CN110661106A - Cross-polarized vortex beam lens based on frequency selective surface - Google Patents

Cross-polarized vortex beam lens based on frequency selective surface Download PDF

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Publication number
CN110661106A
CN110661106A CN201910941273.9A CN201910941273A CN110661106A CN 110661106 A CN110661106 A CN 110661106A CN 201910941273 A CN201910941273 A CN 201910941273A CN 110661106 A CN110661106 A CN 110661106A
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China
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frequency selective
selective surface
vortex beam
rectangular
beam lens
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张狂
王禹翔
姚瑶
陆满君
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Harbin Institute of Technology
Shanghai Radio Equipment Research Institute
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Harbin Institute of Technology
Shanghai Radio Equipment Research Institute
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/02—Refracting or diffracting devices, e.g. lens, prism
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/0006—Devices acting selectively as reflecting surface, as diffracting or as refracting device, e.g. frequency filtering or angular spatial filtering devices
    • H01Q15/0013—Devices acting selectively as reflecting surface, as diffracting or as refracting device, e.g. frequency filtering or angular spatial filtering devices said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective
    • H01Q15/0026—Devices acting selectively as reflecting surface, as diffracting or as refracting device, e.g. frequency filtering or angular spatial filtering devices said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective said selective devices having a stacked geometry or having multiple layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/24—Polarising devices; Polarisation filters 
    • H01Q15/242—Polarisation converters

Abstract

Cross polarization vortex beam lens based on frequency selective surface relates to the electromagnetic wave field, in order to solve the problem that current vortex beam lens receives the thickness restriction. The frequency selection surface unit comprises a metal layer and 2 dielectric layers; the metal layers and the dielectric layers are mutually parallel, stacked and staggered, the metal layers at the top and the bottom are rectangular patches I, the metal layer in the middle comprises a square patch and a rectangular patch II, a circular groove is formed in the center of the square patch, and the rectangular patch II is positioned in the circular groove; the rotation angle of each frequency selective surface unit is theta,
Figure DDA0002222966100000011
wherein l is the number of orbital angular movements, and x and y are the x-axis and y-axis coordinates of the frequency selective surface unit, respectivelyThe frequency selective surface rotates clockwise when l is positive and counterclockwise when l is negative. The invention is suitable for generating vortex beams carrying orbital angular momentum in any mode.

Description

Cross-polarized vortex beam lens based on frequency selective surface
Technical Field
The invention relates to the field of electromagnetic waves, in particular to a phase discontinuous extraordinary lens.
Background
With the rapid development of wireless communications, the spectral efficiency and channel capacity of communication links have approached the shannon limit. Although higher order modulation techniques and coding methods can improve spectral efficiency, their effectiveness is limited. Orbital angular momentum, which represents the rotation of electrons about a propagation axis, is generated by the rotation of energy flow about an optical axis, which causes the phase front of an electromagnetic wave to swirl. Therefore, an electromagnetic wave carrying orbital angular momentum is also called a vortex electromagnetic wave. The vortex beam uses the topological charge number as a modulation parameter, and the orthogonality among different modes is utilized, so that the information on each channel cannot influence each other. Theoretically, infinite vortex beams can be obtained in the same frequency band by using the method, so that the capacity of a channel is greatly improved. The antenna array, the most common radiating element in the low frequency region, can produce single or multiple orbital angular momentum modes. However, since a specific phase difference needs to be generated between the array elements, a complex feeding network is required, which is a great problem. Spiral phase plates are typically used in the optical band to create vortex beams that use thickness differences at different azimuthal angles to introduce different transmission phases. The thickness of the helical phase plate does not pose a limitation in its practical application due to the short wavelength. However, in the microwave and millimeter wave bands, the wavelength is long, and when the number of orbital angular momentum states is large, the thickness of the helical phase plate and the weight limit caused by the thickness are huge.
Disclosure of Invention
The invention aims to solve the problem that the existing vortex beam lens is limited by thickness, and therefore the cross-polarization vortex beam lens based on the frequency selection surface is provided.
The cross polarization vortex beam lens based on the frequency selective surface comprises a plurality of frequency selective surface units which are arranged in an array manner;
the frequency selection surface unit comprises 3 metal layers and 2 dielectric layers 1;
the metal layers and the dielectric layers 1 are mutually parallel, stacked and staggered, the metal layers at the top and the bottom are rectangular patches I2, the metal layer in the middle comprises square patches 3 and rectangular patches II 4, a circular groove is formed in the center of each square patch 3, and each rectangular patch II 4 is positioned in the corresponding circular groove;
establishing a space rectangular coordinate system by taking the center of the lens as an origin, one side of the lens as an x-axis and the adjacent side as a y-axis;
the rotation angle of each frequency selective surface unit is theta,
Figure BDA0002222966080000011
wherein l is the number of orbital angular movements, x and y are the x-axis and y-axis coordinates of the frequency selective surface unit, respectively, the frequency selective surface rotating in a clockwise direction when l is a positive number, and the frequency selective surface rotating in a counterclockwise direction when l is a negative number.
Preferably, the rectangular patch one 2 has a length L1 of 7.5mm and a width W1 of 4mm, the rectangular patch two 4 has a length L2 of 7mm and a width W2 of 3mm, and the circular groove has a radius R of 4 mm.
Preferably, the frequency selective surface elements are square with a side length D of 10 mm.
Preferably, the dielectric layer 1 has a relative dielectric constant of 3 and a thickness of 1 mm.
According to the invention, phase difference is introduced in the x and y directions through the first rectangular patch, resonance is formed through the square patch and the rectangular patch, the thickness of the unit is reduced, and the transmission coefficient of the unit has extremely high stability when the unit rotates; when circularly polarized electromagnetic waves are incident, the cross polarization component in the transmission electromagnetic field carries orbital angular momentum of any mode. The number of orbital angular momentum of the invention does not depend on the thickness, and the invention has the advantages of ultra-thin and high efficiency.
Drawings
FIG. 1 is a perspective view of a frequency selective surface element after the layers have been separated;
FIG. 2 is a top view of a frequency selective surface unit;
FIG. 3 is a schematic diagram of the structure of the metal layer in the middle;
FIG. 4 is a graph of transmission coefficients and transmission phase of cross-polarized components when a frequency selective surface element is rotated at different angles;
(a) transmission coefficient, (b) transmission phase;
FIG. 5 is a schematic diagram of a cross-polarized vortex beam lens based on a frequency selective surface;
FIG. 6 is a measurement of cross-polarized vortex beam lenses based on frequency selective surfaces at 10GHz, 10.7GHz and 11 GHz;
FIG. 7 is a graph of vortex beam efficiency for testing and simulation;
FIG. 8 is a graph of the purity of orbital angular momentum modes carried by a transmitted electromagnetic wave for testing and simulation.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.
The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.
The cross-polarized vortex beam lens based on the frequency selective surface comprises a plurality of frequency selective surface units which are arranged in an array manner;
the frequency selection surface unit comprises 3 metal layers and 2 dielectric layers 1;
the metal layers and the dielectric layers 1 are mutually parallel, stacked and staggered, the metal layers at the top and the bottom are rectangular patches I2, the metal layer in the middle comprises square patches 3 and rectangular patches II 4, a circular groove is formed in the center of each square patch 3, and each rectangular patch II 4 is positioned in the corresponding circular groove;
each frequency selective surface element rotates along the x-axis according to its azimuth angle by an angle θ:
Figure BDA0002222966080000031
wherein l is the number of orbital angular movements, x and y are the x-axis and y-axis coordinates of the frequency selective surface unit with the center of the lens as the origin, respectively, the frequency selective surface rotating in a clockwise direction when l is a positive number, and the frequency selective surface rotating in a counterclockwise direction when l is a negative number. The solution method of the azimuth angle comprises the following steps: firstly, connecting a line between the central coordinate of the frequency selection surface and an original point, and then solving an included angle between the line and the positive direction of the x axis, wherein the included angle is an azimuth angle.
In this embodiment, the length L1 of the rectangular patch one 2 is 7.5mm, the width W1 is 4mm, the length L2 of the rectangular patch two 4 is 7mm, the width W2 is 3mm, and the radius R of the circular groove is 4 mm; the frequency selection surface unit is square, and the side length D is 10 mm; the dielectric layer 1 had a relative dielectric constant of 3 and a thickness of 1 mm.
The principle of the invention is as follows:
for circularly polarized incident waves propagating in the Z direction, the electric field can be decomposed into two orthogonal components, taking left-handed circularly polarized waves as an example:
Figure BDA0002222966080000032
wherein
Figure BDA0002222966080000033
Is the electric field of the incident electromagnetic wave,
Figure BDA0002222966080000034
andtwo components, E, in the x and y directions, respectively0Is the magnitude of the electric field and,
Figure BDA0002222966080000036
and
Figure BDA0002222966080000037
the phases in the x and y directions, respectively, and k is the propagation constant. In order to convert a circularly polarized wave into its cross-polarized wave, it is necessary that the cell be able to respond to the electromagnetic components in these two directions separately:
Figure BDA0002222966080000038
wherein the content of the first and second substances,
Figure BDA0002222966080000039
for transmitted electromagnetic wave electric field, T is the total transmission coefficient, TxAnd TyTransmission coefficients in the x and y directions, respectively; in the ideal case, | T | ═ Tx|＝|TyThis means that the unit has the same transmission efficiency for both directions without any loss; furthermore, cross-polarization transmission coefficients are considered negligible;
Figure BDA00022229660800000310
and
Figure BDA00022229660800000311
the phase differences in the x and y directions that the cell generates for the electromagnetic wave, respectively. Therefore, the total phase difference of the electromagnetic waves in the vertical and horizontal directions is:
Figure BDA0002222966080000041
because the left-hand circularly polarized wave has a phase difference of 90 degrees in the x direction and the y direction, the unit can convert the left-hand circularly polarized wave into the right-hand circularly polarized wave only by introducing a phase difference of 180 degrees.
For vertically incident circularly polarized electromagnetic waves, the frequency selective surface unit of the embodiment can efficiently convert the circularly polarized electromagnetic waves into the cross-polarized circularly polarized waves, and when the unit rotates, the transmission coefficient has high stability, and the phase difference and the rotation angle have a relationship of 2 times, namely, a Pancharatnam-Berry phase is introduced, as shown in fig. 4, the transmission coefficient of the cross-polarized waves in the range from 10.2GHz to 11.2GHz is maintained to be more than 0.8 in the gray area.
Based on the vortex beam lens with the above unit structure, the patches in each metal layer of the lens need to rotate according to the respective azimuth angles, and the rotation angle is θ and is expressed as:
Figure BDA0002222966080000042
where l is the number of orbital angular motion, i.e., the number of topological charges, and in this embodiment, l is 2. The vortex lens is composed of 35 × 35 elements, and the transmitted right-hand circularly polarized wave will carry orbital angular momentum of mode number 2 at the incidence of the left-hand circularly polarized plane wave.
Fig. 6 is a measurement result of the vortex beam lens at 10GHz, 10.7GHz, and 11GHz, where (a) - (f) are test results of xoy plane at z 100mm, (a) - (c) are phases of electromagnetic waves, it can be seen that the phase of transmitted wave has double helix gradient, (d) - (f) are amplitudes of electromagnetic waves, it can be seen that the electromagnetic wave energy has a characteristic of circular distribution, and the energy of the central region is 0, (g) - (i) are test results of xoz plane at y 0, the energy of electromagnetic wave is zero at the center of the propagation direction, and the energy distribution is uniform on both sides. (a) (d) and (g) are 10GHz, (b), (e) and (h) are 10.7GHz, and (c), (f) and (i) are 11 GHz.
FIG. 7 is the vortex beam efficiency tested and simulated, up to 85% at 10.7GHz and greater than 50% in the 10GHz-11.1GHz range.
Fig. 8 is a spectral analysis of the orbital angular momentum mode carried by the transmitted electromagnetic waves for testing and simulation, where the purity of mode 2 is close to 100% in simulation and 93.4% in test, which is mainly due to the manufacturing accuracy. The lens can effectively excite the vortex beam with the mode number of 2.

Claims (4)

1. The cross-polarized vortex beam lens based on the frequency selective surface is characterized by comprising a plurality of frequency selective surface units arranged in an array manner;
the frequency selection surface unit comprises 3 metal layers and 2 dielectric layers (1);
the metal layers and the dielectric layers (1) are mutually parallel, stacked and staggered, the metal layers at the top and the bottom are rectangular patches I (2), the metal layer in the middle comprises square patches (3) and rectangular patches II (4), a circular groove is formed in the center of each square patch (3), and each rectangular patch II (4) is located in the circular groove;
establishing a space rectangular coordinate system by taking the center of the lens as an origin, one side of the lens as an x-axis and the adjacent side as a y-axis; the rotation angle of each frequency selective surface is theta,
Figure FDA0002222966070000011
wherein l is the number of orbital angular movements, x and y are the x-axis and y-axis coordinates of the frequency selective surface unit, respectively, the frequency selective surface rotating in a clockwise direction when l is a positive number, and the frequency selective surface rotating in a counterclockwise direction when l is a negative number.
2. The frequency selective surface based cross-polarized vortex beam lens of claim 1, wherein the length L1 of rectangular patch one (2) is 7.5mm, the width W1 is 4mm, the length L2 of rectangular patch two (4) is 7mm, the width W2 is 3mm, and the radius R of the circular groove is 4 mm.
3. The frequency selective surface based cross-polarized vortex beam lens of claim 1 wherein the frequency selective surface elements are square with a side length D of 10 mm.
4. The frequency selective surface based cross-polarized vortex beam lens of claim 1, wherein the dielectric layer (1) has a relative dielectric constant of 3 and a thickness of 1 mm.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111883931A (en) * 2020-08-03 2020-11-03 哈尔滨工业大学 Circularly polarized four-channel independent abnormal deflection lens based on comprehensive phase regulation and control principle of super-structured surface

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105720377A (en) * 2016-01-27 2016-06-29 西安电子科技大学 Novel multi-polarization transmission array antenna
CN105846106A (en) * 2016-05-26 2016-08-10 哈尔滨工业大学 Lens and method for generating Bessel beam carrying orbital angular momentum based on super surface
CN106374232A (en) * 2016-10-26 2017-02-01 中国人民解放军空军工程大学 Ultra-wideband microwave vortex super surface and wideband design method thereof
CN108539417A (en) * 2018-04-26 2018-09-14 西安电子科技大学 A kind of circular polarisation orbital angular momentum reflective array antenna
CN109088170A (en) * 2018-06-05 2018-12-25 中国人民解放军空军工程大学 Super surface spin, wavefront controller and its design method based on principle of interference
CN109301490A (en) * 2018-09-05 2019-02-01 东南大学 A kind of super surface of geometric phase generated applied to broadband multimode vortex wave beam
WO2019108290A9 (en) * 2017-09-15 2019-07-04 President And Fellows Of Harvard College Spin-to-orbital angular momentum converter for light
CN110120588A (en) * 2018-02-06 2019-08-13 深圳市景程信息科技有限公司 The super surface of graphene for being produced from vorticity wave

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105720377A (en) * 2016-01-27 2016-06-29 西安电子科技大学 Novel multi-polarization transmission array antenna
CN105846106A (en) * 2016-05-26 2016-08-10 哈尔滨工业大学 Lens and method for generating Bessel beam carrying orbital angular momentum based on super surface
CN106374232A (en) * 2016-10-26 2017-02-01 中国人民解放军空军工程大学 Ultra-wideband microwave vortex super surface and wideband design method thereof
WO2019108290A9 (en) * 2017-09-15 2019-07-04 President And Fellows Of Harvard College Spin-to-orbital angular momentum converter for light
CN110120588A (en) * 2018-02-06 2019-08-13 深圳市景程信息科技有限公司 The super surface of graphene for being produced from vorticity wave
CN108539417A (en) * 2018-04-26 2018-09-14 西安电子科技大学 A kind of circular polarisation orbital angular momentum reflective array antenna
CN109088170A (en) * 2018-06-05 2018-12-25 中国人民解放军空军工程大学 Super surface spin, wavefront controller and its design method based on principle of interference
CN109301490A (en) * 2018-09-05 2019-02-01 东南大学 A kind of super surface of geometric phase generated applied to broadband multimode vortex wave beam

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
YUXIANG WANG: "《Planar Vortex Beam Generator for Circularly Polarized Incidence Based on FSS》", 《IEEE》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111883931A (en) * 2020-08-03 2020-11-03 哈尔滨工业大学 Circularly polarized four-channel independent abnormal deflection lens based on comprehensive phase regulation and control principle of super-structured surface
CN111883931B (en) * 2020-08-03 2022-06-17 哈尔滨工业大学 Circularly polarized four-channel independent abnormal deflection lens based on comprehensive phase regulation and control principle of super-structured surface

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