A low profile beam steering millimeter wave antenna loaded with huygens super surface

Abstract

The application discloses a low-profile wave beam regulation millimeter wave antenna loaded with Huygens super surface, which comprises a non-biased substrate integrated waveguide slot array antenna and a near-field Huygens super surface; the non-biased substrate integrated waveguide slot array antenna is composed of a first dielectric substrate, metal structures printed on the top and bottom of the first dielectric substrate, a slot array etched on the metal structures and metal through holes in the first dielectric substrate; the near-field Huygens super surface comprises a second dielectric substrate and metal structures on the top and bottom of the second dielectric substrate; the non-biased substrate integrated waveguide slot array antenna serves as an excitation source to provide a spherical wave, and the near-field Huygens super surface is used for precisely regulating the phase distribution above the slot array antenna. The application has the characteristics of low profile and can realize two-dimensional wave beam regulation based on different super surface distributions.

Description

TECHNICAL FIELD

[0001] The application relates to the field of application of a super surface antenna, in particular to a low-profile beam control millimeter wave antenna loaded with a Huygens super surface. BACKGROUND

[0002] The super surface antenna is a new microwave and optical antenna technology, and the wave front regulation of the antenna by using the super surface is a very effective means. The super surface is composed of a large number of sub-wavelength structure units, and can adjust the phase, amplitude and polarization characteristics of the wave. Compared with the traditional antenna, the super surface antenna is smaller in size, lighter in weight, and has significant advantages in radiation directivity, gain and multifunction. This technology has broad application prospects in the fields of 5G communication, radar system and nondestructive imaging.

[0003] A common application of the super surface is to regulate the beam in the radiation pattern, in this case, a horn antenna will be used as an excitation source, and the super surface is placed far above the horn antenna so that the incident wave can be approximated as a plane wave, but this characteristic leads to an increase in the antenna profile height; in recent years, many reports have explored the use of near-field super surfaces to regulate the beam, in which the super surface is located in the near-field region of the antenna, but due to the arrangement of the super surface, it is impossible to realize the regulation of the two-dimensional beam direction. SUMMARY

[0004] The application aims to provide a low-profile beam control millimeter wave antenna loaded with a Huygens super surface, which is used to solve the problems of high profile height of the super surface antenna and the inability to realize two-dimensional beam regulation by using a near-field Huygens super surface, and the Huygens response of the near-field super surface unit and the open-stop-band suppression of the non-biased substrate integrated waveguide slot array antenna are described in principle.

[0005] In order to solve the above technical problems, the technical scheme adopted by the application is as follows: a low-profile beam control millimeter wave antenna loaded with a Huygens super surface, comprising a non-biased substrate integrated waveguide slot array antenna and a near-field Huygens super surface; the non-biased substrate integrated waveguide slot array antenna is composed of a first dielectric substrate, metal structures printed on the top and bottom of the first dielectric substrate, a slot array etched on the metal structure, and metal vias in the first dielectric substrate; the near-field Huygens super surface comprises a second dielectric substrate and metal structures on the top and bottom of the second dielectric substrate.

[0006] Further, the first dielectric substrate is Arlon AD250A, and the thickness is 0.762 mm.

[0007] Further, the metal structure material on the top and bottom of the first dielectric substrate is copper, and the thickness is 0.035 mm.

[0008] Further, the rectangular slot array is arranged at the center of the top metal structure of the first dielectric substrate with a spacing period of 5mm, and the rectangular slots together form an 8*8 rectangular slot array, and the size of a single slot is 3.57mm*0.90mm, and a plurality of metal vias are arranged around the slot.

[0009] Further, the metal vias have a diameter of 0.4mm and a height of 0.762mm, the y direction is along the long direction of the rectangular slot, and a plurality of metal vias at a distance from the slot array in the negative y direction together form a 1 / 8 power divider, and the other part is distributed around the slot array.

[0010] Further, the material of the second dielectric substrate in the Huygens super surface is Arlon AD250A, and the thickness is 1.524mm.

[0011] Further, the metal structure of the near-field Huygens top and bottom is composed of a pair of biased dipoles, Figure 3 The structure of the Huygens super surface unit is shown, and the material of the dipole is copper, and the thickness is 0.035mm.

[0012] Further, the near-field Huygens super surface is placed above the non-biased substrate integrated waveguide slot array antenna at a distance of 0.762mm.

[0013] Compared with the prior art, the beneficial effects of the present application are:

[0014] (1) In view of the problem of high profile of the previous millimeter wave super surface antenna, a new low-profile super surface antenna composed of a non-biased substrate integrated waveguide slot array antenna and a near-field Huygens super surface unit is proposed, and the profile height is only 3.2mm (0.32λ, wherein λ is the working wavelength).

[0015] (2) In view of the problem that the previous near-field super surface cannot realize two-dimensional beam steering in the millimeter wave frequency band, the present application proposes a super surface antenna which can work in the millimeter wave frequency band, the center frequency is 30GHz, and can realize two-dimensional beam scanning based on different super surface distributions, and can effectively control the beam in the millimeter wave frequency band.

[0016] (3) In view of the problem that the previous super surface antenna which can realize two-dimensional beam steering has too many layers, the present application proposes a double-layer super surface antenna which can realize two-dimensional beam scanning, and does not need extra dielectric layers. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The low-profile beam steering millimeter wave antenna structure diagram using Huygens super surface loading is provided.

[0018] Figure 2A schematic diagram of a non-biased substrate integrated waveguide slot array antenna.

[0019] Figure 3 A structural schematic diagram of a Huygens metasurface unit.

[0020] Figure 4 A schematic diagram of an antenna structure for realizing three different beam directions by a low-profile beam steering millimeter wave antenna loaded with a Huygens metasurface.

[0021] Figure 5 A processing physical diagram of a low-profile beam steering millimeter wave antenna loaded with a Huygens metasurface.

[0022] Figure 6 From left to right, respectively, are a comparison diagram of the radiation patterns of antenna simulation and test when the low-profile beam steering millimeter wave antenna loaded with a Huygens metasurface realizes three different beams.

[0023] Figure 7 A comparison diagram of antenna gain of simulation and test of a low-profile beam steering millimeter wave antenna loaded with a Huygens metasurface. DETAILED DESCRIPTION

[0024] In recent years, using a metasurface to perform wavefront regulation of an antenna is a very effective means. In the context of millimeter wave applications, a metasurface is often used to regulate a beam in a radiation pattern, but in this case, a horn is usually used as an excitation source, which has the disadvantage of being too high in overall profile. At the same time, many studies use near-field Huygens metasurfaces to regulate a beam, but most of them cannot be applied to the millimeter wave frequency band. A millimeter wave metasurface antenna that can simultaneously solve the above two problems has become a difficulty now.

[0025] As shown in Figures 1-3 The present application provides a low-profile beam steering millimeter wave antenna loaded with a Huygens metasurface, which comprises a non-biased substrate integrated waveguide slot array antenna 1 and a near-field Huygens metasurface 2. The non-biased substrate integrated waveguide slot array antenna 1 is used as an excitation source to provide a spherical wave, and the near-field Huygens metasurface 2 can accurately regulate the phase distribution above the slot array antenna.

[0026] Firstly, we design the non-biased SIW slot array antenna 1, which includes a 0.762mm thick Arlon AD250A first dielectric substrate 3, a metal structure 4 printed on the top and bottom of the first dielectric substrate with a thickness of 0.035mm, and a rectangular slot array 5 etched on the surface of the metal structure at the center of the top of the first dielectric substrate, with a path width of the SIW and a distance between adjacent slots of 5mm, and a size of a single slot of 3.57mm x 0.90mm. The long side direction of the rectangular slot is the y direction, and the short side direction of the matrix slot is the x direction. A metal via 6 is inserted at a distance of 1.59mm from the center of the matrix slot array in the x direction to change the current distribution, so that the slot can effectively destroy the surface current and promote radiation. Figure 2 The figure shows a schematic diagram of the non-biased SIW slot array antenna. To further illustrate the principle of the proposed non-biased slot array, we design a two-port non-biased slot array with the input port far away from the radiating slot to reduce the influence of excitation, and use the de-embedding technique to eliminate the unnecessary transmission line effect. In the range of 28-32GHz, the beam continuously scans from back to front, indicating that the out-of-band stopband (OSB) is effectively suppressed. We further analyze the suppression of the out-of-band stopband (OSB) using the effective phase constant and attenuation constant, which can be easily calculated using the S parameters obtained by HFSS, as follows:

[0027]

[0028] where 4p represents the total length of the non-biased slot array, a is the attenuation constant, b is the phase constant, S 11 , S 12 , S 21 , S 22 represent the S parameters, and the combination of the slot groove and the via eliminates the OSB effect of the non-biased slot array. We can effectively remove the OSB effect by optimizing the position of the via in the x axis, so that the beam can scan from back to front.

[0029] Subsequently, we design the Huygens super surface, which is composed of a 1.524mm thick Arlon AD250A second dielectric substrate 7 and a metal structure 8 printed on the surface of the second dielectric substrate, and the metal structure 8 is composed of a pair of biased dipoles made of 0.035mm thick copper. Figure 3 The figure shows a structural schematic diagram of the Huygens super surface unit. To explore the resonance characteristics of the proposed Huygens unit, the relationship between the electric sheet admittance Y es and the impedance Z ms of the magnetic sheet is as follows:

[0030]

[0031] where η is the intrinsic impedance of free space, R is the complex reflection coefficient, and T is the complex transmission coefficient. When the real parts of the admittance of the electric sheet and the impedance of the magnetic sheet are approximately zero, a transmission peak excited by the electromagnetic resonance is generated, satisfying the formula:

[0032] Y es η=Z ms / η

[0033] In order to further study the resonance phenomenon, by observing the current distribution on the surface of the two dipoles, it is found that they alternately produce electric resonance and magnetic resonance, which together contribute to the Whittaker nature of the unit.

[0034] Finally, the near-field Huygens metasurface is placed 0.762mm above the non-biased substrate integrated waveguide slot array antenna for integration, and the design of the low-profile beam steering millimeter wave antenna loaded with Huygens metasurface is completed. According to the theory of phased array, the beam pointing where θ0 represents the beam pointing in the elevation plane,

[0035] represents the beam pointing in the azimuth plane, and the following formula can be used for calculation

[0036]

[0037]

[0038] where (φ x ,φ y ) represents the gradient phase difference in the x direction and the y direction, (d x ,d y ) represents the distance of adjacent units in the x direction and the y direction, and the distance and the gradient phase difference of adjacent metasurface units are calculated according to the desired beam pointing.

[0039] The application will be further described in detail in combination with specific embodiments and with reference to the accompanying drawings.

[0040] Example 1

[0041] Figure 4 is a schematic diagram of an antenna structure for realizing 3 different beam pointings, Figure 5The four antenna physical maps processed by the application are composed of non-biased substrate integrated waveguide slot array antennas and near-field Huygens super surfaces, and the overall profile height is 3.2 mm. Compared with the antenna 2, the antenna 1 does not contain the Huygens super surface covered on the upper layer of the slot array antenna. The Huygens super surface in the antenna 2 is composed of a dielectric substrate and metal structures on the top and bottom of the dielectric substrate, the metal structures are composed of a pair of biased dipoles, the long side direction of the rectangular slot is the y direction, the short side direction of the matrix slot is the x direction, and the short side of the third column and the seventh column of dipoles in the x direction has a smaller central angle than other columns. Figure 6 The comparison chart of the simulation and the measured radiation pattern of the application is shown in the following table: Figure 7 The simulation and test comparison chart of the gain of the three antennas with different beam pointing directions is shown in the following table. It is observed from the chart that the antenna 2 realizes a 30° beam pointing in the H plane at a center frequency of 30 GHz, the cross-polarization is lower than -15 dB, the gain in simulation is 18.2 dBi, the measured gain is 16.5 dBi, the radiation efficiency is 71%, and the -10 dB bandwidth is 2%. Compared with the non-biased substrate integrated waveguide slot array antenna 1, it is found that the combination of the super surface leads to a gain deviation range of 1.7 dBi to 2.6 dBi.

[0042] Embodiment 2

[0043] Figure 4 The antenna structure schematic diagram for realizing three different beam pointing directions of the application is shown in the following table: Figure 5 The four antenna physical maps processed by the application are composed of non-biased substrate integrated waveguide slot array antennas and near-field Huygens super surfaces, and the overall profile height is 3.2 mm. Compared with the antenna 3, the antenna 1 does not contain the Huygens super surface covered on the upper layer of the slot array antenna. The Huygens super surface in the antenna 3 is composed of a dielectric substrate and metal structures on the top and bottom of the dielectric substrate, the metal structures are composed of a pair of biased dipoles, the long side direction of the rectangular slot is the y direction, the short side direction of the matrix slot is the x direction, and the short side of the third column and the seventh column of dipoles in the y direction has a smaller central angle than other columns. Figure 6 The comparison chart of the simulation and the measured radiation pattern of the application is shown in the following table: Figure 7The simulation and test comparison graphs of the antenna gains for three antennas with different beam directions are presented. From these graphs, it can be observed that when antenna 3 operates at a center frequency of 30 GHz, it achieves a beam direction of approximately -29° in the E-plane, with cross-polarization far below -20 dB. The simulated gain is 19.2 dBi, the measured gain is 17.5 dBi, the radiation efficiency is 63%, and the -10 dB bandwidth is 1%. Comparing the three antennas of this invention with the non-biased substrate integrated waveguide slot array antenna 1, it is found that incorporating the metasurface results in a ground gain deviation ranging from 1.7 dBi to 2.6 dBi.

[0044] Example 3

[0045] Figure 4 This is a schematic diagram of the antenna structure that enables three different beam orientations according to the present invention. Figure 5 The images show the physical diagrams of the four antennas fabricated according to this invention. The three antennas with different beam directions are all composed of a non-biased substrate integrated waveguide slot array antenna and a near-field Huygens metasurface, with an overall cross-sectional height of 3.2 mm. Compared to antenna 4, antenna 1 does not contain the Huygens metasurface covering the upper layer of the slot array antenna. The Huygens metasurface in antenna 4 consists of a dielectric substrate and metal structures at the top and bottom of the substrate. The metal structures consist of a pair of biased dipoles, with the y-direction along the long side of the rectangular slot and the x-direction along the short side of the matrix slot. The dipoles in the second and sixth rows along the y-direction and the third and seventh rows along the x-direction have smaller central angles than other dipoles. Figure 6 This is a comparison diagram of the simulated and measured radiation patterns of this invention. Figure 7 Simulation and test comparison graphs of antenna gain for three different beam pointing directions are presented. These graphs show that when antenna 4 operates at a center frequency of 30 GHz, it achieves a 45° beam pointing direction in plane D, with cross-polarization below -12 dB, a radiation efficiency of 63%, and a -10 dB bandwidth of 1%. Comparing the three antennas of this invention with the non-biased substrate integrated waveguide slot array antenna 1, it is found that incorporating the metasurface results in a ground gain deviation ranging from 1.7 dBi to 2.6 dBi.

[0046] The above embodiments are merely illustrative of the structure, principle, and effect of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A low profile beam-steerable millimeter wave antenna loaded with a Huygens super surface, characterized in that, The application relates to a non-biased substrate integrated waveguide slot array antenna (1) and a near-field Huygens super surface (2); the non-biased substrate integrated waveguide slot array antenna (1) is composed of a first dielectric substrate (3), metal structures (4) printed on the top and bottom of the first dielectric substrate, a slot array (5) etched on the top metal structure, and metal through holes (6) in the first dielectric substrate; the near-field Huygens super surface comprises a second dielectric substrate (7) and metal structures (8) on the top and bottom of the second dielectric substrate; the near-field Huygens super surface (2) is placed at a certain distance above the non-biased substrate integrated waveguide slot array antenna (1).

2. The Huygens metasurface loaded low-profile beam steering millimeter wave antenna according to claim 1, wherein, The first dielectric substrate (3) is Arlon AD250A, and the thickness is 0.762 mm.

3. The Huygens metasurface loaded low-profile beam steering millimeter wave antenna according to claim 1, wherein, The metal structures (4) on the top and bottom of the first dielectric substrate are made of copper, and the thickness is 0.035 mm.

4. The Huygens super surface loaded low-profile beam steering millimeter wave antenna according to claim 1, wherein the rectangular slot array (5) is an 8*8 rectangular slot array.

5. The Huygens metasurface loaded low-profile beam steering millimeter wave antenna according to claim 4, wherein, The rectangular slot array (5) is arranged at the center of the top metal structure of the first dielectric substrate with a spacing period of 5 mm, the size of a single slot is 3.57 mm*0.90 mm, and a plurality of metal through holes are arranged around the slot.

6. The Huygens metasurface loaded low-profile beam steering millimeter wave antenna according to claim 5, wherein, The metal through holes (6) have a diameter of 0.4 mm and a height of 0.762 mm.

7. The Huygens metasurface loaded low-profile beam steering millimeter wave antenna according to claim 6, wherein, The metal through holes along the direction of the long side of the rectangular slot are arranged in the y direction, and a plurality of metal through holes arranged at a certain distance from the slot array in the negative y direction together form a 1 / 8 power divider, and the other metal through holes are distributed around the slot array.

8. The Huygens metasurface loaded low-profile beam steering millimeter wave antenna according to claim 1, wherein, The second dielectric substrate (7) in the Huygens super surface is made of Arlon AD250A, and the thickness is 1.524 mm.

9. The Huygens metasurface loaded low-profile beam steering millimeter wave antenna according to claim 1, wherein, The metal structures (8) on the top and bottom of the near-field Huygens super surface are composed of a pair of biased dipoles, the material of the dipoles is copper, and the thickness is 0.035 mm.

10. The Huygens metasurface loaded low-profile beam steering millimeter wave antenna according to claim 1, wherein, The near-field Huygens super surface (2) is placed at a distance of 0.762 mm above the non-biased substrate integrated waveguide slot array antenna (1).

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