A miniaturized metasurface unit and metasurface antenna based on patch stacking

Abstract

The application belongs to the technical field of metasurfaces, and relates to a miniaturized metasurface unit based on patch stacking and a metasurface antenna. The miniaturized metasurface unit based on patch stacking comprises a plurality of sequentially stacked dielectric layers, each of which comprises a dielectric plate, and the side lengths of all the dielectric plates are equal; the bottom of the lowermost dielectric plate is provided with a ground plate, and the top of each of the other dielectric plates is provided with two symmetrically and spaced-apart radiation patches, and the length direction of a slot line formed between the two radiation patches of the same dielectric layer is perpendicular to the direction of an incident wave electric field. The application can realize miniaturization and portability of an L wave band.

Description

Technical Field

[0001] This application relates to the field of metasurface technology, and in particular to a miniaturized metasurface unit and metasurface antenna based on patch stacking. Background Technology

[0002] In recent years, radar systems and wireless communication systems have developed rapidly in the microwave frequency band. Mobile communication requires low-cost, high-capacity communication terminals to expand the coverage of communication access services, while radar detection requires low latency and high-precision beam control to extract target features in complex electromagnetic environments.

[0003] Among them, parabolic antennas are bulky, phased array antennas are expensive, and their feeding networks are complex. Passive planar array antennas have fixed structures and their electromagnetic characteristics cannot be changed. They can only achieve angle-limited beam scanning by changing the relative position of the feed source and the antenna.

[0004] Currently, electrically tunable and reconfigurable metasurfaces have become a research hotspot due to their advantages of low cost, low latency, and flexible beam control.

[0005] In the existing technology, various reconfigurable metasurfaces have been proposed to date, enabling electromagnetic wave manipulation from the visible light band to terahertz waves. Among them, the 1-bit reconfigurable metasurface integrating a PIN diode has been widely used.

[0006] However, since the size of the antenna is approximately proportional to the wavelength, conventional low-frequency metasurfaces cannot achieve a trade-off between array size and the number of array elements, which limits the accuracy and angular range of the corresponding beam scanning. Simultaneously, excessively large element periods worsen the phase error related to the element spacing under oblique incidence conditions, resulting in degraded oblique incidence performance. Therefore, reducing the size of low-frequency reconfigurable metasurface antennas is of great significance for the integrated and miniaturized design of mobile communication terminals and satellite navigation modules. Summary of the Invention

[0007] Therefore, it is necessary to provide a miniaturized metasurface unit and metasurface antenna based on patch stacking to address the above-mentioned technical problems, which can achieve miniaturization and portability in the L-band.

[0008] A miniaturized metasurface unit based on patch stacking includes: multiple dielectric layers stacked sequentially, each dielectric layer including a dielectric plate, and all dielectric plates having equal side lengths;

[0009] The bottom of the lowest dielectric plate has a floor, and the top of the other dielectric plates has two symmetrically spaced radiating patches. The length of the groove line formed between the two radiating patches in the same dielectric layer is perpendicular to the direction of the incident wave electric field.

[0010] In one embodiment, the following layers are stacked sequentially from top to bottom: a first dielectric layer, a second dielectric layer, a third dielectric layer, and a fourth dielectric layer.

[0011] The first dielectric layer includes: a first dielectric substrate and a first radiating patch;

[0012] The second dielectric layer includes: a second dielectric substrate and a second radiating patch;

[0013] The third dielectric layer includes: a third dielectric substrate and a third radiating patch;

[0014] The fourth dielectric layer includes: a fourth dielectric plate and a floor;

[0015] The first radiating patch is the same size as the second radiating patch, but different in size from the third radiating patch.

[0016] In one embodiment, a first groove is provided between two first radiating patches, a second groove is provided between two second radiating patches, and a third groove is provided between two third radiating patches.

[0017] The dimensions of the first, second, and third grooves are all the same.

[0018] In one embodiment, an air layer is provided between the first dielectric layer and the second dielectric layer, between the second dielectric layer and the third dielectric layer, and between the third dielectric layer and the fourth dielectric layer.

[0019] In one embodiment, the thickness of each air layer increases sequentially from top to bottom.

[0020] In one embodiment, the third dielectric layer further includes a diode;

[0021] The two ends of the diode are each connected to a third radiating patch.

[0022] In one embodiment, the third dielectric layer further includes: four bias lines;

[0023] Two of the bias lines are located at the two ends of a third radiating patch and are collinear, while the other two bias lines are located at the two ends of another third radiating patch and are collinear.

[0024] The four bias lines are all perpendicular to the direction of the incident wave electric field and are arranged symmetrically.

[0025] In one embodiment, the third dielectric substrate is made of a material with a dielectric constant value in the range of 10-16.

[0026] A metasurface antenna includes: multiple miniaturized metasurface units based on patch stacking;

[0027] Multiple miniaturized metasurface unit arrays based on patch stacking are configured.

[0028] In one embodiment, the diodes in different miniaturized metasurface units based on patch stacks have different on / off states to achieve 1-bit beam scanning.

[0029] The aforementioned miniaturized metasurface unit based on patch stacking incorporates multiple stacked dielectric layers, introduces capacitive loading, and employs a high-dielectric-constant material for the third dielectric substrate. This significantly increases the equivalent capacitance of the metasurface unit, thereby substantially reducing the resonant frequency of the active metasurface to the L-band. Utilizing the resonant characteristics, the required phase difference for a 1-bit L-band metasurface is achieved, resulting in a 22% relative bandwidth, while simultaneously reducing the unit size to 0.1λ. By designing individual radiating patches and placing them along the polarization direction of each input mode, the unit can adapt to linearly polarized antenna feeds with different port input modes, effectively reducing the metasurface unit size. Furthermore, the design of PIN diodes further enhances the miniaturization of the metasurface unit under corresponding linear polarization conditions. Miniaturization; by designing bias lines, the signal is input through the bias lines, and the direction of the bias lines is perpendicular to the electric field, thereby minimizing the interference between the bias signal and the air-fed electromagnetic wave, realizing miniaturized metasurface units; by setting the bias lines on the third radiating patch in a direction perpendicular to the incident electric field, the array composed of these metasurface units can adjust the voltage of the metal plates on both sides in this direction through external voltage, thereby realizing column control of the diode bias state; this application solves the problems of excessive size of low-frequency active metasurface units, limited array beam scanning effect, and inconvenient antenna design. While maintaining broadband characteristics, it effectively realizes L-band miniaturization design, and has a simple structure, is easy to process, has a small size, and a low profile, which can be mass-produced.

[0030] The aforementioned metasurface antenna is designed with an array of metasurface elements. The third radiating patch of each metasurface element is connected to adjacent metasurface elements via a bias line to achieve column control. The bias line facilitates the connection of different elements and enables control of the array bias. By controlling the on / off state of the PIN diodes, the phase response of the elements is adjusted, enabling the 1-bit metasurface element to satisfy a 180° phase difference within a certain bandwidth in both on and off states. This achieves both wide impedance bandwidth and miniaturization, making it possible to achieve low-frequency miniaturization of active elements while maintaining wide bandwidth performance. This application realizes a broadband L-band 1-bit miniaturized metasurface element and a miniaturized single-beam array metasurface antenna, which has broad application prospects in UAV communication, mobile communication, and wireless sensing. Furthermore, the miniaturization of the L-band can further revolutionize sensing devices and communication terminals, which is of great significance. Attached Figure Description

[0031] Figure 1This is a three-dimensional schematic diagram of a miniaturized metasurface unit based on patch stacking in one embodiment;

[0032] Figure 2 This is a top view of a third dielectric layer in a miniaturized metasurface unit based on patch stacking in one embodiment.

[0033] Figure 3 This is a dimensional diagram of a miniaturized metasurface unit based on patch stacking in one embodiment;

[0034] Figure 4 Another dimension view of a miniaturized metasurface unit based on patch stacking in one embodiment;

[0035] Figure 5 This is a simulation result diagram of the reflection phase of a miniaturized metasurface unit based on patch stacking in one embodiment;

[0036] Figure 6 This is a simulation result of the reflection amplitude of a miniaturized metasurface unit based on patch stacking in one embodiment.

[0037] Figure label:

[0038] First dielectric substrate 11, first radiating patch 12, first groove line 13;

[0039] Second dielectric substrate 21, second radiating patch 22, second groove line 23;

[0040] Third dielectric substrate 31, third radiating patch 32, third groove line 33, diode 34, bias line 35;

[0041] Fourth medium plate 41, floor 42;

[0042] Air layer 5. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0044] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0045] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple sets" means at least two sets, such as two sets, three sets, etc., unless otherwise explicitly specified.

[0046] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0047] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0048] This application provides a miniaturized metasurface unit based on patch stacking, comprising: multiple dielectric layers stacked sequentially, each dielectric layer including a dielectric plate, all dielectric plates having equal side lengths; the bottom of the lowest dielectric plate has a ground plane, and the top of each of the other dielectric plates has two symmetrically spaced radiating patches, the length direction of the groove line formed between the two radiating patches of the same dielectric layer is perpendicular to the direction of the incident wave electric field.

[0049] like Figure 1 and Figure 2 As shown, in one embodiment, it includes a first dielectric layer, a second dielectric layer, a third dielectric layer, and a fourth dielectric layer, and the first dielectric layer, the second dielectric layer, the third dielectric layer, and the fourth dielectric layer are stacked sequentially from top to bottom.

[0050] The first dielectric layer includes: a first dielectric substrate and a first radiating patch; two first radiating patches are symmetrically spaced on the top of the first dielectric substrate, and a first groove is formed between the two first radiating patches.

[0051] The second dielectric layer includes a second dielectric substrate and a second radiating patch; two second radiating patches are symmetrically spaced at the top of the second dielectric substrate, and a second groove is formed between the two second radiating patches.

[0052] The third dielectric layer includes: a third dielectric substrate, a third radiating patch, a diode, and bias lines; two third radiating patches are symmetrically spaced on the top of the third dielectric substrate, and a third groove is formed between the two third radiating patches; the diode is located at the center of the third dielectric substrate, oriented in the same direction as the incident electric field, that is, each end of the diode is connected to a third radiating patch; there are four bias lines, two of which are located at the ends of one third radiating patch and are collinear, and the other two are located at the ends of another third radiating patch and are collinear, and the directions of all four bias lines are perpendicular to the direction of the incident electric field and are symmetrically arranged.

[0053] The fourth medium layer includes a fourth medium board and a floor; the floor is located at the bottom of the fourth medium board and is the same size as the fourth medium board, that is, the floor is a full-coverage floor.

[0054] Preferably, the first radiating patch and the second radiating patch have the same size, but the size of the third radiating patch is different. Specifically, the first, second, and third radiating patches have a rectangular structure to utilize large-size patches and achieve a low resonant frequency unit design through a relatively simple structure.

[0055] More preferably, the first groove, the second groove, and the third groove are all the same size and are all located on the axis of symmetry of the corresponding dielectric plates. That is, the first groove is located on the axis of symmetry of the first dielectric plate, the second groove is located on the axis of symmetry of the second dielectric plate, and the third groove is located on the axis of symmetry of the third dielectric plate.

[0056] More preferably, the third dielectric substrate is made of a material with a dielectric constant value in the range of 10-16.

[0057] It should be noted that the first radiating patch, the second radiating patch, the third radiating patch, the bias line, and the floor are all made of metal materials, while the first dielectric plate, the second dielectric plate, the third dielectric plate, and the fourth dielectric plate are all made of non-metallic materials.

[0058] In one embodiment, support columns are provided between the first dielectric layer and the second dielectric layer, between the second dielectric layer and the third dielectric layer, and between the third dielectric layer and the fourth dielectric layer, so that air layers are formed between the first dielectric layer and the second dielectric layer, between the second dielectric layer and the third dielectric layer, and between the third dielectric layer and the fourth dielectric layer, so as to reduce processing costs and physical weight while ensuring low profile characteristics and improving design portability.

[0059] Preferably, the thickness of each air layer increases sequentially from top to bottom to enhance the phase modulation effect between the third and fourth dielectric layers.

[0060] The aforementioned miniaturized metasurface unit based on patch stacking incorporates multiple stacked dielectric layers, introduces capacitive loading, and employs a high-dielectric-constant material for the third dielectric substrate. This significantly increases the equivalent capacitance of the metasurface unit, thereby substantially reducing the resonant frequency of the active metasurface to the L-band. Utilizing the resonant characteristics, the required phase difference for a 1-bit L-band metasurface is achieved, resulting in a 22% relative bandwidth, while simultaneously reducing the unit size to 0.1λ. By designing individual radiating patches and placing them along the polarization direction of each input mode, the unit can adapt to linearly polarized antenna feeds with different port input modes, effectively reducing the metasurface unit size. Furthermore, the design of PIN diodes further enhances the miniaturization of the metasurface unit under corresponding linear polarization conditions. Miniaturization; by designing bias lines, the signal is input through the bias lines, and the direction of the bias lines is perpendicular to the electric field, thereby minimizing the interference between the bias signal and the air-fed electromagnetic wave, realizing miniaturized metasurface units; by setting the bias lines on the third radiating patch in a direction perpendicular to the incident electric field, the array composed of these metasurface units can adjust the voltage of the metal plates on both sides in this direction through external voltage, thereby realizing column control of the diode bias state; this application solves the problems of excessive size of low-frequency active metasurface units, limited array beam scanning effect, and inconvenient antenna design. While maintaining broadband characteristics, it effectively realizes L-band miniaturization design, and has a simple structure, is easy to process, has a small size, and a low profile, which can be mass-produced.

[0061] This application also provides a metasurface antenna, which in one embodiment includes: a plurality of miniaturized metasurface units based on patch stacking, and an array of the plurality of miniaturized metasurface units based on patch stacking.

[0062] Different on / off states of diodes in miniaturized metasurface units based on patch stacking are used to achieve 1-bit beam scanning.

[0063] Specifically, a PIN diode is used as the diode, and the resonant frequency of the metasurface unit is determined by the equivalent capacitance and equivalent inductance, as expressed by the following formula:

[0064]

[0065] In the formula, f is the resonant frequency of the unit cell, and L... eq The equivalent inductance value of a unit cell can be changed by adjusting the thickness of the dielectric layers (specifically including the thickness of the first, second, third, and / or fourth dielectric layers) and the relative positions between the patches (specifically referring to the relative positions between the first, second, and third radiating patches). C eqThe equivalent capacitance value of a unit is determined by changing the number of layers of the patches (including: the first radiating patch, the second radiating patch, or the third radiating patch) and adjusting the size of the patches, thereby enhancing or weakening the patch capacitive coupling effect and affecting the unit equivalent capacitance value.

[0066] The working size of the antenna is approximately proportional to the wavelength, and according to the resonance characteristics, the phase changes drastically near the resonant frequency. Therefore, by changing the size of the patch and adjusting the thickness of the air layer and the dielectric layer, the capacitance and inductance values ​​of the equivalent circuit can be changed, and the resonant frequency corresponding to the two states of diode on and off can be adjusted, thereby achieving a 180° phase difference over a wide bandwidth.

[0067] The aforementioned metasurface antenna is designed with an array of metasurface elements. The third radiating patch of each metasurface element is connected to adjacent metasurface elements via a bias line to achieve column control. The bias line facilitates the connection of different elements and enables control of the array bias. By controlling the on / off state of the PIN diodes, the phase response of the elements is adjusted, enabling the 1-bit metasurface element to satisfy a 180° phase difference within a certain bandwidth in both on and off states. This achieves both wide impedance bandwidth and miniaturization, making it possible to achieve low-frequency miniaturization of active elements while maintaining wide bandwidth performance. This application realizes a broadband L-band 1-bit miniaturized metasurface element and a miniaturized single-beam array metasurface antenna, which has broad application prospects in UAV communication, mobile communication, and wireless sensing. Furthermore, the miniaturization of the L-band can further revolutionize sensing devices and communication terminals, which is of great significance.

[0068] like Figure 3 and Figure 4 As shown, in a specific embodiment, 20*20 miniaturized metasurface units based on patch stacking form a metasurface antenna. The side length of the dielectric layer in each metasurface unit is p = 21 mm, corresponding to an electrical dimension of approximately 0.1λ, where λ is the wavelength of 214 mm at the center frequency of 1.4 GHz. The length of the first and second radiating patches is L1 = 20 mm, and the width is W1 = 9.85 mm. The length of the first and second slot lines is L1 = 20 mm, and the width is W = 0.3 mm. The length of the third radiating patch is L2 = 20 mm, and the width is W2 = 8.35 mm. The length of the third slot line is L2 = 20 mm, and the width is W = 0.3 mm. The length of the bias line is L3 = 1 mm, and the width is W3 = 0.5 mm. The first, second, and fourth dielectric plates are all made of FR4 material (εr = 2.65, tanδ = 0.002) with a thickness of 1 mm. The third dielectric plate is made of TP1020, a high dielectric material, with a thickness of 2.6 mm. The thicknesses of the air layers from top to bottom are 1.3 mm, 2.3 mm, and 2.8 mm, respectively.

[0069] Simulation analysis was performed on the aforementioned miniaturized metasurface unit based on patch stacking, and the results are as follows: Figure 5 and Figure 6 As shown.

[0070] The metasurface antenna designed based on the above 1-bit metasurface unit can achieve good beam scanning performance in the L-band bandwidth of 1.2GHz-1.6GHz, realize a broadband 180° phase difference in two states, has high beam scanning accuracy, is easy to integrate and portable, and has low cost.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A miniaturized metasurface unit based on patch stacking, characterized by, Comprise: a plurality of sequentially stacked dielectric layers, each dielectric layer comprising a dielectric plate, all dielectric plates having equal side lengths; the bottom of the lowermost dielectric plate is provided with a floor, and the top of each other dielectric plate is provided with two symmetrically spaced radiation patches, the length direction of the slot line formed between the two radiation patches of the same dielectric layer is perpendicular to the incident wave electric field direction; comprise from top to bottom sequentially: the first dielectric layer, the second dielectric layer, the third dielectric layer and the fourth dielectric layer; the first dielectric layer comprises: a first dielectric plate and a first radiation patch; the second dielectric layer comprises: a second dielectric plate and a second radiation patch; the third dielectric layer comprises: a third dielectric plate and a third radiation patch; the fourth dielectric layer comprises: a fourth dielectric plate and a floor; the third dielectric layer further comprises: a diode; both ends of the diode are connected to a third radiation patch respectively; the third dielectric layer further comprises: four bias lines; two bias lines are arranged at both ends of one third radiation patch and are collinear, and the other two bias lines are arranged at both ends of the other third radiation patch and are collinear; The direction of the four bias lines is perpendicular to the incident wave electric field direction, and they are symmetrically arranged.

2. The miniaturized metasurface unit based on patch stacking according to claim 1, wherein the size of the first radiation patch and the second radiation patch is the same, and the size of the third radiation patch is different.

3. The patch stack-based miniaturized metasurface unit of claim 2, wherein, a first slot line is arranged between two first radiation patches, a second slot line is arranged between two second radiation patches, and a third slot line is arranged between two third radiation patches; the size of the first slot line, the second slot line and the third slot line is the same.

4. A patch stack-based miniaturized metasurface unit according to claim 2 or 3, characterized in that, air layers are arranged between the first dielectric layer and the second dielectric layer, between the second dielectric layer and the third dielectric layer, and between the third dielectric layer and the fourth dielectric layer.

5. The patch stack-based miniaturized metasurface unit of claim 4, wherein, The thickness of each air layer increases from top to bottom.

6. A patch stack-based miniaturized metasurface unit according to any one of claims 1 to 3, characterized in that, The third dielectric plate is made of a material with a dielectric constant value in the range of 10-16.

7. A metasurface antenna, characterized in that, Comprise: a plurality of miniaturized metasurface units based on patch stacking according to any one of claims 1 to 6; a plurality of miniaturized metasurface unit arrays based on patch stacking are arranged.

8. The metasurface antenna of claim 7, wherein, The on-off state of the diode in different miniaturized metasurface units based on patch stacking is different to realize 1bit beam scanning.

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