Phase coding metasurface structure based on electric control

Abstract

The invention relates to the technical field of artificial electromagnetic materials, and discloses an electric control-based phase coding metasurface structure, which comprises a top unit structure layer, a first dielectric substrate layer, a middle ground layer, a second dielectric substrate layer and a bottom bias layer which are sequentially arranged from top to bottom, and is characterized in that the top unit structure layer comprises two C-shaped metal patches; openings of the two metal patches are arranged back to back, a PIN diode is connected between the two metal patches, each metal patch is connected with the bottom bias layer through a metal via hole, and the bottom bias layer is externally connected with a voltage source. The electromagnetic response of the metasurface unit can be quickly and conveniently changed by adopting an electric control mode, the problem that once a traditional metasurface is designed and manufactured, the electromagnetic wave response and the electromagnetic function of the traditional metasurface are solidified, and the requirement of a complex electromagnetic system cannot be met is solved, a new thought is provided for intelligent metasurface design, and the intelligent metasurface can be widely applied to the field of intelligent metasurface design. And the requirement of intelligent components on high integration level in practice is met.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial electromagnetic materials, and in particular to a phase-encoded metasurface structure based on electrical control. Background Art

[0002] Metamaterials are artificial materials with extraordinary physical properties that natural materials do not have, which are composed of subwavelength artificial structures arranged in a periodic or quasi-periodic manner. They have attracted widespread attention in the fields of optics, electronics, physics, materials, etc. The properties of metamaterials are derived from finely designed artificial structures and can be customized as needed, providing a new design method and research paradigm for the design of artificial materials. As a two-dimensional metamaterial, the metasurface can modulate almost all the properties of electromagnetic waves, such as amplitude, phase, polarization mode and propagation mode, providing unprecedented freedom for manipulating electromagnetic waves. So far, a variety of functional metasurfaces have been proposed, such as plane reflectors, optically variable devices, microwave imagers, and optical components, which have great application potential.

[0003] However, these metasurfaces have a single function and cannot meet the requirements of high integration in practical applications, so some powerful multiplexed multifunctional metasurfaces have been constructed, usually through metasurface unit combination, anisotropic metasurface unit polarization multiplexing, dispersion wavelength multiplexing and other technologies to achieve multifunctional integration. However, since the electromagnetic function is pre-set, these metasurfaces are called static metasurfaces. The electromagnetic function of these static metasurfaces cannot be changed according to demand, which greatly limits their development in practical applications. Summary of the invention

[0004] The purpose of the present invention is to provide a phase-encoded metasurface structure based on electrical control, which can dynamically manipulate the electromagnetic response of electromagnetic waves by changing the working state of a PIN diode, and encode the metasurface to obtain different electromagnetic functions.

[0005] The technical solution of the present invention is:

[0006] A phase-encoding metasurface structure based on electric control comprises a top unit structure layer, a first dielectric substrate layer, an intermediate ground layer, a second dielectric substrate layer and a bottom bias layer which are sequentially arranged from top to bottom, wherein the top unit structure layer comprises two C-shaped metal patches, the openings of the two metal patches are arranged back to back, and a PIN diode is connected between the two metal patches, each of the metal patches is respectively connected to the bottom bias layer through a metal via, the bottom bias layer is externally connected to a voltage source, a voltage is applied to both ends of the PIN diode through the metal via, and a binary encoding process of 1 and 0 is realized on the metasurface by controlling the voltage applied to both ends of the PIN diode, the reflection state of each metasurface structure unit is controlled according to different coding sequences, the reflection phase generated by each unit is superimposed, and the electromagnetic wave is regulated to obtain different electromagnetic functions.

[0007] Preferably, as a further improvement of the present invention, the metal patch is of equal width structure, and the width of the metal patch satisfies the following relationship:

[0008] w3=0.2h1

[0009] Wherein, w3 is the width of the metal patch, and h1 is the thickness of the first dielectric substrate layer 1.

[0010] Preferably, as a further improvement of the present invention, the caliber of the opening of the metal patch satisfies the following relationship:

[0011]

[0012] In the formula, g is the diameter of the opening of the metal patch, and h1 is the thickness of the first dielectric substrate layer 1.

[0013] Preferably, as a further improvement of the present invention, the distance between the two metal patches satisfies the following relationship:

[0014] w2=0.6h1

[0015] Wherein, w2 is the distance between the two metal patches, and h1 is the thickness of the first dielectric substrate layer 1.

[0016] Preferably, as a further improvement of the present invention, the metal patch is plated on the first dielectric substrate layer using a printed circuit board process.

[0017] Preferably, as a further improvement of the present invention, the metal patch is made of metallic copper.

[0018] Preferably, as a further improvement of the present invention, the first dielectric substrate layer and the second dielectric substrate layer are both made of polytetrafluoroethylene, the first dielectric substrate layer is used to adjust the impedance of the metasurface unit, and the second dielectric substrate layer is used to isolate the middle ground layer and the bottom bias layer.

[0019] Preferably, as a further improvement of the present invention, the dielectric constants ε of the first dielectric substrate layer and the second dielectric substrate layer are r =2.65, loss tangent tanδ=0.001.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The PIN diode is completely embedded into the metasurface unit as a part to generate a phase difference of 180° to achieve 1-bit phase encoding. The controller outputs a voltage level sequence to change the working state of the PIN diode, that is, by loading a positive voltage across the PIN diode, a reflection phase is generated when the electromagnetic wave irradiates the metasurface unit, and the metasurface unit is encoded as "1". When no voltage is loaded across the PIN diode, another reflection phase is generated when the electromagnetic wave irradiates the metasurface unit, and the metasurface unit is encoded as "0". The difference between the two reflection phases is 180 degrees. M×N metasurface units are combined to form a metasurface structure. The same coding sequence controls the reflection state of each metasurface unit, and the reflection phase generated by each unit is superimposed, finally realizing the regulation of electromagnetic waves and obtaining different electromagnetic functions. Therefore, the use of electronic control can quickly and conveniently change the electromagnetic response of the metasurface unit, which is more in line with practical applications. It solves the problem that once the traditional metasurface is designed and manufactured, its electromagnetic wave response and electromagnetic function are solidified and cannot meet the needs of complex electromagnetic systems. It also provides a new idea for the design of intelligent metasurfaces, meets the requirements of high integration of intelligent components in practice, and has broad application prospects in health monitoring, 5G / 6G communications, smart sensors and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the three-dimensional structure of a phase-encoded metasurface structure based on electrical control according to an embodiment of the present invention.

[0023] Figure 2 A schematic top view and a schematic diagram of geometric parameters and dimensions of a phase-encoding metasurface structure based on electrical control according to an embodiment of the present invention.

[0024] Figure 3 It is a bottom-up schematic diagram and a schematic diagram of geometric parameters and dimensions of a phase-encoded metasurface structure based on electric control according to an embodiment of the present invention.

[0025] Figure 4A schematic side view and a schematic diagram of geometric parameters and dimensions of a phase-encoding metasurface structure based on electrical control according to an embodiment of the present invention.

[0026] Figure 5 Schematic diagram of simulated reflection phase of the electromagnetic response of the metasurface unit when the PIN diode of the present invention is in different working states.

[0027] Figure 6 Schematic diagram of simulated reflection amplitude of the electromagnetic response of the metasurface unit when the PIN diode of the present invention is in different working states.

[0028] Figure 7 It is a schematic diagram of simulation results of four different coding sequences of the present invention and the corresponding three-dimensional far-field scattering patterns and RCS curves. DETAILED DESCRIPTION

[0029] The following is combined with Figure 1 To the attached Figure 7 , the specific implementation methods of the present invention are described in detail. In the description of the invention, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0030] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the invention, unless otherwise specified, "plurality" means two or more.

[0031] Example

[0032] like Figures 1 to 4As shown, an embodiment of the present invention provides a phase-encoded metasurface structure based on electrical control, including a top unit structure layer 2, a first dielectric substrate layer 31, an intermediate ground layer 4, a second dielectric substrate layer 32 and a bottom bias layer 5 arranged in sequence from top to bottom, the top unit structure layer 2 includes two C-shaped metal patches, the openings of the two metal patches are arranged back to back, and a PIN diode 1 is connected between the two metal patches, each metal patch is connected to the bottom bias layer 5 through a metal via 6, the bottom bias layer 5 is externally connected to a voltage source, and a voltage is applied to both ends of the PIN diode 1 by using the metal via 6. By controlling the voltage applied to both ends of the PIN diode 1, a binary encoding process of 0 and 1 of the metasurface is realized, the reflection state of each metasurface structure unit is controlled according to different coding sequences, and the reflection phase generated by each unit is superimposed to realize the regulation of electromagnetic waves to obtain different electromagnetic functions.

[0033] In this embodiment, the PIN diode 1 is completely embedded into the metasurface unit as a part, and a 1-bit phase encoding is realized by using a metal patch with a C-shaped structure. By outputting a voltage level sequence by the controller and changing the working state of the PIN diode 1, the electromagnetic response of the electromagnetic wave can be dynamically manipulated, the metasurface can be encoded, and electromagnetic functions such as beam deflection and vortex beam can be realized, and the far-field scattering mode of the electromagnetic wave can be controlled;

[0034] When positive voltage is applied to both ends of PIN diode 1, a reflection phase will be generated when electromagnetic waves irradiate the metasurface unit, and the metasurface unit is encoded as "1". When no voltage is applied to both ends of PIN diode 1, another reflection phase will be generated when electromagnetic waves irradiate the metasurface unit, and the metasurface unit is encoded as "0". The difference between the two reflection phases is 180 degrees. M×N metasurface units are combined into a large metasurface, where M and N are both natural numbers. In practical applications, 30×30 metasurface units are combined into a metasurface structure. The reflection state of each metasurface unit is controlled according to different coding sequences, and the reflection phase generated by each unit is superimposed, so as to finally realize the regulation of electromagnetic waves and obtain different electromagnetic functions.

[0035] Therefore, the use of electronic control can quickly and easily change the electromagnetic response of the metasurface unit, which is more in line with practical applications. It solves the problem that once the traditional metasurface is designed and manufactured, its electromagnetic wave response and electromagnetic function are solidified and cannot meet the needs of complex electromagnetic systems. It also provides a new idea for the design of intelligent metasurfaces and meets the requirements of high integration of intelligent components in practice. It has broad application prospects in health monitoring, 5G / 6G communications, smart sensors and other fields.

[0036] Among them, PIN diode 1 is a SMP1340-011 PIN diode and adopts a SOD-323 package. In the ON state, PIN diode 1 is equivalent to a series circuit of a resistor of 1Ω and an inductor of 0.45nH, and in the OFF state, it is equivalent to a series circuit of a resistor of 10Ω, an inductor of 0.45nH and an inductor of 0.16pF.

[0037] According to the position and thickness of the metal via hole, holes are punched on the second dielectric substrate 32 to ensure that the metal via hole 6 passes through smoothly without being connected to the dielectric substrate.

[0038] Among them, the metal patch is a structure of equal width, and the width of the metal patch satisfies the following relationship:

[0039] w3=0.2h1

[0040] Wherein, w3 is the width of the metal patch, and h1 is the thickness of the first dielectric substrate layer 31 .

[0041] The opening of the metal patch satisfies the following relationship:

[0042]

[0043] In the formula, g is the diameter of the opening of the metal patch, and h1 is the thickness of the first dielectric substrate layer 31 .

[0044] Among them, the spacing between the two metal patches satisfies the following relationship:

[0045] w2=0.6h1

[0046] Wherein, w2 is the distance between the two metal patches, and h1 is the thickness of the first dielectric substrate layer 31 .

[0047] The metal patch is plated on the first dielectric substrate layer 31 using a printed circuit board process.

[0048] Among them, the material of the metal patch is metal copper.

[0049] The first dielectric substrate layer 31 and the second dielectric substrate layer 32 are both made of polytetrafluoroethylene. The first dielectric substrate layer 31 is used to adjust the impedance of the metasurface unit, and the second dielectric substrate layer 32 is used to isolate the middle ground layer 4 and the bottom bias layer 5 .

[0050] The dielectric constants ε of the first dielectric substrate layer 31 and the second dielectric substrate layer 32 are r =2.65, loss tangent tanδ=0.001.

[0051] Specifically, as an application example of the geometric parameters of the phase-encoding metasurface unit structure of the present invention, Figures 2 to 4As shown, the period of the super unit structure is p = 9 mm, the thickness of the first dielectric substrate layer 31 is h1 = 3.5 mm, the thickness of the second dielectric substrate layer 32 is h2 = 1 mm, the length of the C-shaped metal patch is l1 = 7 mm, the total width of the corner of the C-shaped metal patch is w1 = 1.7 mm, the width of the C-shaped metal patch is w3 = 0.7 mm, and the opening diameter of the C-shaped metal patch is g = 0.5 mm. The spacing between the two C-shaped metal patches is w2 = 2.1 mm. The diameter of the metal via 6 is d = 0.6 mm.

[0052] Furthermore, Figure 5 and Figure 6 The figure shows the simulation results of the electromagnetic response of the phase-encoded metasurface unit when the PIN diode 1 is in different working states. Figure 5 It can be seen from the figure that between the frequencies of 7.20 GHz and 7.44 GHz, the reflection phase of the metasurface unit achieves a phase difference of 180°±37°. Figure 6 It can be seen that the reflection amplitudes are almost equal and above 0.92, which meets the phase modulation condition and can achieve 1-bit phase encoding. The metasurface unit with PIN diode 1 in the on state is encoded as binary code "1", and the metasurface unit with PIN diode in the off state is encoded as binary code "0".

[0053] Furthermore, Figure 7 The following are the simulation results of four different coding sequences of the phase-coded metasurface and the corresponding three-dimensional far-field scattering patterns and RCS curves. Figure 7 (a) Figure 7 (b) Figure 7 (c) and Figure 7 As shown in (d), by encoding the metasurface according to different coding sequences, the deflection angle of the reflected electromagnetic wave beam can be changed, thereby realizing intelligent control of the electromagnetic wave, verifying the feasibility and effectiveness of the structure.

[0054] The above disclosures are only several preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A phase-encoded metasurface structure based on electrical control, characterized in that: The invention comprises a top unit structure layer (2), a first dielectric substrate layer (31), an intermediate ground layer (4), a second dielectric substrate layer (32) and a bottom bias layer (5) which are arranged in sequence from top to bottom. The top unit structure layer (2) comprises two C-shaped metal patches, the openings of the two metal patches are arranged back to back, a PIN diode (1) is connected between the two metal patches, each of the metal patches is connected to the bottom bias layer (5) via a metal via (6), the bottom bias layer (5) is externally connected to a voltage source, a voltage is applied to both ends of the PIN diode (1) via the metal via (6), and a binary encoding process of 0 and 1 is realized on the metasurface by controlling the voltage applied to both ends of the PIN diode (1), the reflection state of each metasurface structure unit is controlled according to different encoding sequences, the reflection phase generated by each unit is superimposed, and the electromagnetic wave is regulated to obtain different electromagnetic functions.

2. The electrically controlled phase-encoded metasurface structure according to claim 1, characterized in that: The metal patch is of equal width structure, and the width of the metal patch satisfies the following relationship: w3=0.2h1 In the formula, w3 is the width of the metal patch, and h1 is the thickness of the first dielectric substrate layer (31).

3. The electrically controlled phase-encoded metasurface structure according to claim 2, characterized in that: The opening of the metal patch satisfies the following relationship: In the formula, g is the diameter of the opening of the metal patch, and h1 is the thickness of the first dielectric substrate layer (31).

4. The electrically controlled phase-encoded metasurface structure according to claim 3, characterized in that: The spacing between the two metal patches satisfies the following relationship: w2=0.6h1 In the formula, w2 is the distance between the two metal patches, and h1 is the thickness of the first dielectric substrate layer (31).

5. The electrically controlled phase-encoded metasurface structure according to claim 1, characterized in that: The metal patch is plated on the first dielectric substrate layer (31) using a printed circuit board process.

6. The electrically controlled phase-encoded metasurface structure according to claim 1, characterized in that: The material of the metal patch is metal copper.

7. The electrically controlled phase-encoded metasurface structure according to any one of claims 4 to 6, characterized in that: The first dielectric substrate layer (31) and the second dielectric substrate layer (32) are both made of polytetrafluoroethylene; the first dielectric substrate layer (31) is used to adjust the impedance of the metasurface unit; and the second dielectric substrate layer (32) is used to isolate the middle ground layer (4) and the bottom bias layer (5).

8. The electrically controlled phase-encoded metasurface structure according to claim 7, characterized in that: The dielectric constant ε of the first dielectric substrate layer (31) and the second dielectric substrate layer (32) is r =2.65, loss tangent tanδ=0.001.

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