5g millimeter wave dual-band antenna based on multilayer metasurface

Abstract

The application discloses a 5G millimeter wave dual-frequency antenna based on a multilayer metasurface and belongs to the field of radio frequency front-end devices; the upper surface of a lower dielectric layer is provided with a slotted patch, and the lower surface of the lower dielectric layer is provided with a metal ground; the slotted patch is a square metal plate, which is provided with a first L-shaped slot and a second L-shaped slot; the two branch ends of the first L-shaped slot are provided with extension sections; the first L-shaped slot and the second L-shaped slot surround a square ring, and the extension section and the branch of the first L-shaped slot adjacent to the extension section have a spacing greater than zero; the upper surface of a middle dielectric layer is provided with a lower metasurface structure; the lower metasurface structure is composed of multiple metasurface units arranged in a rectangular array mode; the upper surface of an upper dielectric layer is provided with an upper metasurface structure; and a feeding structure is located on the upper surface of the lower dielectric layer. The application can produce dual frequency bands by slitting the patch antenna, load double-layer metasurface structures above the patch antenna, and increase the frequency band width and the beam width of the antenna.

Description

Technical Field

[0001] This invention relates to a 5G millimeter-wave dual-band antenna with a multi-layer metasurface structure, which is mainly used in wireless broadband networks and belongs to the field of radio frequency front-end devices. Background Technology

[0002] With the continuous advancement and popularization of 5G technology, millimeter wave technology has become an important component of 5G mobile communication. Millimeter wave (mmWave) refers to electromagnetic waves with frequencies between 30GHz and 300GHz, and its wavelength range is approximately 1mm to 10mm. Compared to the low-frequency bands used by previous mobile communication technologies (such as 4G LTE), the millimeter wave band has higher bandwidth and faster transmission speed.

[0003] However, due to the unique characteristics of the millimeter-wave band, such as short transmission distance, weak penetration, and susceptibility to obstruction, communication in this band requires more complex antenna designs to overcome these challenges. Therefore, designing an efficient and reliable millimeter-wave antenna has become one of the key aspects of realizing 5G technology.

[0004] In the background technology of 5G millimeter-wave dual-band antennas, the following aspects mainly need to be considered:

[0005] 1. Antenna frequency range: 5G millimeter wave communication covers two frequency bands, 28GHz and 38GHz, so an antenna that can support both frequency bands at the same time needs to be designed.

[0006] 2. Antenna Directivity: Since the signal transmission distance in the millimeter wave band is relatively short, it is necessary to design an antenna with strong directivity to enhance the signal transmission strength and distance.

[0007] 3. Antenna size and weight: Millimeter wave bands have shorter wavelengths, so the antenna size is correspondingly smaller. However, it is necessary to ensure that the antenna is lightweight so that it can be used in mobile devices.

[0008] 4. Antenna cost: Since millimeter-wave antennas require more complex designs, their costs are correspondingly higher. It is necessary to find a design solution that can meet performance requirements while reducing costs.

[0009] Based on the above considerations, the design of 5G millimeter-wave dual-band antennas needs to combine antenna theory and practical application requirements to find a design scheme that can meet the requirements of high-speed, high-bandwidth communication, and achieve high efficiency, reliability, lightness, and low cost. Summary of the Invention

[0010] To address the problems existing in the background technology, this invention designs a 5G millimeter-wave dual-band antenna based on a multi-layer metasurface, which can meet the requirements of covering both 28G and 38G frequency bands. The designed antenna achieves the characteristics of simple structure, convenient design, wide beam, and wide bandwidth.

[0011] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0012] The 5G millimeter-wave dual-band antenna based on a multilayer metasurface includes upper, middle, and lower dielectric layers. A metal ground is provided on the lower surface of the lower dielectric layer, and a slotted patch is provided on the upper surface of the lower dielectric layer. The slotted patch is a square metal plate with a first L-shaped slot and a second L-shaped slot. Each of the two ends of the first L-shaped slot has an extension segment, and the extension segment is perpendicular to the connected segment. The first and second L-shaped slots form a square ring, and there is a greater than zero gap between the extension segment and the adjacent second L-shaped slot segment.

[0013] The upper surface of the intermediate dielectric layer is provided with a lower metasurface structure; the lower metasurface structure is composed of multiple metasurface units arranged in a rectangular array.

[0014] The upper surface of the upper dielectric layer is provided with an upper metasurface structure;

[0015] The power feeding structure is located on the upper surface of the lower dielectric layer; it mainly consists of a microstrip line, a centrally open microstrip line, and symmetrical microstrip lines; the centrally open microstrip line is a square ring structure, with one side being an opening, and the two ends of the opening being connected to the slotted patch through corresponding symmetrical microstrip lines, and both symmetrical microstrip lines are perpendicular to the edge of the slotted patch; one end of the microstrip line is connected to the opposite side of the opening of the centrally open microstrip line, and the two are perpendicular to each other, and the other end of the microstrip line extends outward.

[0016] Furthermore, the branch length of the first L-shaped groove is greater than the branch length of the second L-shaped groove.

[0017] Furthermore, the central axis of the upper supersurface structure and the central axis of the lower supersurface structure coincide.

[0018] Furthermore, the upper metasurface structure includes peripheral metasurface units, inner metasurface units, and a central metasurface unit; wherein, multiple inner metasurface units form an inner square ring, and the peripheral metasurface units surround the outer side of the inner square ring; the central metasurface unit is located at the center of the inner square ring.

[0019] Furthermore, the metasurface unit, the central metasurface unit, and the peripheral metasurface unit are completely identical, and the length and width of all three are smaller than the length and width of the inner perimeter metasurface unit.

[0020] Furthermore, the relative permittivity of the upper and lower dielectric layers is 3.55, and the dielectric loss tangent is 0.0027; the relative permittivity of the middle dielectric layer is 3.66, and the dielectric loss tangent is 0.004.

[0021] Compared with the prior art, the present invention can generate dual frequency bands by slotting the patch antenna and loading a double-layer metasurface structure on it, thereby increasing the frequency band bandwidth and the antenna beamwidth. Attached Figure Description

[0022] Figure 1 This is a top view of the antenna slotted patch layer structure;

[0023] Figure 2 This is a top view of the metasurface structure beneath the antenna.

[0024] Figure 3 This is a top view of the metasurface structure on the upper layer of the antenna;

[0025] Figure 4 This is a side view of the antenna structure;

[0026] Figure 5 This is a reflection coefficient curve of a 5G millimeter-wave dual-band antenna based on metasurfaces;

[0027] Figure 6 Far-field radiation pattern of a 5G millimeter-wave dual-band antenna based on metasurface; Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1-6 The embodiments and examples will further illustrate specific implementations of the present invention in detail.

[0029] The 5G millimeter-wave dual-band antenna based on a multilayer metasurface includes upper, middle, and lower dielectric layers. The lower surface of the lower dielectric layer has a metal ground, and the upper surface has a slotted patch. The slotted patch is a square metal plate with a first L-shaped slot and a second L-shaped slot. The two ends of the first L-shaped slot have extensions, and the extensions are perpendicular to the connected segments. The first and second L-shaped slots form a square ring, and there is a greater than zero gap between the extensions and the adjacent segments of the first L-shaped slot.

[0030] The upper surface of the intermediate dielectric layer is provided with a lower metasurface structure; the lower metasurface structure is composed of multiple metasurface units arranged in a rectangular array.

[0031] The upper surface of the upper dielectric layer is provided with an upper metasurface structure;

[0032] The feeding structure is located on the upper surface of the lower dielectric layer; it mainly consists of a microstrip line, a microstrip line with a central opening, and symmetrical microstrip lines; the microstrip line with the central opening has a square ring structure, with one side being an opening, and the two ends of the opening being connected to a metal patch through corresponding symmetrical microstrip lines, and both symmetrical microstrip lines are perpendicular to the patch; one end of the microstrip line is connected to the opposite side of the opening of the microstrip line with the central opening, and the two are perpendicular to each other, and the other end of the microstrip line extends outward.

[0033] Furthermore, the branch length of the first L-shaped groove is greater than the branch length of the second L-shaped groove.

[0034] Furthermore, the central axis of the upper supersurface structure and the central axis of the lower supersurface structure coincide.

[0035] Furthermore, the upper metasurface structure includes peripheral metasurface units, inner metasurface units, and a central metasurface unit; wherein, multiple inner metasurface units form an inner square ring, and the peripheral metasurface units surround the outer side of the inner square ring; the central metasurface unit is located at the center of the inner square ring.

[0036] Furthermore, the metasurface unit, the central metasurface unit, and the peripheral metasurface unit are completely identical, and the length and width of all three are smaller than the length and width of the inner perimeter metasurface unit.

[0037] The following is a more specific example:

[0038] refer to Figures 1 to 4 , Figure 1 This is a top view of the antenna slotted patch layer structure. Figure 2 This is a top view of the underlying metasurface structure of the antenna. Figure 3 This is a top view of the metasurface structure on the upper layer of the antenna. Figure 4 This is a side view of the antenna structure. (Example) Figures 1 to 4 As shown, the antenna consists of dielectric layers 29, 30, and 31, a metallic ground, upper metasurfaces 23 and 24, a lower metasurface 19, and a slotted metal patch 2. The slotted metal patch 2 is formed by hollowing out a smaller rectangle in the center and two "L" shapes around the edges of a larger square metal piece, located above the bottom dielectric layer, enabling the generation of the required millimeter-wave dual-band frequencies. The microstrip feed and the slotted metal patch are on the same layer, which affects the antenna's impedance matching. Metasurface structure 19, on the second dielectric layer, after being appropriately sized and arrayed, creates two new frequency bands. To move these bands to 28 GHz and 38 GHz, thereby expanding the bandwidth, metasurface structures 23 and 24 are loaded on the top dielectric layer. By changing their size and forming a suitable array, the frequency bands can be shifted to the 5 GHz millimeter-wave band. The height of the dielectric layer affects the antenna's radiation pattern performance.

[0039] Therefore, selecting appropriate metal patch size 2, L-shaped slot lengths 5, 6, 7, 8, 9 and width 10, metasurface element sizes 19, 23, 24, and dielectric layer heights 29, 30, 31 will have a significant impact on the antenna's bandwidth and far-field radiation pattern, specifically manifested as follows:

[0040] a) When the size of the metal patch 2 is changed, the center frequency of both bands will change, but the change in the lower band is more obvious than the change in the upper band.

[0041] b) The width 10 of the "L" shape of the metal patch will affect the movement of the dual bands. As the gap widens, the upper band moves upward and the lower band moves downward. The lengths of gaps 6 and 7 will affect the impedance matching of the upper and lower bands of the antenna, respectively. The lengths of gaps 8 and 9 will also affect the movement of the frequency band, but the impact is not significant.

[0042] c) After the metasurface unit 19 is arranged into a 6*6 array, it can generate additional dual-band frequencies, but not on the 28G and 38G bands.

[0043] d) Metasurface units 23 and 24 can move the new frequency band generated by metasurface unit 19 to a lower frequency. When a suitable array is formed, the generated new frequency band can be moved to the 28G and 38G frequency bands, thereby expanding the bandwidth.

[0044] e) The thickness of dielectric layers 29, 30, and 31 affects the antenna's beamwidth, while microstrip feed 12 and slot 16 improve the antenna's impedance matching. The positions of microstrip feeds 17 and 18 and the width of microstrip line 14 affect the antenna's impedance matching. As the positions of microstrip lines 17 and 18 increase, the low-frequency band shifts to higher frequencies, and as the width of microstrip line 14 increases, the high-frequency band shifts to lower frequencies.

[0045] Therefore, selecting appropriate metal patch size 2, L-shaped slot lengths 5, 6, 7, 8, 9 and width 10, and metasurface element sizes 19, 23, 24 are of great significance for improving the performance of the inner arc microstrip antenna.

[0046] This 5G millimeter-wave dual-band antenna based on a multi-layer metasurface is illustrated here using one of the following size combinations (the data below are in millimeters):

[0047] when Figure 1 The dimensions of the structure are:

[0048] Structure 1 = 6.8, Structure 2 = 3.1, Structure 3 = 0.98, Structure 4 = 0.9, Structure 5 = 2.7, Structure 6 = 0.5, Structure 7 = 0.5, Structure 8 = 1.85, Structure 9 = 1.65, Structure 10 = 0.2, Structure 11 = 0.9, Structure 12 = 0.2, Structure 13 = 0.15, Structure 14 = 0.2, Structure 15 = 0.15, Structure 16 = 0.5, Structure 17 = 400, Structure 18 = 1.85;

[0049] when Figure 2 The dimensions of the structure are:

[0050] Structure 19 = 0.4, Structure 20 = 0.23, Structure 21 = 1.9, Structure 22 = 1.9.

[0051] when Figure 3 The dimensions of the structure are:

[0052] Structure 23 = 0.45, Structure 24 = 0.63, Structure 25 = 0.18, Structure 26 = 0.02, Structure 27 = 1.9, Structure 28 = 1.93;

[0053] The total thickness of substrate 29 is 0.254, the total thickness of substrate 30 is 0.1, the total thickness of substrate 31 is 0.9, and the thickness of the metal layer of the microstrip line and the metal ground is 0.018.

[0054] At this time, the simulation diagram of the antenna reflection coefficient is as follows: Figure 5 As shown.

[0055] Figure 5 The reflection coefficient curve of the 5G millimeter-wave dual-band antenna is shown. The S11 of the antenna is significantly less than -10dB in the frequency range of 23.9-28.2GHz and significantly less than -10dB in the frequency range of 37.2-40.7GHz.

[0056] At this time, the antenna far-field radiation pattern is as follows: Figure 6 As shown.

[0057] Figure 6 The image shows the far-field lobe pattern of the 5G millimeter-wave dual-band antenna at its center frequency of 28 GHz, with a half-power beamwidth of ±60°.

[0058] It is evident that a 5G millimeter-wave dual-band antenna based on a multi-layer metasurface can simultaneously cover both the 28GHz and 38GHz frequency bands, achieving a relative impedance bandwidth of 15% for the low-frequency band and 10% for the high-frequency band, with a half-power beamwidth of ±60°.

[0059] The above is just one example. To obtain dual-band antennas with different center frequencies, different parameters can be adjusted according to the specific implementation method. For example, the center frequency of the antenna can be adjusted by changing the slot size of the patch antenna and the thickness of the dielectric substrate, and the impedance matching can be adjusted by adjusting the size and arrangement of the metasurface structure.

Claims

1. A 5G millimeter wave dual-band antenna based on multilayer metasurface, comprising upper, middle and lower three dielectric layers; characterized in that, The lower surface of the lower dielectric layer is provided with a metal ground, and the upper surface of the lower dielectric layer is provided with a slotted patch; the slotted patch is a square metal plate, which is provided with a first L-shaped slot and a second L-shaped slot; wherein the two branch ends of the first L-shaped slot are each provided with an extension, and the extension is perpendicular to the branch connected thereto; the first L-shaped slot and the second L-shaped slot form a square ring, and the extension and the branch of the second L-shaped slot adjacent thereto have a spacing greater than zero; The upper surface of the intermediate dielectric layer is provided with a lower metasurface structure; the lower metasurface structure is composed of a plurality of metasurface units (19) arranged in a rectangular array; The upper surface of the upper dielectric layer is provided with an upper metasurface structure; The feeding structure is located on the upper surface of the lower dielectric layer; it is mainly composed of a microstrip line, an intermediate open microstrip line and symmetrical microstrip lines; the intermediate open microstrip line is a square ring structure, one side of which is an opening, and the two ends of the opening are respectively connected to the slotted patch through corresponding symmetrical microstrip lines, and the two symmetrical microstrip lines are perpendicular to the edge of the slotted patch; one end of the microstrip line is connected to the opposite side of the opening of the intermediate open microstrip line, and the two are perpendicular to each other, and the other end of the microstrip line extends outward; The upper metasurface structure includes peripheral metasurface units, inner metasurface units and a central metasurface unit; wherein a plurality of inner metasurface units form an inner square ring, and the peripheral metasurface units are located outside the inner square ring; the central metasurface unit is located at the center of the inner square ring; The metasurface units, the central metasurface unit and the peripheral metasurface units are completely the same, and the length and width of the three are smaller than the length and width of the inner metasurface units.

2. The multi-layer metasurface based 5G mmWave dual-band antenna of claim 1, wherein, The branch length of the first L-shaped slot is greater than the branch length of the second L-shaped slot.

3. The multi-layer metasurface based 5G mmWave dual-band antenna of claim 1, wherein, The central axis of the upper metasurface structure coincides with the central axis of the lower metasurface structure.

4. The multi-layer metasurface based 5G mmWave dual-band antenna of claim 1, wherein, The relative dielectric constant of the upper and lower dielectric layers is 3.55, and the dielectric loss tangent is 0.0027; the relative dielectric constant of the intermediate dielectric layer is 3.66, and the dielectric loss tangent is 0.004.

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