Electromagnetic decoupling structure for 5.5g communication system based on high rejection three-dimensional metasurface

Abstract

This invention discloses an electromagnetic decoupling structure for a 5.5G communication system based on a high-suppression three-dimensional metasurface. The structure is composed of multiple identical periodic units arranged and spliced ​​together. Each periodic unit includes an upper antenna layer, an intermediate vertical layer, and a lower antenna layer, with the upper and lower antenna layers connected by multiple intermediate vertical layers. Cross-shaped metal strips are etched on the upper surface of the upper layer and the lower surface of the lower layer, and are electrically connected through the intermediate vertical layers. When spatial electromagnetic waves strike the three-dimensional metasurface, a null point is generated due to the coupling between the cross-shaped metal strips and the vertical surface, providing excellent suppression of electromagnetic waves in the stopband and without interfering with the passband generated by the gaps. This invention achieves low passband insertion loss while also exhibiting high stopband suppression, roll-off velocity, and angular stability, making it highly valuable for applications such as multi-frequency antenna decoupling in mobile communications.

Description

Technical Field

[0001] This invention relates to an electromagnetic decoupling structure in the field of electromagnetic fields and microwave technology, specifically an electromagnetic decoupling structure for a 5.5G communication system based on a three-dimensional metasurface with high out-of-band suppression. Background Technology

[0002] With the rapid development of the communication technology industry, the frequency bands used are becoming increasingly diverse, while the increasingly scarce site resources place higher demands on future base station antennas to support multiple frequency bands. Multi-band combined common-plane array antennas suffer from mutual coupling problems, leading to a severe deterioration of radiation pattern performance. Therefore, a solution to this problem is urgently needed.

[0003] Common-aperture technology refers to the close combination of antenna elements of different frequency bands according to a specific structure, sharing part or all of the radiation aperture, and operating normally within their respective frequency bands without interfering with each other. A three-dimensional metasurface can interact with spatial electromagnetic waves to filter them, suppressing the coupling effects between high- and low-frequency elements. Therefore, a metasurface is needed to generate a high-suppression stopband at low frequencies to effectively suppress the influence of low-frequency elements, and a low-insertion-loss passband at high frequencies so that the radiation from high-frequency elements can easily penetrate low-frequency elements. Furthermore, it needs to possess a certain degree of angular stability to reduce the coupling effects between low-frequency elements.

[0004] In practical applications, metasurfaces are often required to have low passband insertion loss, high stopband suppression, fast roll-off speed and good angular stability. However, existing metasurfaces often perform well in several of these aspects, and achieving good performance in all of these aspects remains a significant challenge. Summary of the Invention

[0005] To address the challenge of reducing passband insertion loss and improving stopband suppression, roll-off velocity, and angular stability to meet the decoupling requirements of multi-band antennas, an electromagnetic decoupling structure for 5.5G communication systems based on a three-dimensional metasurface with high out-of-band suppression is proposed. Through a design combining four metal layers with a vertical surface, this structure achieves both low passband insertion loss and high stopband suppression, roll-off velocity, and angular stability, making it suitable for mobile communication applications such as decoupling of multi-band antennas.

[0006] The technical solution adopted in this invention:

[0007] I. An electromagnetic decoupling structure for a 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface

[0008] The electromagnetic decoupling structure of the 5.5G communication system based on a high-suppression three-dimensional metasurface is composed of multiple identical periodic units arranged and spliced ​​together. Each periodic unit includes an upper antenna layer, an intermediate vertical layer, and a lower antenna layer. The upper antenna layer and the lower antenna layer are connected by multiple intermediate vertical layers.

[0009] The upper antenna layer includes an upper cross-shaped metal strip, an upper dielectric substrate, and an upper metal layer. The upper and lower surfaces of the upper dielectric substrate are respectively covered with the upper cross-shaped metal strip and the upper metal layer. An upper gap is opened in the upper metal layer, which divides the upper metal layer into an upper inner metal layer and an upper outer metal layer. Mounting holes are opened around the upper dielectric substrate at the upper outer metal layer. The upper end of each intermediate vertical layer is embedded in the corresponding mounting hole. Each branch end of the upper cross-shaped metal strip is electrically connected to the upper end of the corresponding intermediate vertical layer. The upper outer metal layer is electrically connected to the upper end of each intermediate vertical layer.

[0010] The lower antenna layer includes a lower cross-shaped metal strip, a lower dielectric substrate, and a lower metal layer. The lower cross-shaped metal strip and the lower metal layer are respectively laid on the upper and lower surfaces of the lower dielectric substrate. A lower gap is opened in the lower metal layer, which divides the lower metal layer into an inner lower metal layer and an outer lower metal layer. Mounting holes are opened around the lower dielectric substrate at the outer lower metal layer. The upper end of each intermediate vertical layer is embedded in the corresponding mounting hole. Each branch end of the lower cross-shaped metal strip is electrically connected to the lower end of the corresponding intermediate vertical layer. The outer lower metal layer is electrically connected to the lower end of each intermediate vertical layer.

[0011] The intermediate vertical layer includes a vertical dielectric substrate, an upper vertical metal layer, and a lower vertical metal layer; the upper and lower vertical metal layers are respectively laid on the upper and lower parts of one side of the vertical dielectric substrate, and an intermediate layer gap is provided between the upper and lower vertical metal layers. The upper vertical metal layer is electrically connected to the upper antenna layer, and the lower vertical metal layer is electrically connected to the lower antenna layer.

[0012] In the adjacent periodic units, the upper outer metal layers of the upper metal layer are interconnected; in the adjacent periodic units, the lower outer metal layers of the lower metal layer are interconnected.

[0013] The upper and lower metal layers are symmetrical and both have a square shape.

[0014] The shape of the gap in the intermediate layer can be arbitrary.

[0015] The shape of the gap in the intermediate layer can be a straight line, a broken line, or a curve.

[0016] The upper and lower dielectric substrates are made of F4B material with a dielectric constant of 3 and a dielectric loss tangent of 0.001.

[0017] II. Application of an electromagnetic decoupling structure for a 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface.

[0018] The application of the electromagnetic decoupling structure of the 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface in the decoupling of multi-band antennas.

[0019] The beneficial effects of this invention are:

[0020] Although the metasurface of this invention has a three-dimensional structure, it can still be processed using traditional PCB manufacturing processes.

[0021] The upper and lower slits of this invention provide a passband with low insertion loss for the three-dimensional metasurface. Under normal incidence of spatial electromagnetic waves, the average insertion loss of TE and TM modes in the passband frequency range of 3.3-3.8 GHz is less than 0.23 dB; under oblique incidence of spatial electromagnetic waves at 60 degrees, the average insertion loss of TE mode in the passband frequency range of 3.3-3.8 GHz is less than 0.95 dB, and the average insertion loss of TM mode in the passband frequency range of 3.3-3.8 GHz is less than 0.18 dB.

[0022] The upper and lower cross-shaped metal strips and the vertical metal surface of this invention provide a stopband with a large stopband suppression degree for the three-dimensional metasurface. Under normal incidence of spatial electromagnetic waves, the stopband suppression degree of TE and TM modes is greater than 20dB in the 0-1GHz stopband frequency range and greater than 16.3dB in the 1.4-2.69GHz stopband frequency range. Under oblique incidence of spatial electromagnetic waves at 60 degrees, the stopband suppression degree of TE mode is greater than 20dB in the 0-1GHz stopband frequency range and greater than 24dB in the 1.4-2.69GHz stopband frequency range; the stopband suppression degree of TM mode is greater than 18.5dB in the 0-1GHz stopband frequency range and greater than 15dB in the 1.4-2.69GHz stopband frequency range.

[0023] This invention has significant application value in mobile communication fields such as multi-band antenna decoupling. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structure diagram of the metasurface according to an embodiment of the present invention.

[0025] Figure 2 This is a three-dimensional structural diagram of the periodic unit structure in this invention.

[0026] Figure 3 This is a front view of the periodic unit structure in this invention.

[0027] Figure 4This is a structural view of the vertical metal surface in this invention.

[0028] Figure 5 This is a structural view of the cross-shaped metal strip in this invention.

[0029] Figure 6 This is a structural view of the slit in this invention.

[0030] Figure 7 This is the transport characteristic curve of the three-dimensional metasurface in this invention.

[0031] Figure 8 This is the curve showing the effect of the electromagnetic wave incident angle on the three-dimensional metasurface in this invention under TE mode.

[0032] Figure 9 This is the curve showing the effect of the electromagnetic wave incident angle on the three-dimensional metasurface in this aspect under TM mode.

[0033] In the diagram: 1. Upper cross-shaped metal strip, 2. Upper dielectric plate, 3. Upper gap, 4. Vertical dielectric plate, 5. Vertical metal surface, 6. Lower gap, 7. Lower dielectric plate, 8. Lower cross-shaped metal strip, 5a. Middle layer gap, 5b. Metal patch. Detailed Implementation

[0034] To illustrate the technical solutions disclosed in this invention in detail, further explanation will be provided below with reference to the accompanying drawings and specific embodiments.

[0035] like Figure 1 As shown, the electromagnetic decoupling structure of the 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface of the present invention is composed of multiple identical periodic units arranged and spliced ​​in a matrix array, as follows: Figure 2 As shown, each periodic unit includes an upper antenna layer, an intermediate vertical layer, and a lower antenna layer, with the upper and lower antenna layers connected by multiple intermediate vertical layers.

[0036] like Figure 3As shown, the upper antenna layer includes an upper cross-shaped metal strip 1, an upper dielectric substrate 2, and an upper metal layer. The upper and lower surfaces of the upper dielectric substrate 2 are respectively covered with the upper cross-shaped metal strip 1 and the upper metal layer. Alternatively, the upper cross-shaped metal strip 1 is laid on the upper surface of the upper dielectric substrate 2, and the upper metal layer is laid on the lower surface of the upper dielectric substrate 2; or the upper metal layer is laid on the upper surface of the upper dielectric substrate 2, and the upper cross-shaped metal strip 1 is laid on the lower surface of the upper dielectric substrate 2. An upper gap 3 is formed in the upper metal layer, dividing the upper metal layer into an inner upper metal layer and an outer upper metal layer. The upper gap 3 is also bendable. Mounting holes are formed around the upper dielectric substrate 2 at the outer upper metal layer. The upper end of each intermediate vertical layer is embedded in the corresponding mounting hole. Each branch end of the upper cross-shaped metal strip 1 is electrically connected to the upper end of the corresponding intermediate vertical layer, and the outer upper metal layer is electrically connected to the upper ends of each intermediate vertical layer.

[0037] The lower antenna layer includes a lower cross-shaped metal strip 8, a lower dielectric substrate 7, and a lower metal layer. The lower cross-shaped metal strip 8 and the lower metal layer are respectively laid on the upper and lower surfaces of the lower dielectric substrate 7. The lower cross-shaped metal strip 8 is laid on the upper surface of the lower dielectric substrate 7, and the lower metal layer is laid on the lower surface of the lower dielectric substrate 7, or the lower metal layer is laid on the upper surface of the lower dielectric substrate 7, and the lower cross-shaped metal strip 8 is laid on the lower surface of the lower dielectric substrate 7. A lower gap 6 is formed in the lower metal layer, which divides the lower metal layer into an inner lower metal layer and an outer lower metal layer. The lower gap 6 is tortuous in the same way as the upper gap 3. Mounting holes are formed around the lower dielectric substrate 7 at the outer lower metal layer. The upper end of each intermediate vertical layer is embedded in the corresponding mounting hole. Each branch end of the lower cross-shaped metal strip 8 is electrically connected to the lower end of the corresponding intermediate vertical layer, and the lower outer metal layer is electrically connected to the lower end of each intermediate vertical layer.

[0038] like Figure 4 As shown, the intermediate vertical layer includes a vertical dielectric substrate 4, an upper vertical metal layer, and a lower vertical metal layer. The upper and lower vertical metal layers are respectively laid on the upper and lower parts of one side (inner or outer side) of the vertical dielectric substrate 4. Both the upper and lower vertical metal layers are metal patches 5b. An intermediate layer gap 5a is provided between the upper and lower vertical metal layers, separating them. The upper vertical metal layer is electrically connected to the corresponding branch ends of the upper outer metal layer and the upper cross-shaped metal strip 1 of the upper antenna layer, and the lower vertical metal layer is electrically connected to the corresponding branch ends of the lower outer metal layer and the lower cross-shaped metal strip 8 of the lower antenna layer.

[0039] In adjacent periodic cells, the upper outer metal layers of the upper metal layers are interconnected. In adjacent periodic cells, the lower outer metal layers of the lower metal layers are interconnected.

[0040] The upper and lower metal layers are symmetrical, and both are square in shape.

[0041] The shape of the intermediate layer gap 5a can be arbitrary. Specifically, the shape of the intermediate layer gap 5a can be a straight line, a broken line, or a curve.

[0042] The upper dielectric substrate 2 and the lower dielectric substrate 7 are made of F4B material with a dielectric constant of 3 and a dielectric loss tangent of 0.001.

[0043] like Figure 4 As shown, the vertical dielectric plate of the present invention has a vertical metal surface on one side, with the gap located in the center of the vertical metal surface and parallel to the short side of the vertical metal surface, and metal patches on both sides. The vertical dielectric plate is made of F4B material with a thickness of 0.5mm, a dielectric constant of 3, and a dielectric loss tangent of 0.001. Lx = 3mm, T1 = 1mm, Ht = 0.2mm, Lfw = 1mm, Bk = 1, H = 17mm.

[0044] like Figure 5 As shown, the structural parameters of the cross-shaped metal strip of the present invention are: D = 25.9 mm, Lp = 1.5 mm, Lky = 0.5 mm, Lk = 0.2 mm, Cl = 1.2 mm, Ck = 0.8 mm, Bk = 1 mm, Gp = 5 mm, Gl = 2.5 mm, Gw = 2 mm.

[0045] like Figure 6 As shown, the gap structure parameters of the present invention are: D = 25.9 mm, Dn = 21.9 mm, D1 = 15.5 mm, Dk = 1.3 mm, Dc = 6.6 mm, Ck = 0.8 mm, Cl = 1.2 mm, Xiw = 1.8 mm, Xik = 0.7 mm, Xil = 2.4 mm, Xil1 = 1.6 mm, Xil2 = 1 mm.

[0046] The working principle of the three-dimensional metasurface of the present invention is as follows: 1. The gap between the upper and lower layers forms two parallel LC resonant circuits, forming a passband in the frequency range of 3.3-3.8GHz; 2. The cross-shaped metal strips of the upper and lower layers are electrically connected to the vertical metal surface to form an LC series resonant circuit, generating a zero point, which effectively improves the suppression in the stopband frequency range of 1.4-2.69GHz; 3. The gap on the vertical metal surface provides a zero point, which improves the suppression in the stopband frequency range of 0-1GHz.

[0047] The proposed three-dimensional metasurface is designed to operate in the frequency band of 3.3-3.8 GHz. Figure 7The transmission characteristic curves of the three-dimensional metasurface proposed in this invention under the condition of normal incidence of spatial electromagnetic waves show that the average insertion loss is less than 0.23dB in the passband frequency range of 3.3-3.8GHz, the stopband rejection ratio is greater than 20dB in the stopband frequency range of 0-1GHz, and the stopband rejection ratio is greater than 16.3dB in the stopband frequency range of 1.4-2.69GHz.

[0048] Figure 8 The curves showing the influence of different electromagnetic wave incident angles on the proposed three-dimensional metasurface in TE mode reveal that as the angle increases, the suppression in the stopband frequency ranges of 0-1 GHz and 1.4-2.69 GHz increases, while the insertion loss in the passband frequency range of 3.3-3.8 GHz increases. Specifically, under the condition of 60-degree oblique incidence of spatial electromagnetic waves, the average insertion loss in the TE mode is less than 0.95 dB in the passband frequency range of 3.3-3.8 GHz, the stopband suppression is greater than 20 dB in the stopband frequency range of 0-1 GHz, and the stopband suppression is greater than 24 dB in the stopband frequency range of 1.4-2.69 GHz.

[0049] Figure 9 The curves showing the influence of different electromagnetic wave incident angles on the proposed three-dimensional metasurface in TM mode reveal that as the angle increases, the suppression in the stopband frequency ranges of 0-1 GHz and 1.4-2.69 GHz decreases, while the passband broadens in the 3.3-3.8 GHz range and the insertion loss remains essentially unchanged. Specifically, under the condition of 60-degree oblique incidence of spatial electromagnetic waves, the average insertion loss in the TM mode is less than 0.18 dB in the passband frequency range of 3.3-3.8 GHz, the stopband suppression is greater than 18.5 dB in the 0-1 GHz range, and the stopband suppression is greater than 15 dB in the 1.4-2.69 GHz range.

[0050] This invention provides an electromagnetic decoupling structure for a 5.5G communication system based on a three-dimensional metasurface with high out-of-band suppression. Under normal incidence of spatial electromagnetic waves, the average insertion loss of TE and TM modes is less than 0.23dB in the passband frequency range of 3.3-3.8GHz, the stopband suppression is greater than 20dB in the stopband frequency range of 0-1GHz, and the stopband suppression is greater than 16.3dB in the stopband frequency range of 1.4-2.69GHz. Under 60-degree oblique incidence of electromagnetic waves in space, the TE mode exhibits an average insertion loss of less than 0.95 dB in the passband frequency range of 3.3–3.8 GHz, a stopband rejection ratio of greater than 20 dB in the stopband frequency range of 0–1 GHz, and a stopband rejection ratio of greater than 24 dB in the stopband frequency range of 1.4–2.69 GHz. The TM mode exhibits an average insertion loss of less than 0.18 dB in the passband frequency range of 3.3–3.8 GHz, a stopband rejection ratio of greater than 18.5 dB in the stopband frequency range of 0–1 GHz, and a stopband rejection ratio of greater than 15 dB in the stopband frequency range of 1.4–2.69 GHz. Compared to existing metasurface structures, these technologies offer advantages such as low passband insertion loss, high stopband rejection ratio, fast roll-off, and good angular stability, thus possessing significant application value in mobile communication fields such as multi-band antenna decoupling.

[0051] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Obviously, those skilled in the art, after understanding the content and principles of the present invention, may make various modifications and changes in form and details without departing from the principles and structure of the invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. An electromagnetic decoupling structure for a 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface, characterized in that, It is composed of multiple identical periodic units arranged and spliced ​​together. Each periodic unit includes an upper antenna layer, an intermediate vertical layer and a lower antenna layer. The upper antenna layer and the lower antenna layer are connected by multiple intermediate vertical layers. The upper antenna layer includes an upper cross-shaped metal strip (1), an upper dielectric substrate (2), and an upper metal layer; the upper and lower surfaces of the upper dielectric substrate (2) are respectively covered with the upper cross-shaped metal strip (1) and the upper metal layer, and an upper gap (3) is opened in the upper metal layer. The upper gap (3) divides the upper metal layer into an upper inner metal layer and an upper outer metal layer. Mounting holes are opened around the upper dielectric substrate (2) at the upper outer metal layer. The upper end of each intermediate vertical layer is embedded in the corresponding mounting hole. Each branch end of the upper cross-shaped metal strip (1) is electrically connected to the upper end of the corresponding intermediate vertical layer, and the upper outer metal layer is electrically connected to the upper end of each intermediate vertical layer. The lower antenna layer includes a lower cross-shaped metal strip (8), a lower dielectric substrate (7), and a lower metal layer. The lower and upper surfaces of the lower dielectric substrate (7) are respectively covered with the lower cross-shaped metal strip (8) and the lower metal layer. A lower gap (6) is opened in the lower metal layer. The lower gap (6) divides the lower metal layer into an inner lower metal layer and an outer lower metal layer. Mounting holes are opened around the lower dielectric substrate (7) at the outer lower metal layer. The upper end of each intermediate vertical layer is embedded in the corresponding mounting hole. Each branch end of the lower cross-shaped metal strip (8) is electrically connected to the lower end of the corresponding intermediate vertical layer. The outer lower metal layer is electrically connected to the lower end of each intermediate vertical layer. The intermediate vertical layer includes a vertical dielectric plate (4), an upper vertical metal layer and a lower vertical metal layer; the upper and lower parts of one side of the vertical dielectric plate (4) are respectively covered with an upper vertical metal layer and a lower vertical metal layer, and an intermediate layer gap (5a) is provided between the upper vertical metal layer and the lower vertical metal layer. The upper vertical metal layer is electrically connected to the upper antenna layer, and the lower vertical metal layer is electrically connected to the lower antenna layer.

2. The electromagnetic decoupling structure for a 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface according to claim 1, characterized in that, In the adjacent periodic units, the upper outer metal layers of the upper metal layer are interconnected; in the adjacent periodic units, the lower outer metal layers of the lower metal layer are interconnected.

3. The electromagnetic decoupling structure for a 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface according to claim 1, characterized in that, The upper and lower metal layers are symmetrical and both have a square shape.

4. The electromagnetic decoupling structure for a 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface according to claim 1, characterized in that, The shape of the intermediate layer gap (5a) can be arbitrary.

5. The electromagnetic decoupling structure for a 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface according to claim 1, characterized in that, The shape of the intermediate layer gap (5a) is a straight line, a broken line, or a curve.

6. The electromagnetic decoupling structure for a 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface according to claim 1, characterized in that, The upper dielectric substrate (2) and the lower dielectric substrate (7) are made of F4B material with a dielectric constant of 3 and a dielectric loss tangent of 0.

001.

7. The application of the electromagnetic decoupling structure for a 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface according to claim 1, characterized in that, The application of the electromagnetic decoupling structure of the 5.5G communication system based on a high-inhibition-degree three-dimensional metasurface in the decoupling of multi-band antennas.

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