A wave beam collimator based on angular domain dispersion metasurface

Abstract

The present application relates to a kind of based on angular dispersion super surface wave beam collimator, it is related to microwave frequency band electromagnetic wave control field, including: multiple angular dispersion units in array form periodically arranged;The angular dispersion unit includes metal pattern layer and two parallelly arranged dielectric substrates;The metal pattern layer includes two first metal pattern layers and a second metal pattern layer;Two the first metal pattern layer is symmetrically arranged outside two the dielectric substrate, one first metal pattern layer corresponds one the dielectric substrate;The second metal pattern layer is arranged between two the dielectric substrate.The wave beam collimator provided in the present application realizes collimation exit to ±45° and 0° incident electromagnetic wave.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microwave frequency electromagnetic wave regulation, in particular to a wave beam collimator based on an angular domain dispersion super surface. BACKGROUND

[0002] The super surface is a two-dimensional sub-wavelength unit array super thin artificial structure, and the super surface can regulate the polarization, amplitude and phase of the incident electromagnetic wave in the sub-wavelength scale by properly regulating the geometric parameters of the basic unit and changing the arrangement mode of the basic unit, so as to realize various electromagnetic wave front regulation functions. The emergence of the super surface has attracted more and more attention of scientific researchers, and the application based on the super surface involves multiple fields, especially in the phase modulation field. By reasonably designing the phase response distribution of the super surface structure, the incident electromagnetic wave can be reflected and focused.

[0003] Collimation refers to the straight transmission of electromagnetic waves along a certain direction without diffraction, and the beam width remains unchanged, and the adjacent light rays are parallel. For non-collimated transmission of electromagnetic waves, the divergence degree of the beam will gradually increase with the increase of the transmission distance. When the receiving end aperture size is fixed, it is difficult to accept all the transmission energy, which greatly reduces the energy transmission and reception efficiency. Therefore, the beam collimation of electromagnetic waves is a current research hotspot.

[0004] At present, the beam collimation of electromagnetic waves is mainly realized based on super surface structure devices or self-collimation effect devices. In recent years, the realized beam collimation super surface generally targets a certain specific beam incident in a specific direction, and cannot meet the collimation effect of beams incident in any direction. Although the self-collimation effect device can realize wideband full-angle beam self-collimation, after the beam passes through the interface of the crystal, the beam will continue to propagate along its original direction, and the transmission direction does not change, so the beam collimation outside the crystal structure cannot be realized. It is of great significance to improve the transmission and reception efficiency of energy to realize the collimated transmission of electromagnetic waves incident in multiple angles. SUMMARY

[0005] The purpose of the present application is to provide a wave beam collimator based on an angular domain dispersion super surface, which realizes collimated emission of ±45° and 0° incident electromagnetic waves.

[0006] To achieve the above purpose, the present application provides the following scheme:

[0007] A wave beam collimator based on an angular domain dispersion super surface, comprising: a plurality of angular domain dispersion units arranged in an array form in a periodic manner;

[0008] The angular dispersion unit comprises a metal pattern layer and two parallel arranged dielectric substrates; the metal pattern layer comprises two first metal pattern layers and one second metal pattern layer; the two first metal pattern layers are symmetrically arranged outside the two dielectric substrates, and one first metal pattern layer corresponds to one dielectric substrate; the second metal pattern layer is arranged between the two dielectric substrates.

[0009] Optionally, the first metal pattern layer is an electrically coupled metal pattern layer; the electrically coupled metal pattern layer comprises two parallel strips and two vertical strips.

[0010] The two parallel strips are parallel to each other; the two vertical strips are perpendicular to the two parallel strips; the midpoint of each parallel strip is connected to one end of the vertical strip; the two vertical strips are located on the same straight line and are arranged on the two sides of the two parallel strips.

[0011] Optionally, the second metal pattern layer is a Jerusalem cross metal pattern layer; the Jerusalem cross metal pattern layer comprises a first branch, a second branch and four third branches; the first branch and the second branch are perpendicular to each other; the midpoint of the first branch is connected to the midpoint of the second branch; the length of the first branch is greater than or equal to the length of the second branch; the third branch is arranged at the end point of the first branch and the second branch; the third branch is perpendicular to the first branch or the second branch connected with the third branch; the first branch is parallel to the -45° incident direction of the electromagnetic wave.

[0012] Optionally, the material of the metal pattern layer is copper.

[0013] Optionally, the dielectric constant of the material of the dielectric substrate is 10.2; and the loss tangent of the material of the dielectric substrate is 0.0023.

[0014] Optionally, the shape of the dielectric substrate is a cuboid.

[0015] Optionally, the angular dispersion unit is arranged on the xoz plane; and the angular dispersion units are periodically arranged along the x direction and the y direction.

[0016] Optionally, the number of the angular dispersion units in one period in the x direction is 9, and the number of the angular dispersion units in one period in the y direction is 1.

[0017] According to the specific embodiments of the present application, the following technical effects are provided.

[0018] The application provides a wave beam collimator based on an angular dispersion super surface, which comprises a plurality of angular dispersion units arranged in an array form in a periodical mode; the angular dispersion unit comprises a metal pattern layer and two dielectric substrates; the metal pattern layer comprises two first metal pattern layers and one second metal pattern layer; the two first metal pattern layers are symmetrically arranged outside the two dielectric substrates, and one first metal pattern layer corresponds to one dielectric substrate; and the second metal pattern layer is arranged between the two dielectric substrates. The wave beam collimator based on the angular dispersion super surface can collimate incident electromagnetic waves at ±45° and 0°. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 A three-dimensional structure schematic diagram of the wave beam collimator based on the angular dispersion super surface is provided.

[0021] Figure 2 A three-dimensional schematic diagram of the angular dispersion unit is provided.

[0022] Figure 3 A schematic diagram of the first metal pattern layer is provided.

[0023] Figure 4 A schematic diagram of the second metal pattern layer is provided.

[0024] Figure 5 Transmission phase distribution diagrams and transmission amplitude distribution diagrams of each unit structure under the condition of electromagnetic wave-45° incidence are provided.

[0025] Figure 6 Transmission phase distribution diagrams and transmission amplitude distribution diagrams of each unit structure under the condition of electromagnetic wave+45° incidence are provided.

[0026] Figure 7 Transmission phase distribution diagrams and transmission amplitude distribution diagrams of each unit structure under the condition of electromagnetic wave 0° incidence are provided.

[0027] Figure 8 Transmission electromagnetic wave phase distribution diagrams and field intensity distribution diagrams of the embodiments of the present application under the condition of electromagnetic wave-45° incidence are provided.

[0028] Figure 9The phase distribution diagram and field strength distribution diagram of the transmitted electromagnetic wave obtained by simulation under the condition of +45° electromagnetic wave incidence in the embodiments provided by the present invention;

[0029] Figure 10 The embodiments provided by the present invention simulate the phase distribution and field strength distribution of transmitted electromagnetic waves under the condition of 0° electromagnetic wave incidence.

[0030] Symbol explanation:

[0031] 1-Dielectric substrate, 2-Metal pattern layer. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The purpose of this invention is to provide a beam collimator based on an angular domain dispersive metasurface, which can achieve collimated output of electromagnetic waves incident at ±45° and 0°.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] like Figure 1 As shown, the present invention provides a beam collimator based on an angular domain dispersive metasurface, comprising: a plurality of angular domain dispersive units arranged periodically in an array; wherein the angular domain dispersive units are as follows: Figure 2 As shown, Figure 2 The layers in the structure are parallel to the xoz plane; the angular domain dispersive unit is an asymmetric Huygens metasurface unit structure. The use of asymmetric Huygens units enables antisymmetric phase changes with respect to the 0° incident direction of the electromagnetic wave and achieves high transmission efficiency. The angular domain dispersive units are arranged continuously and periodically in both the x and y directions. Each angular domain dispersive unit has the same structure, with only the size parameters of the metal pattern layer 2 changing. Units with different sizes exhibit different phase responses to the incident electromagnetic wave, allowing for manipulation of the wavefront.

[0036] The angular dispersion unit comprises a metal pattern layer 2 and two parallel arranged dielectric substrates 1; the metal pattern layer 2 comprises two first metal pattern layers and one second metal pattern layer; two first metal pattern layers are symmetrically arranged outside two dielectric substrates 1, one first metal pattern layer corresponds to one dielectric substrate 1; the second metal pattern layer is arranged between two dielectric substrates 1. The size of the two layers of dielectric substrates 1 is the same.

[0037] In practical application, the first metal pattern layer is an electrically coupled (Electric field coupled, ELC) metal pattern layer; two ELC metal pattern layers are completely the same and located on both sides of the unit, and the structure is as shown in Figure 3 The electrically coupled metal pattern layer comprises two parallel strips and two vertical strips.

[0038] The two parallel strips are parallel to each other; the two vertical strips are perpendicular to the two parallel strips; the midpoint of each parallel strip is connected to one end of the vertical strip; the two vertical strips are located on the same straight line and arranged on both sides of the two parallel strips.

[0039] In practical application, as shown in Figure 4 The second metal pattern layer is a Jerusalem cross (Jerusalem cross, JC) metal pattern layer; the Jerusalem cross metal pattern layer comprises a first branch, a second branch and four third branches; the first branch and the second branch are perpendicular to each other; the midpoint of the first branch is connected to the midpoint of the second branch; the length of the first branch is greater than or equal to the length of the second branch; the third branch is arranged at the end point of the first branch and the second branch; the third branch is perpendicular to the first branch or the second branch connected with the third branch; the first branch is parallel to the electromagnetic wave-45° incident direction. The metal pattern layer 2 comprises two identical ELC metal pattern layers symmetrically placed outside the two layers of dielectric substrates 1, and the JC metal pattern layer is placed between the two layers of dielectric substrates 1.

[0040] In practical application, the material of the metal pattern layer 2 is copper, and the electrical conductivity is 5.88×10 7 s / m. The dielectric constant of the material of the dielectric substrate 1 is 10.2; the loss tangent of the dielectric substrate 1 is 0.0023. The shape of the dielectric substrate 1 is a rectangular parallelepiped, the length is dx, the height is h, and the thickness is t.

[0041] The angular dispersion unit is arranged on the xoz plane; the angular dispersion unit is periodically arranged along the x direction and the y direction. The number of the angular dispersion units in one period in the x direction is 9, and the number of the angular dispersion units in one period in the y direction is 1. The structures of the plurality of super surface units and the size of the dielectric substrate 1 are the same, and only the size parameters of the ELC and the JC change. The plurality of units are periodically and continuously arranged. In the x axis, 9 units are one period, the arrangement order of the units in each period is the same, and the center distance between adjacent units is 4.71 mm; in the y direction, 1 unit is one period, and the structure and size of each unit are the same, and the center distance between adjacent units is 3.5 mm. In the x direction and the y direction, any integer number of periods can be formed.

[0042] When electromagnetic waves irradiate the device, each unit on it will produce a phase jump to the incident electromagnetic waves, and the periodically arranged super surface units produce a periodically changed phase jump, which point-by-point modulates the phase of the transmitted electromagnetic waves, so that the phase response of the transmitted electromagnetic waves at each unit is approximately consistent, thereby realizing the beam collimation function of the transmitted electromagnetic waves along the normal direction of the super surface. The unit has different phase responses under different angle of incidence, and the phase response of the unit and the angle of incidence are almost linear and anti-symmetrical about the 0° incidence direction of electromagnetic waves.

[0043] The JC metal pattern layer has two branch lengths that are inconsistent in length, the length L1 of the third branch connected with the first branch, the length L2 of the third branch connected with the second branch, the sum H1 of the length of the first branch and the width of the two third branches, the sum H2 of the length of the second branch and the width of the two third branches, and the parallel strip length C1 of the ELC metal structure layer. Electromagnetic waves are incident from -45°, +45° and 0° respectively, and the working frequency is 10 GHz. Different phase responses can be achieved under different angle of incidence. By changing the size parameters of the metal pattern layer 2, the phase response of the unit to the transmitted electromagnetic waves can be adjusted, and the phase responses of different size units can cover the phase change of 0-2π and have good transmission efficiency. The beam collimator based on the angular dispersion super surface proposed in the application can achieve the collimation effect of the electromagnetic waves incident at ±45° and 0° after being transmitted through the collimator, and can simultaneously realize the collimation transmission of the electromagnetic waves incident at three angles, which has important significance for improving the transmission and reception efficiency of energy.

[0044] As Figure 1As shown, the wave beam collimator based on the angular dispersion super surface provided by the application is composed of 4 periods in the x direction and 19 periods in the y direction. Taking the working frequency of 10 GHz as an example, the overall width of the unit is dx = 4.71 mm, the height is h = 4.71 mm, the thickness is t = 0.635 mm, the thickness of the metal pattern layer is t1 = 0.017 mm, the line width of the metal pattern layer is w1 = 0.2 mm, and the gap of the ELC metal pattern layer is g = 0.2 mm. These parameters are fixed parameters and are the same on each unit.

[0045] The incident angle is ± θ i The beam is vertically emitted through the super surface, satisfying the generalized Snell's law:

[0046]

[0047] λ0 is the wavelength of the free space electromagnetic wave corresponding to the working frequency, dΦ is the phase response change amount of the adjacent unit transmission electromagnetic wave, the incident angles of the electromagnetic waves of 0, +45° and -45° are realized through the super surface, that is, θ t = 0°, and the above formula can be written as:

[0048]

[0049] Substituting dx = 4.71 mm into the formula, the phase response change amount dΦ of the adjacent unit required for the beam to be vertically emitted after passing through the super surface under the conditions of +45°, 0° and -45° incidence is -40°, 0° and 40° respectively. The 2π period change of the phase requires 9 units of different sizes in the x direction.

[0050] Taking the unit at x = 0 as the reference unit, the phase response of each unit needs to satisfy:

[0051]

[0052] Let Φ0 = 0°, in order to realize the beam collimation emission, the phase required by the unit at the coordinate (x, y) is where θ i = 0°, +45°, -45°.

[0053] As shown in Table 1, the lengths L1, L2, H1 and H2 of the two branches of the JC metal pattern layer and the length C1 of the parallel strip of the ELC metal pattern layer are changed as control parameters, so that the transmission phase and transmission amplitude of each transmission unit are changed, as shown in Table 1. Figures 5-7

[0054] Table 1, the metal pattern layer size parameters of each unit structure in one period in the x direction

[0055] ​

[0056] Figures 5-7 The transmission phase and transmission amplitude distribution diagrams of each unit structure of the application under the conditions of electromagnetic wave-45°, +45° and 0° incidence, and the working frequency is 10GHz. The transmission phase of each unit changes linearly and the transmission phase range meets the requirement of 2π phase shift, at the same time, the insertion loss of each unit is less than 4dB, and it has high transmissivity characteristics.

[0057] The above results are obtained by simulation calculation with the help of electromagnetic simulation software, using Floquet port as excitation and master-slave boundary as boundary condition. The unit is a transmission type unit, the incident wave is transmitted from the upper surface to the lower surface, and the unit has master-slave boundary on both sides in x direction and y direction.

[0058] Figures 8-10 The transmission electromagnetic wave phase distribution diagram and field intensity distribution diagram of the embodiment of the application under the conditions of electromagnetic wave along-45°, +45° and 0° are shown in Figures 1-3, and the working frequency is 10GHz. Figure 8 The transmission electromagnetic wave phase distribution diagram of the embodiment of the application under the conditions of electromagnetic wave along-45° is shown in Figure 1(a), Figure 8 The transmission electromagnetic wave field intensity distribution diagram of the embodiment of the application under the conditions of electromagnetic wave along-45° is shown in Figure 1(b), Figure 9 The transmission electromagnetic wave phase distribution diagram of the embodiment of the application under the conditions of electromagnetic wave along+45° is shown in Figure 2(a), Figure 9 The transmission electromagnetic wave field intensity distribution diagram of the embodiment of the application under the conditions of electromagnetic wave along+45° is shown in Figure 2(b), Figure 10 The transmission electromagnetic wave phase distribution diagram of the embodiment of the application under the conditions of electromagnetic wave along 0° is shown in Figure 3(a), Figure 10 The transmission electromagnetic wave field intensity distribution diagram of the embodiment of the application under the conditions of electromagnetic wave along 0° is shown in Figure 3(b), Figures 8-10 It can be clearly seen that under the conditions of electromagnetic wave along-45°, +45° and 0°, the beam realizes the expected collimation effect after the collimator.

[0059] The application provides a wave beam collimator based on an angular dispersion super surface, which is used for realizing collimation of multiple angle incident electromagnetic waves and belongs to the technical field of microwave frequency electromagnetic wave regulation. The artificial electromagnetic super surface is composed of multiple angular dispersion units, the units are arranged periodically, and the wave front of the incident electromagnetic wave is manipulated. The unit comprises: two layers of dielectric substrates arranged in parallel; two identical electrically coupled metal pattern layers symmetrically arranged outside the two layers of dielectric substrates; and a Jerusalem cross metal pattern layer arranged between the two layers of dielectric substrates. The multiple angular dispersion units are arranged periodically and continuously, the structure and the size of the dielectric substrate are the same, and only the size parameter of the metal pattern layer changes. The application scheme utilizes the characteristic that the angular dispersion super surface unit has a transmission phase which is antisymmetric about the 0° incident direction of the electromagnetic wave, so that the plane electromagnetic waves with ±45° and 0° incidence can realize the expected beam collimation effect after passing through the wave beam collimator based on the angular dispersion super surface designed by the application.

[0060] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments.

[0061] The principles and implementation modes of the application are described by using specific examples in the specification, and the above description of the embodiments is only used to help understand the method of the application and its core idea; meanwhile, for those skilled in the art, the specific implementation modes and application ranges can be changed according to the idea of the application. In summary, the content of the specification should not be understood as a limitation of the application.

Claims

1. A beam collimator based on an angular domain dispersive metasurface, characterized in that, include: Multiple angular domain dispersive units arranged periodically in an array; The angular dispersion unit includes a metal patterned layer and two parallel dielectric substrates; the metal patterned layer includes two first metal patterned layers and one second metal patterned layer; the two first metal patterned layers are symmetrically disposed on the outside of the two dielectric substrates, with one first metal patterned layer corresponding to one dielectric substrate; the second metal patterned layer is disposed between the two dielectric substrates. The first metal pattern layer is an electrically coupled metal pattern layer; the electrically coupled metal pattern layer includes two parallel stripes and two vertical stripes; The two parallel strips are parallel to each other; the two vertical strips are perpendicular to the two parallel strips; the midpoint of each parallel strip is connected to one end of a vertical strip; the two vertical strips are located on the same straight line and are arranged on both sides of the two parallel strips. The second metal pattern layer is a Jerusalem cross metal pattern layer; the Jerusalem cross metal pattern layer includes a first branch, a second branch, and four third branches; the first branch and the second branch are perpendicular to each other; the midpoint of the first branch is connected to the midpoint of the second branch; the length of the first branch is greater than or equal to the length of the second branch; the third branch is provided at the endpoints of both the first and second branches; the third branch is perpendicular to the first or second branch connected to the third branch; the first branch is parallel to the -45° incident direction of the electromagnetic wave; Each angular domain dispersive unit has a different phase response under electromagnetic wave incident at different angles; each angular domain dispersive unit has the same structure, only the size parameter of the metal pattern layer changes, and structural units with different sizes have different phase responses to incident electromagnetic waves, which is used to realize the manipulation of the wavefront of incident electromagnetic waves. Electromagnetic waves are incident from -45°, +45° and 0° respectively, and different phase responses can be achieved under different incident angles. The phase response of the electromagnetic waves transmitted by the unit can be adjusted by changing the size parameters of the metal pattern layer, and the phase response of the unit with different size can cover the phase change from 0 to 2π. The above-mentioned angular domain dispersive units are arranged periodically in an array form, which can simultaneously realize the collimated transmission of electromagnetic waves incident at three angles of 0°, +45° and -45°.

2. The beam collimator based on an angular domain dispersive metasurface according to claim 1, characterized in that, The material of the metal pattern layer is copper.

3. The beam collimator based on an angular domain dispersive metasurface according to claim 1, characterized in that, The dielectric constant of the dielectric substrate is 10.2; the loss tangent of the dielectric substrate is 0.0023.

4. The beam collimator based on an angular domain dispersive metasurface according to claim 1, characterized in that, The dielectric substrate is rectangular in shape.

5. The beam collimator based on an angular domain dispersive metasurface according to claim 1, characterized in that, The angular domain dispersion unit is disposed on the xoz plane; the angular domain dispersion unit is periodically arranged along the x and y directions.

6. The beam collimator based on an angular domain dispersive metasurface according to claim 5, characterized in that, The number of angular domain dispersive units per period in the x-direction is 9, and the number of angular domain dispersive units per period in the y-direction is 1.

Images