阅读说明：本技术 一种基于超表面的5g mimo多波束天线 (5G MIMO multi-beam antenna based on super surface ) 是由 张文梅 罗杰 苏晋荣 陈新伟 马润波 杨荣草 于 2020-03-23 设计创作，主要内容包括：本发明公开了一种基于超表面的5G MIMO多波束天线,由上至下依次包括辐射超表面和馈电网络,超表面和馈电网络中间是高度为h的空气层。其中辐射超表面由上层超表面、一号介质基板和下层超表面组成；馈电网络包括辐射贴片层、二号介质基板、接地板、三号介质基板、馈电微带层；馈电网络部分的辐射贴片层印刷在二号介质基板的上表面,其下表面印刷带缝隙的接地板,三号介质基板上表面与二号介质基板紧密贴合,下表面印刷四条呈旋转对称的微带线。整个超表面天线的结构是呈中心对称的,激励四个馈电端口辐射的四个笔形波束也是旋转对称的。本发明适用于现代无线通信领域,尤其在选择性波束覆盖的应用中有很大的应用前景。(The invention discloses a 5G MIMO multi-beam antenna based on a super surface, which sequentially comprises a radiation super surface and a feed network from top to bottom, wherein an air layer with the height of h is arranged between the super surface and the feed network. The radiation super surface consists of an upper super surface, a first dielectric substrate and a lower super surface; the feed network comprises a radiation patch layer, a second dielectric substrate, a ground plate, a third dielectric substrate and a feed micro-strip layer; the radiation patch layer of the feed network part is printed on the upper surface of the second dielectric substrate, the lower surface of the radiation patch layer is printed with a ground plate with a gap, the upper surface of the third dielectric substrate is tightly attached to the second dielectric substrate, and four microstrip lines which are rotationally symmetrical are printed on the lower surface of the third dielectric substrate. The structure of the whole super-surface antenna is centrosymmetric, and four pencil-shaped beams exciting four feed ports to radiate are also rotationally symmetric. The invention is suitable for the field of modern wireless communication, and particularly has great application prospect in the application of selective beam coverage.)

1. The 5G MIMO multi-beam antenna based on the super-surface is characterized by comprising a radiation super-surface and a feed network which are sequentially arranged from top to bottom, wherein an air layer with the thickness of h is formed between the radiation super-surface and the feed network, the radiation super-surface sequentially comprises an upper super-surface, a first dielectric substrate and a lower super-surface from top to bottom, the upper super-surface and the lower super-surface have the same structure and are respectively attached to the upper surface and the lower surface of the first dielectric substrate, four groups of radiation units arranged in a 2 × 2 array mode are arranged on the upper super-surface and the lower super-surface, the four groups of radiation units are sequentially rotated by 90 degrees around an axis, each group of radiation units comprises seven groups of square patches arranged in a U shape, and the corresponding square patches on the two arms of the U-shaped super-surface of the upper layer and the two arms of the lower super-surface are connected through a short-circuit probe embedded in the center.

2. The super-surface based 5G MIMO multi-beam antenna according to claim 1, wherein: the feed network is concentrically and sequentially provided with a radiation patch layer, a second dielectric substrate, a square grounding plate, a third dielectric substrate and a feed micro-strip layer from top to bottom, and four feed ports are arranged between the square grounding plate and the feed micro-strip layer.

3. The super-surface based 5G MIMO multi-beam antenna according to claim 2, wherein the radiation patch layer is printed on the upper surface of the second dielectric substrate and comprises four diamond-shaped patches arranged in a 2 × 2 array manner.

4. A super-surface based 5G MIMO multi-beam antenna according to claim 3, characterized in that: the back of the second dielectric substrate is printed with a square grounding plate with gaps, and four rectangular gaps are etched on the square grounding plate.

5. The super-surface based 5G MIMO multi-beam antenna according to claim 4, wherein: the four rectangular gaps are sequentially arranged around the axis in a 90-degree rotating mode.

6. The super-surface based 5G MIMO multi-beam antenna according to claim 5, wherein: the feeding micro-strip layer comprises four micro-strip lines which are sequentially arranged around the axis by rotating 90 degrees, one end of each micro-strip line is positioned at the edge of the third dielectric substrate, the other end of each micro-strip line is positioned below the rectangular gap in an extending mode, and the feeding micro-strip layer feeds power to the upper super-surface and the lower super-surface through the rectangular gap and the rhombic patches.

Technical Field

The invention relates to the field of 5G wireless communication, in particular to a 5G MIMO multi-beam antenna based on a super surface.

Background

Multi-beam antennas have seen much room for development in the field of wireless communications, especially in applications requiring selective beam coverage. Such antennas have many advantages such as reducing multipath fading, minimizing radio frequency interference, and realizing beam orientation, and therefore, multi-beam antennas are widely used in the fields of surveillance systems, wireless and satellite communications, smart antennas, doppler radio navigation, and radio altimeters, etc., in communication systems nowadays.

Early multi-beam antennas were implemented with array elements or Butler matrices, (Ge tie, et al, "ANovel Compact Butler Matrix Without Phase Shifter," IEEE microwave and wireless components letters, vol.24, No.5,2014), however, such multi-beam antennas were complex in structure and bulky. After the metamaterial appears, because the metamaterial has unique electromagnetic characteristics such as negative refraction and zero refraction and can control the Propagation of electromagnetic waves by randomly adjusting dielectric constant and magnetic permeability, the metamaterial opens up a new path for realizing a multi-Beam Antenna (Abdolmehdi dadggar, et al. "" Beam-Deflection Using gradient-Index Media for 60-GHz End-Fire Antenna ". IEEE Transactions on antennas and Propagation," 63(8), 3768-materials 3774,2015), however, devices formed by the metamaterial are high in cost, serious in material loss, large in volume, high in profile and limited in Beam control.

Disclosure of Invention

In order to solve the problems of large size and complex structure of the existing multi-beam antenna, the 5G MIMO multi-beam antenna based on the super surface is provided, and the improved miniaturized low-profile multi-beam antenna with the high-impedance super surface is adopted.

The invention provides a 5G MIMO multi-beam antenna based on a super surface, which comprises a radiation super surface and a feed network which are sequentially arranged from top to bottom, wherein an air layer with the thickness of h is formed between the radiation super surface and the feed network, the radiation super surface sequentially comprises an upper super surface, a first dielectric substrate and a lower super surface from top to bottom, the upper super surface and the lower super surface have the same structure and are respectively attached to the upper surface and the lower surface of the first dielectric substrate, the upper super surface and the lower super surface are respectively provided with four groups of radiation units arranged in a 2 × 2 array mode, the four groups of radiation units are sequentially arranged by rotating 90 degrees around an axis, each group of radiation units comprises seven groups of square patches arranged in a U shape, and the corresponding square patches on the U-shaped two arms of the upper super surface and the lower super surface are connected through a short-circuit probe embedded in the center.

As a further improvement of the above scheme, the feed network is concentrically and sequentially provided with a radiation patch layer, a second dielectric substrate, a square ground plate, a third dielectric substrate and a feed micro-strip layer from top to bottom, and four feed ports are arranged between the square ground plate and the feed micro-strip layer.

As a further improvement of the above scheme, the feed network is concentrically and sequentially provided with a radiation patch layer, a second dielectric substrate, a square ground plate, a third dielectric substrate and a feed micro-strip layer from top to bottom.

As a further improvement of the scheme, a square grounding plate with gaps is printed on the back of the second dielectric substrate, and four rectangular gaps are etched on the square grounding plate.

As a further improvement of the scheme, the four rectangular gaps are sequentially arranged around the axis in a 90-degree rotating mode.

As a further improvement of the above scheme, the feeding microstrip layer includes four microstrip lines sequentially arranged by rotating 90 degrees around the axis, one end of each microstrip line is located at the edge of the third dielectric substrate, the other end of each microstrip line is located below the rectangular slot, and the feeding microstrip line feeds the upper super-surface and the lower super-surface through the rectangular slot and the diamond patch.

The invention has the beneficial effects that:

compared with the prior art, after the antenna enters the working state, when the feed port is excited, the electromagnetic wave is transmitted through the microstrip line, is coupled to the rhombic radiation patch through the gap, and then is radiated by the patchThe radiation part of the electromagnetic wave is transmitted out through the gap between the square patches, the other part of the electromagnetic wave is reflected for multiple times in the air layer between the square grounding plate and the radiation super surface, and because the distance between the square grounding plate and the square patches is about lambda/4 and the phase difference between the square grounding plate and the square patches is about pi/2, the electromagnetic wave reflected by the grounding plate and the electromagnetic wave radiated by the square patches can be superposed in phase, so that the gain of the antenna is obviously improved after the super surface is loaded, and the efficiency of the antenna is also improved. Compared with other multi-beam antennas, the invention realizes beam forming by utilizing the simple feed micro-strip layer and the super-surface consisting of the square patches, narrows the beam width, improves the gain of the antenna, avoids using a complex feed network or a complex array element, greatly reduces the volume of the multi-beam antenna, realizes the resonant frequency of the antenna at 7.5GHz, and points to the maximum radiation beam The gain reaches 10.80 dBi.

Drawings

The following detailed description of embodiments of the invention is provided in conjunction with the appended drawings, in which:

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a graph of the reflection coefficient S of the present invention for energizing only port one when loading different components₁₁A schematic diagram;

fig. 3 is a schematic diagram of the super-surface based multi-beam slot antenna and super-surface antenna of the present invention (E-plane radiation direction at 7.5 GHz;

figure 4 is a schematic view of the H-plane radiation direction at 7.5GHz for a super-surface based multi-beam slot antenna of the present invention;

FIG. 5 is a schematic view of the E-plane radiation direction when the beam is rotated by different angles;

FIG. 6 is a schematic view of the radiation direction of the H-plane when the beam is rotated by different angles;

FIG. 7 is a schematic representation of S parameters of a super-surface antenna obtained using HFSS simulation;

fig. 8 is a schematic view of the E-plane (8 ° cross section in azimuth angle Φ) radiation directions obtained when the present invention excites the feed ports one and three, respectively, after loading the super-surface at 7.5 GHz;

fig. 9 is a schematic view of the E-plane (98 ° cross section in azimuth angle Φ) radiation directions obtained when the present invention excites the feed ports two and four, respectively, after loading the super-surface at 7.5 GHz;

fig. 10 is a schematic view of the radiation direction of an H-plane (a section with a pitch angle θ equal to 36 °) obtained by exciting four feed ports respectively after loading a super-surface in the present invention at 7.5 GHz;

fig. 11 is a schematic diagram of the gain of the four-beam antenna of the present invention as a function of frequency.

Detailed Description

As shown in fig. 1, the multi-beam antenna based on the super-surface comprises two parts of a radiation super-surface 1 and a feed network 2 which are sequentially arranged from top to bottom, wherein an air layer with the thickness of h is formed between the radiation super-surface 1 and the feed network 2, the radiation super-surface 1 sequentially comprises an upper super-surface 3, a first dielectric substrate 4 and a lower super-surface 5 from top to bottom, the upper super-surface 3 and the lower super-surface 5 have the same structure, and are respectively attached to the upper surface and the lower surface of the first dielectric substrate 4, the upper super-surface 3 and the lower super-surface 5 are respectively provided with four groups of radiation units 6 arranged in a 2 × 2 array mode, the four groups of radiation units 6 are sequentially arranged by rotating for 90 degrees around an axis, each group of radiation units 6 comprises seven groups of square patches 7 arranged in a U shape, and the square patches 7 corresponding to the two arms of the U-shaped super-surface 3 and the lower super-surface 5 are connected through a short-circuit probe 8 embedded in the center;

the feed network 2 is concentrically and sequentially provided with a radiation patch layer 9, a second dielectric substrate 10, a square ground plate 11, a third dielectric substrate 12 and a feed micro-strip layer 13 from top to bottom, four feed ports 16 are arranged between the square ground plate 11 and the feed micro-strip layer 13, the radiation patch layer 9 is printed on the upper surface of the second dielectric substrate 10 and comprises four diamond patches arranged in a 2 × 2 array mode, the back of the second dielectric substrate 10 is printed with the square ground plate 11 with gaps, four rectangular gaps 15 are etched on the square ground plate 11, the four rectangular gaps 15 are sequentially arranged by rotating 90 degrees around an axis, the feed micro-strip layer 13 comprises four microstrip lines sequentially arranged by rotating 90 degrees around the axis, one end of each microstrip line is located at the edge of the third dielectric substrate 12, the other end of each microstrip line is located below the rectangular gap 15, and feeds the upper super-surface 3 and the lower super-surface 5 through the rectangular gaps 15 and the diamond patches.

FIG. 2 is a reflection coefficient S of the present invention for energizing only port one when loading different components₁₁Schematic representation. Curve 1 is the reflection coefficient S after loading the radiation super-surface 1₁₁Curve 2 shows the reflection coefficient S after loading the dielectric substrate 10 with the diamond-shaped radiating patches 14₁₁Curve 3 shows the reflection coefficient S for operation with only microstrip slot feed unit₁₁As can be seen from fig. 2: by loading the second dielectric substrate 10 printed with the rhombic radiating patches 14, the resonant frequency is reduced from 14.5GHz to 7.5GHz, and then loading the super surface consisting of the square patches 7 and the short-circuit probes 8, although the resonant frequency of the antenna is still 7.5GHz, the depth of the super surface reaches-31.96 dB.

Fig. 3 and 4 are E-plane and H-plane radiation patterns at 7.5GHz for a super-surface based multi-beam slot antenna and a super-surface antenna, respectively. In both figures, curve 1 is a schematic diagram of the radiation directions of an E surface and an H surface when only a basic antenna works under the condition that the radiation super-surface 1 is not loaded; curve 2 is the E-plane and H-plane radiation patterns of the antenna after loading the super-surface, and since the whole antenna is in a centrosymmetric structure, simulation analysis is performed by taking port one as an example, and the results of other ports are similar to port one and are not shown in the figure. In operation, the first excitation port is set to have a center frequency of 7.5GHz, as can be seen from fig. 3 and 4: when the super-surface is not loaded, the radiation pattern is nearly hemispherical, the maximum radiation direction of the beam faces to the positive z-axis, and the beam width is wider. After the super-surface is loaded, the beam width is obviously narrowed, the beams are more concentrated, and the directivity is stronger.

Fig. 5 and 6 mainly discuss factors influencing the antenna performance, and take port one as the port oneFor example, the effects of changing the geometry of the super-surface antenna on the beam width and radiation direction of the antenna were simulated respectively. FIG. 5 is a view in the horizontal direction (in azimuth)) The beam variation is shown schematically, and fig. 6 is a diagram of the beam variation in the vertical direction (along the pitch angle θ). In the figure, the curve 1, the curve 2 and the curve 3 are respectively the maximum radiation directions of the beams (azimuth angles)The radiation pattern when the pitch angle θ) — 0 °,35 °, 8 °,36 °, 19 °,41 ° is known from fig. 5 and 6: the dynamic change range of the maximum direction of the radiation beam in the horizontal direction is 0-19 degrees, and the dynamic change range of the beam in the vertical direction is about 6 degrees; as the beam rotation angle increases, the beam width in the horizontal direction also becomes larger, and the beam width variation in the vertical direction is small.

FIG. 7 is a schematic diagram of S-parameters obtained by HFSS simulation in the present invention. Curve 1 in the figure represents the reflection coefficient of the antenna when four feed ports 16 are excited separately. The curves of the reflection coefficients of the four ports with frequency substantially coincide, so that only S is shown in this figure₁₁. Fig. 7 also shows a schematic diagram of the isolation of the antenna, in which the curves 2, 3, 4 respectively show the isolation S from the antenna port one to the ports two, three, four when the excitation port is one₁₂、S₁₃、S₁₄. As can be seen from fig. 7: the resonant frequency of the antenna is 7.5GHz, and the reflection coefficients S of the four ports₁₁、S₂₂、S₃₃、S₄₄Is about-30 dB. In the frequency band range of 4.5-10.5GHz, S is symmetrical due to the antenna structure₁₂And S₁₄Substantially coincident and separated by a degree of separation S₁₂、S₁₃、S₁₄Are less than-18 dB, (the isolation results for the other ports are similar to port 1 and are not shown in this figure).

Fig. 8 and 9 are schematic diagrams of the E-plane radiation directions obtained by exciting four feed ports 16 respectively after loading the super-surface according to the present invention. Fig. 8 is a radiation pattern obtained in a cross section where an azimuth angle Φ is 8 ° when the first antenna port and the third antenna port are excited, respectively, where a curve 1 represents a beam radiated when only the first antenna port is excited, and a curve 2 represents a beam radiated when only the third antenna port is excited, and included angles between the two beams and the z-axis are both 36 °; fig. 9 shows simulated radiation patterns in a section where the azimuth angle Φ is 98 ° when the antenna port two and the antenna port four are excited, where curve 1 shows a beam radiated by the excitation port two, curve 2 shows a beam radiated by the excitation port four, and two radiation beams are tilted to both sides of the z-axis. Because the whole structure of the antenna is centrosymmetric, the shapes and gains of the four beams are basically the same, but the directions are different.

Fig. 10 is a schematic diagram of the radiation direction of the H-plane (θ ═ 36 ° cross section) obtained by exciting four feed ports 16 after loading the super-surface according to the present invention. Curve 1 represents the beams radiated by excitation ports one and two, and curve 2 represents the beams radiated by excitation ports three and four, as can be seen from a combination of fig. 8 and 9: the maximum radiation directions of the four wave beams of the antenna are respectively (azimuth angle)The pitch angle θ) is (8 °,36 °), (98 °,36 °), (188 °,36 °), (278 °,36 °), the beam pointing effect is good, the side lobe is low, the beam width is narrow, the beam width in the vertical direction is smaller than that in the horizontal direction, and the gain of the beams excited by the four ports is about 10.80 dBi.

FIG. 11 is a graph showing the gain of a four-beam antenna of the present invention as a function of frequency, here illustrated as Port one, in azimuthWhen the pitch angle θ is 36 °, the HFSS software simulates the frequency from 4.5GHz to 10.5GHz, and the gain of the antenna varies with the frequency, as can be seen from fig. 11: the gain of the antenna reaches a maximum at 7.5GHz, which reaches a value of 10.80dBi, and in other frequency ranges the gain of the antenna drops faster.

The above embodiments are not limited to the technical solutions of the embodiments themselves, and the embodiments may be combined with each other into a new embodiment. The above embodiments are only for illustrating the technical solutions of the present invention and are not limited thereto, and any modification or equivalent replacement without departing from the spirit and scope of the present invention should be covered within the technical solutions of the present invention.