EP4632953A1

EP4632953A1 - Metasurface unit and metasurface system

Info

Publication number: EP4632953A1
Application number: EP24741153.1A
Authority: EP
Inventors: Weishuang YIN; Jianjun Wu; Yijun CUI; Kunjing ZHONG
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2023-01-12
Filing date: 2024-01-04
Publication date: 2025-10-15
Also published as: CN118336388A; KR20250117428A; WO2024149154A1; EP4632953A4

Abstract

The present application discloses a metasurface unit and a metasurface system. The metasurface unit comprises a dual-polarized metasurface radiation structure, a first-layer ground structure, an isolation structure, a second-layer ground structure, and a control structure which are sequentially arranged in different layers, wherein the dual-polarized metasurface radiation structure comprises a radiation patch; the control structure is connected to the radiation patch by means of a connecting path structure; the connecting path structure comprises two connecting pieces arranged in parallel; the two connecting pieces extend to the radiation patch from the layer where the isolation structure is located; the isolation structure comprises an isolation piece conductively connected in correspondence to each of the connecting pieces; and the isolation piece is used for reflecting radio frequency waves.

Description

Cross-Reference to Related Application

The present application claims priority to Chinese Patent Application No.202310074667.5, filed on January 12, 2023 , which is incorporated herein by reference in its entirety.

Technical Field

The present application relates to the technical field of communications, and in particular, to a metasurface unit and a metasurface system.

Background

Metasurfaces have been extensively studied due to their ability to efficiently and cost-effectively manipulate spatial electromagnetic waves. When transitioning from a single-polarization metasurface to a dual-polarization metasurface, issues such as polarization crosstalk, Alternating Current (AC)-Direct Current (DC) isolation, and surface waves may arise. Therefore, most existing research has focused on single-bit, single-polarization scenarios.
Currently, a symmetric design is generally employed to address polarization crosstalk between dual-polarization metasurfaces, but this may double the number of tunable devices. To address AC-DC isolation, a bias voltage is typically applied at a point where the dipole field is weakest, but this limits design flexibility. To mitigate surface wave crosstalk, cavities formed by through-holes are commonly used, but the effectiveness is poor in many cases.

Summary

Embodiments of the present application provide a metasurface unit and a metasurface system, which may solve the problem of polarization crosstalk and may achieve AC-DC isolation.
According to a first aspect of the embodiments of the present application, a metasurface unit is provided, including a dual-polarization metasurface radiation structure, a first-layer ground structure, an isolation structure, a second-layer ground structure, and a control structure which are sequentially arranged in layers, wherein

the dual-polarization metasurface radiation structure includes a radiation patch;
the control structure is connected to the radiation patch via a connection path structure, wherein the connection path structure includes two connection components arranged in parallel, and the two connection components extend at least from the layer where the isolation structure is located to the radiation patch; and
the isolation structure includes isolation pieces corresponding to and conductively connected to respective ones of the two connection components, and the isolation pieces are used for reflecting radio frequency waves.

According to a second aspect of the embodiments of the present application, a metasurface system is further provided. The metasurface system includes a plurality of metasurface units. The metasurface units each include a dual-polarization metasurface radiation structure, a first-layer ground structure, an isolation structure, a second-layer ground structure, and a control structure which are sequentially arranged in layers, wherein

the dual-polarization metasurface radiation structure includes a radiation patch;
the control structure is connected to the radiation patch via a connection path structure, wherein the connection path structure includes two connection components arranged in parallel, and the two connection components extend from the layer where the isolation structure is located to the radiation patch; and
the isolation structure includes isolation pieces corresponding to and conductively connected to respective ones of the two connection components, and the isolation pieces are used for reflecting radio frequency waves.

Brief Description of the Drawings

In order to describe the technical solutions in the embodiments of the present application or in the related art more clearly, accompanying drawings requiring to be used for describing the embodiments or the related art are introduced briefly as follows. Apparently, the accompanying drawings in the following description merely relate to some embodiments of the present application, and for those skilled in the art, other accompanying drawings may also be obtained according to the structures illustrated in these accompanying drawings without involving any inventive effort.

Fig. 1 is a schematic diagram of a metasurface system provided according to some embodiments of the present application;
Fig. 2 is a schematic side view of a metasurface unit provided according to some embodiments of the present application;
Fig. 3 is a logical topology graph of the metasurface unit of Fig. 2;
Fig. 4 is a schematic side view of a metasurface unit provided according to some other embodiments of the present application;
Fig. 5 is a schematic perspective view of a metasurface unit provided according to still some other embodiments of the present application;
Fig. 6 is a side view of the structure of the metasurface unit of Fig. 5;
Fig. 7 is a schematic exploded perspective view of Fig. 5;
Fig. 8 is a top view of the structure of the metasurface unit of Fig. 5;
Fig. 9 is a schematic diagram of an isolation structure and a connection path structure of the metasurface unit of Fig. 5;
Fig. 10 is a schematic structural diagram of a radiation patch and mode adjustment structures of the metasurface unit of Fig. 5; and
Fig. 11 is a polarization isolation curve of the metasurface unit of Fig. 5.

Annotation and Component Identification in Figures:

Reference Sign	Name	Reference Sign	Name
100	Metasurface system	7	Connection path
100a	Metasurface unit	70	Main path
1	Dual-polarization metasurface radiation	71	Connection component
11	Radiation patch	72	Adaption component
2	First-layer ground structure	73	Connection branch
3	Isolation structure	8	Mode adjustment
30	Isolation piece	81	First branch
31	First isolation piece	82	Second branch
32	Second isolation piece	83	Switching device
4	Second-layer ground structure	9	Back cavity structure
5	Control structure	91	Metal frame
6	Third-layer ground structure	92	Conductive pillar

Implementation of the objects, and functional features and advantages of the present application are further described with reference to the accompanying drawings in combination with embodiments.

Detailed Description of the Embodiments

Hereinafter, the technical solutions in the embodiments of the present utility model will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the embodiments as described are only some of the embodiments of the present utility model, and are not all of the embodiments. All other embodiments obtained by those skilled in the art on the basis of the embodiments of the present utility model without involving any inventive effort shall all fall within the scope of protection of some embodiments of the present utility model.
It should be noted that, if the embodiments of the present utility model relate to a directivity indication (such as up, down, left, right, front, back,...), the directivity indication is only used for explaining a relative position relationship between components, a motion condition thereof, etc. in a certain specific posture (as shown in the accompanying drawings), and if the specific posture changes, the directivity indication changes accordingly.
In addition, if the embodiments of the present utility model relate to descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, features defined by "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and/or" appearing in the full text includes three parallel solutions. Taking "A and/or B" as an example, the solution includes solution A, solution B, or a solution satisfying both A and B. In addition, the technical solutions of the embodiments may be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of the technical solutions is contradictory or cannot be implemented, it should be considered that the combination of the technical solutions does not exist, and does not fall within the scope of protection of the present utility model.
Metasurfaces have been extensively studied due to their ability to efficiently and cost-effectively manipulate spatial electromagnetic waves. When transitioning from a single-polarization metasurface to a dual-polarization metasurface, issues such as polarization crosstalk, AC-DC isolation and surface waves may arise. Therefore, most existing research has focused on single-bit, single-polarization scenarios. In order to solve the problem of dual-polarization crosstalk, the embodiments of the present application provide a metasurface unit and a metasurface system. Fig. 1 shows a metasurface system provided according to some embodiments of the present application; and Figs. 2 to 8 show a metasurface unit provided according to some embodiments of the present application.
Please refer to Fig. 1, some embodiments of the present application provide a metasurface system 100, including a plurality of metasurface units 100a. In some embodiments of the present application, the plurality of metasurface units 100a are arranged in a matrix. Obviously, the design is not limited thereto. The specific arrangement method of the plurality of metasurface units 100a may be designed according to actual needs, and the specific number of the plurality of metasurface units 100a is also not limited.
Please refer to Fig. 2, Fig. 2 provides a schematic side view of a metasurface unit according to some embodiments of the present application. The metasurface unit 100a includes a dual-polarization metasurface radiation structure 1, a first-layer ground structure 2, an isolation structure 3, a second-layer ground structure 4, and a control structure 5 which are sequentially arranged in layers.
The dual-polarization metasurface radiation structure 1 includes a radiation patch 11; and the control structure 5 is connected to the radiation patch 11 via a connection path structure 7, wherein the connection path structure 7 includes two connection components 71 arranged in parallel, and the two connection components 71 at least extend from the layer where the isolation structure 3 is located to the radiation patch 11. The isolation structure 3 includes isolation pieces 30 corresponding to and conductively connected to respective ones of the two connection components 71, and the isolation pieces 30 are used for reflecting radio frequency waves.
In the technical solution of the embodiments of the present application, the connection path structure 7 is divided into two parallel connection components 71 between the isolation structure 3 and the radiation patch 11, and the isolation structure 3 is provided with isolation pieces 30 corresponding to respective ones of the two connection components 71, such that digital signals input from the control structure 5 to the dual-polarization metasurface radiation structure 1 enter the radiation patch 11 from the two connection components 71, respectively, and dual-polarization radio frequency signals coming from the radiation patch 11 are separated at the two connection components 71 and are reflected to the radiation patch 11 via the isolation pieces 30, respectively, so as to avoid mutual influence between the dual-polarization radio frequency signals, and prevent the radio frequency signals from being transmitted to the control structure 5 and affecting operation of the control structure 5. In this way, AC-DC isolation, i.e. isolation between a digital signal and a radio frequency signal, can be realized, and the problem of polarization crosstalk of a dual-polarization metasurface may be solved.
Please further refer to Fig. 2, in the embodiments of the present application, the connection path structure 7 further includes a main path 70, and one end of the main path 70 is connected to the control structure 5, and the other end of the main path 70 is connected to the two connection components 71. That is, one port may be provided on the control structure 5, and two polarizations are controlled via this port, thereby reducing the number of ports provided.
Please further refer to Fig. 3, Fig. 3 is a logical topology graph of the metasurface unit provided in Fig. 2. As illustrated in the schematic diagram, the metasurface unit 100a according to the embodiments of the present application uses a centralized (control structure 5)-distributed (two connection components 71)-centralized (radiation patch 11) control method.
Obviously, the connection path structure 7 is not necessarily provided with a main path 70. In some other embodiments of the present application, as shown in Fig. 4, in the embodiments, one end of each of the two connection components 71 extends to the control structure 5 so as to be directly connected to the control structure 5.
Figs. 5 to 11 show a metasurface unit according to still some other embodiments of the present application.
Please refer to Fig. 5, in some embodiments of the present application, the isolation structure 3 is divided into two layers to achieve isolation between the two layers. For details, reference can be made to the relevant description in the following part. Obviously, the design is not limited thereto. The isolation structure 3 may have one layer or two or more layers. In the embodiments, a third-layer ground structure 6 is provided on one side of the control structure 5 opposite to the second-layer ground structure 4, and the control structure 5 is electrically connected to the third-layer ground structure 6, so that the third-layer ground structure 6 implements ground protection for the layer where the control structure 5 is located.
In some embodiments, please refer to Fig. 6, Fig. 6 is a side view of Fig. 5. In Fig. 6, layering of the dual-polarization metasurface radiation structure 1, the first-layer ground structure 2, the isolation structure 3, the second-layer ground structure 4, the control structure 5 and the third-layer ground structure 6 is further illustrated. The isolation structure 3 is divided into two layers, and the two layers of the isolation structure 3 are respectively provided with first isolation pieces 31 and second isolation pieces 32. For details, reference can be made to the description in the following part.
Please refer to Fig. 7, in some embodiments of the present application, the isolation structure 3 includes first isolating pieces 31 and second isolating pieces 32 arranged in layers. The first isolation pieces 31 and the second isolation pieces 32 are used for reflecting the radio frequency waves, respectively. The first isolation pieces 31 and the second isolation pieces 32 may reflect radio frequency waves at the same frequency band, and may also reflect radio frequency waves at different frequency bands. Each of the two connection components 71 connects one of the first isolation pieces 31 and one of the second isolation pieces 32. By providing a plurality of layers (two layers) of isolation pieces 30, radio frequency waves may be better reflected, so as to better achieve AC-DC isolation.
Specifically, in some embodiments of the present application, the first separation piece 31 is arranged in a rectangular shape, and the second separation piece 32 is arranged in an arc shape. Obviously, the present application is not limited thereto. The first separation pieces 31 and the second separation pieces 32 may also be in other shapes, such as a polygon. Due to the difference in the shape and the area of the first separation pieces 31 and the second separation pieces 32, the reflected frequency band may also be different. Specifically, an adjustment may be made according to design requirements.
Please refer to Figs. 8 and 9, and also refer to Fig. 7, in some embodiments of the present application, the connection path structure 7 further includes an adaption component 72 disposed offset from the two connection components 71, and one end of the adaption component 72 is connected to the control structure 5, and the other end of the adaption component 72 is connected to the two connection components 71 via connection branches 73. In this way, the control structure 5 is connected to the two connection components 71 via the adaption component 72, such that the path between the control structure 5 and the isolation structure 3 can be extended, and thus the residual radio frequency signal obtained after the radio frequency signal from the radiation patch 11 passes through the isolation structure 3 can be further reduced and transmitted to the control structure 5.
Please refer to Fig. 10, in some embodiments of the present application, two mode adjustment structures 8 for correspondingly controlling two polarizations are provided at two side edges of the radiation patch 11, and each of the two mode adjustment structures 8 includes a first branch 81 connected to a peripheral side of the radiation patch 11, a second branch 82 connected to the first-layer ground structure 2, and a switching device 83 connecting the first branch 81 and the second branch 82. The electromagnetic response of the dual-polarization metasurface radiation structure 1 is adjusted by controlling the working mode of the dual-polarization metasurface radiation structure 1 by the switching device 83, such that the electromagnetic waves reflected by the dual-polarization metasurface radiation structure 1 may generate a phase difference. For example, in some embodiments of the present application, the phase difference is a phase difference of 180°. The specific structure of the switching device 83 is not limited, and may be one of a PIN tube, a varactor, a switch, an MEMS tube, and a non-transitory device.
Please refer to Figs. 5 and 7, in some embodiments of the present application, the first-layer ground structure 2 and the second-layer ground structure 3 are conductively connected via a plurality of conductive structures, so that an isolation cavity is defined between the first-layer ground structure 2 and the second-layer ground structure 3. The isolation structure 3 is disposed in the isolation cavity, so that coupling between units and a waveguide mode in an array (in cases where there are a plurality of metasurface units 100a arranged in an array in the metasurface system 100) can be inhibited.
Please refer to Figs. 5 and 7, in some embodiments of the present application, the metasurface unit 100a further includes a back cavity structure 9. The back cavity structure 9 is disposed on one side of the dual-polarization metasurface radiation structure 1, and the back cavity structure 9 is conductively connected to the first-layer ground structure 2, so as to define a back cavity in conjunction with the first-layer ground structure 2. In this way, coupling between units and a waveguide mode in an array (in cases where there are a plurality of metasurface units 100a arranged in an array in the metasurface system 100) can be inhibited.
In some embodiments of the present application, the back cavity structure 9 includes a metal frame 91 and a plurality of conductive pillars 92. The plurality of conductive pillars 92 are correspondingly connected to the metal frame 91, the first-layer ground structure 2 and the second-layer ground structure 4, so that the back cavity is defined between the metal frame 91 and the first-layer ground structure 2, and an isolation cavity is defined between the first-layer ground structure 2 and the second-layer ground structure 4. Both the back cavity and the isolation cavity can inhibit coupling between units and a waveguide mode in an array (in cases where there are a plurality of metasurface units 100a arranged in an array in the metasurface system 100). Furthermore, the plurality of conductive pillars 92 connect the first-layer ground structure 2 and the second-layer ground structure 4 at the same time, instead of respectively providing conductive pillars to connect the metal frame 91 and the first-layer ground structure 2. The embodiments of the present application use a method of sharing the conductive pillars 92 so as to connect the first-layer ground structure 2 and the second-layer ground structure 4, and the structure is simpler and easy to manufacture.
Please refer to Fig. 11, in some embodiments of the present application, Fig. 11 is an isolation curve diagram between two polarizations, and the degree of isolation of a unit within the entire frequency band of 26-28 GHz is higher than -15 dB.
The content above merely relates to exemplary embodiments of the present application and is not intended to limit the patent scope of the present application. Any equivalent structural change made by using the description and the accompanying drawings of the present application or direct/indirect application in other related technical fields under the concept of the present application is included in the patent scope of protection of the present application.

Claims

A metasurface unit, comprising a dual-polarization metasurface radiation structure, a first-layer ground structure, an isolation structure, a second-layer ground structure, and a control structure which are sequentially arranged in layers, wherein
the dual-polarization metasurface radiation structure comprises a radiation patch;

the control structure is connected to the radiation patch via a connection path structure, wherein the connection path structure comprises two connection components arranged in parallel, and the two connection components extend at least from the layer where the isolation structure is located to the radiation patch; and

the isolation structure comprises isolation pieces corresponding to and conductively connected to respective ones of the two connection components, and the isolation pieces are used for reflecting radio frequency waves.
The metasurface unit according to claim 1, wherein the isolation structure comprises first isolation pieces and second isolation pieces that are arranged in layers, and the first isolation pieces and the second isolation pieces are used for reflecting the radio frequency waves, respectively; and
each of the two connection components is connected to one of the first isolation pieces and one of the second isolation pieces.
The metasurface unit according to claim 1, wherein the connection path structure further comprises an adaption component disposed offset from the two connection components, and one end of the adaption component is connected to the control structure, and the other end of the adaption component is connected to the two connection components via connection branches.
The metasurface unit according to claim 1, wherein two mode adjustment structures for correspondingly controlling two polarizations are provided at two side edges of the radiation patch, and each of the two mode adjustment structures comprises a first branch connected to a peripheral side of the radiation patch, a second branch connected to the first-layer ground structure, and a switching device connecting the first branch and the second branch.
The metasurface unit according to claim 1, wherein the connection path structure further comprises a main path, and one end of the main path is connected to the control structure, and the other end of the main path is connected to the two connection components.
The metasurface unit according to claim 1, wherein the first-layer ground structure and the second-layer ground structure are conductively connected via a plurality of conductive structures, so that an isolation cavity is defined between the first-layer ground structure and the second-layer ground structure.
The metasurface unit according to claim 1, wherein the metasurface unit further comprises a back cavity structure, wherein the back cavity structure is disposed on one side of the dual-polarization metasurface radiation structure, and the back cavity structure is conductively connected to the first-layer ground structure, so as to define a back cavity in conjunction with the first-layer ground structure.
The metasurface unit according to claim 7, wherein the back cavity structure comprises:
a metal frame; and

a plurality of conductive pillars correspondingly connected to the metal frame, the first-layer ground structure and the second-layer ground structure, so that the back cavity is defined between the metal frame and the first-layer ground structure, and an isolation cavity is defined between the first-layer ground structure and the second-layer ground structure.
The metasurface unit according to claim 1, wherein the metasurface unit further comprises a third-layer ground structure disposed on one side of the control structure opposite to the second-layer ground structure.
A metasurface system, comprising a plurality of metasurface units according to any one of claims 1 to 9.