feed line and sensing microstrip line in the routing layer are both copper wires with a thickness of 0.035mm and a line width of 0.5mm. The sensing microstrip line has a chamfer with a cut angle of 0.5mm at the right angle bend;

[0059] The DC feed line has a series inductor of 20nH and a parallel capacitor of 5pF to achieve good isolation of RF signals.

[0060] Among them, Pin tube A and Pin tube B connect the metal patch and thin metal strip A and thin metal strip B in series, and are used as state-adjustable phase tuning devices. When the forward bias voltage is greater than the threshold, the Pin tube is turned on; when the forward bias voltage is less than the threshold, the Pin tube is not turned on. The two states of the above-mentioned Pin tube have different equivalent circuits, which can tune the resonant frequency of the reflected electromagnetic wave or control the phase shift of the electromagnetic wave at a specific frequency; the metal patch is composed of a rectangular metal patch with a depression at the center of the four sides; the asymmetric slot at the center of the metal patch is evolved by rotating and replicating the U-shaped slot, which can transfer part of the energy of the incident electromagnetic wave to the central through hole, and further to the sensing microstrip line, and finally enter the detector chip 10; the metal central through hole is a metal hole with a diameter of 0.6mm, connecting the first layer and the sixth layer, which can provide a bias voltage for the Pin tube, and can also transmit RF signals to sense the incident wave; the LTC5530 detector chip used can convert the RF signal on the sensing microstrip line into an output voltage relative to the energy size of its RF signal. Finally, the external circuit can sense the incident electromagnetic wave by detecting the output voltage of the detector chip.

[0061] Specifically, Figure 1-Figure 4 As shown, in this embodiment, the specific dimensions of the metal pattern layer, the upper dielectric plate, the lower dielectric plate, the feeder layer and each metal hole of the sensing unit are:

[0062] The size of the basic unit is P1=25.8mm, the size of the metal patch is P2=25.8mm, the long side of the depression of the metal patch is L1=3.4mm, the short side of the depression of the metal patch is L2=1.65mm, the line width of the thin metal strip is W=0.7mm, the size of the asymmetric slot is P3=1.05, the slot spacing is S=0.4mm, the length of the thin metal strip is L3=2.18mm, the thickness of the upper dielectric substrate is H1=3mm, the thickness of the bonding layer is H2=0.1mm, the thickness of the lower dielectric substrate is H3=1mm, the diameter of the center through hole is 0.6mm, and the diameters of the metal holes and blind holes are 0.4mm.

[0063] Specifically, in order to make the 1-bit sensing phase-modulation integrated reconfigurable smart metasurface provided in this embodiment polarization insensitivity, the metal part of the first layer in this embodiment has symmetry along both the x-axis and the y-axis.

[0064] Specifically, in order to enable the 1-bit sensing phase-modulation integrated reconfigurable intelligent metasurface provided in this embodiment, the LTC5530 chip is used as the above-mentioned detector chip.

[0065] The present embodiment provides a 1-bit sensing phase-modulation integrated reconfigurable intelligent metasurface that is insensitive to the incident angle and polarization direction. Under normal incidence of electromagnetic waves, the phase of the reflected wave of the electromagnetic wave incident on the present embodiment can be changed by changing the bias voltage on Pin tube 1. Specifically, for a 1-bit sensing phase-modulation integrated intelligent metasurface, two phase states with a phase interval of 180° should be obtained, and the incident wave can be sensed in both phase states.

[0066] The reflection amplitude and phase distribution of the two states are shown as Figure 5 and Figure 6 As shown. At 5.16 GHz, the reflection amplitude in both states is greater than -2 dB, and the phase interval is 180°. In the 5.12-5.2 GHz frequency band, the lowest reflection amplitude is -2.13 dB, the lowest phase interval is 169°, the maximum phase interval is 192°, and the phase fluctuation is less than 12°. Therefore, the present invention can achieve efficient reflection phase control in the 5.12-5.2 GHz frequency band.

[0067] The RF energy on the DC feeder and the RF energy on the sensing microstrip line in the two states are as follows: Figure 7 and Figure 8 As shown. At the center frequency of 5.16GHz, when the Pin tube is not turned on and turned on, the insertion loss on the DC feeder is -43dB and -39dB respectively, indicating that the DC feeder has a high ability to isolate RF signals. At the center frequency of 5.16GHz, when the Pin tube is not turned on and turned on, the insertion loss on the sensing microstrip line is -11dB and -9dB respectively, indicating that the sensing microstrip line has the ability to collect a small amount of RF energy; the minimum input power of the selected LTC5530 detector chip is -32dBm, so as long as the power of the electromagnetic wave incident on the present invention is greater than -21dBm, it can be detected and sensed by the detector chip.

[0068] Under TE polarization incident wave, the reflection amplitude and reflection phase interval of the two states change with the incident angle as shown in the figure below: Fig. 9 As shown in Figure 2, under TE polarization incident wave, the insertion loss of the sensing microstrip line and the insertion loss of the DC feeder in two states change with the incident angle. Fig.10 As shown. Under TM polarized incident wave, the curves of reflection amplitude and reflection phase interval of the two states as a function of incident angle are shown in Fig.11 As shown in Figure 2, under TM polarized incident wave, the insertion loss of the sensing microstrip line and the insertion loss of the DC feeder in two states change with the incident angle. Fig.12 As shown. Fig. 9 Fig.10It can be seen that when the incident angle is less than 45°, the reflection amplitude of the two phase states of the present invention under the incidence of TE polarized waves and TM polarized waves is greater than -3.5dB, and the reflection phase interval of the two states is in the range of 175-203°. Fig.11 Fig.12 It can be seen that when the incident angle is less than 45°, the insertion loss of the DC feeder under the incidence of TE polarized waves and TM polarized waves is less than -39dB, and the insertion loss of the sensing microstrip line is as low as -14dB. This shows that the present invention can have sensing and phase modulation performance under both normal incidence and oblique incidence, and can realize the integration of sensing and phase modulation.

[0069] It should be further noted that the unit provided in this embodiment operates at 5.12-5.2 GHz and is applied in the sub-6G band. If the unit size is adjusted, its operating frequency band can be flexibly adjusted and good sensing and phase modulation integration performance can be achieved.

[0070] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

[0071] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A polarization-insensitive sensing and phase-modulation integrated reconfigurable intelligent metasurface, characterized in that: The smart metasurface comprises: N×N basic units arranged periodically, wherein each basic unit is provided with different control signals by a control circuit; 1-bit reflection phase control of incident electromagnetic waves is performed, and 1-bit incoming wave sensing is performed at the same time, so as to realize the integration of sensing and phase modulation; the basic units comprise, from top to bottom: The first layer is a metal pattern layer (1) including a pin tube A (1.1), a pin tube B (1.2), a metal patch (1.3), an asymmetric slot (1.4), a thin metal strip A (1.5) and a thin metal strip B (1.6), wherein the two pin tubes are of the same model and are oriented perpendicularly to each other, the two thin metal strips are of the same size and are oriented perpendicularly to each other, and the two thin metal strips and the metal patch (1.5) are connected in series by the pin tube A and the pin tube B; The second layer is an upper dielectric substrate (2); The third layer is a metal layer (3); The fourth layer is an adhesive layer (4); The fifth layer is a lower dielectric substrate (5); The sixth layer is a feeder layer (6), the feeder layer comprising a sensing microstrip line (6.1) and a DC feeder (6.2), wherein the DC feeder (6.2) inputs a bias voltage to the Pin tube, and the sensing microstrip line (6.1) receives the energy signal of the incident wave for sensing; the DC feeder (6.2) is connected in series with an inductor (6.3) and a capacitor (6.4); one end of the capacitor (6.4) is connected to the DC feeder (6.2), and the other end is connected to the metal layer (3) via a blind hole (9); Among them, metal holes (7) are respectively arranged between the two thin metal strips in the first layer and the third layer, and the metal holes (7) all have DC bias and thus provide DC voltage for the Pin tube; a metal center through hole (8) is arranged between the metal patch (1.3) in the first layer and the sixth layer to provide DC bias and sense the energy of the incident wave.

2. The polarization-insensitive sensing and phase-modulation integrated reconfigurable intelligent metasurface according to claim 1, characterized in that: The Pin tube is in a conducting state when the bias voltage is 1V, and in a non-conducting state when the bias voltage is 0V; the internal equivalent circuits of the Pin tube in the conducting and non-conducting states are different, so that the incident Electromagnetic waves form different responses.

3. The polarization-insensitive sensing phase-modulation integrated reconfigurable intelligent metasurface according to claim 2, characterized in that: For the Pin tube, at a given frequency point, the phase interval of the electromagnetic wave back reflection of the Pin tube in the two states of conduction and non-conduction is 180°.

4. The polarization-insensitive sensing phase-modulation integrated reconfigurable intelligent metasurface according to claim 3, characterized in that: The Pin tube intelligently senses the energy of incident electromagnetic waves in both the conducting and non-conducting states; a small amount of incident electromagnetic wave energy is transmitted from the metal center through hole (8) to the sensing microstrip line (11), and then finally transmitted from the sensing microstrip line (11) to the detector chip (10).

5. The polarization-insensitive sensing phase-modulation integrated reconfigurable intelligent metasurface according to claim 4, characterized in that: The detector chip (10) converts the radio frequency signal on the sensing microstrip line (11) into an output voltage corresponding to the energy level of the radio frequency signal.

6. The polarization-insensitive sensing phase-modulation integrated reconfigurable intelligent metasurface according to claim 1, characterized in that: The size of the basic unit is P1=25.8mm, the size of the metal patch is P2=25.8mm, the long side of the depression of the metal patch is L1=3.4mm, the short side of the depression of the metal patch is L2=1.65mm, the line width of the thin metal strip is W=0.7mm, the size of the asymmetric slot is P3=1.05, the slot spacing is S=0.4mm, and the length of the thin metal strip is L3=2.18mm.

7. The polarization-insensitive sensing phase-modulation integrated reconfigurable intelligent metasurface according to claim 1, characterized in that: The thickness of the upper dielectric substrate is H1=3mm, the thickness of the bonding layer is H2=0.1mm, the thickness of the lower dielectric substrate is H3=1mm, the diameter of the metal center through hole is 0.6mm, and the diameters of the metal hole and the blind hole are 0.4mm.

Images