A protective antenna based on metasurface

Abstract

The application belongs to the technical field of antennas and relates to a super-surface-based protective antenna, which comprises a dielectric layer, a radiation layer arranged on the upper surface of the dielectric layer, a floor layer arranged on the lower surface of the dielectric layer and a feeding assembly; the radiation layer comprises a plurality of radiation patches arranged in a rectangular array to form a super surface with the length direction parallel or perpendicular to the length direction of the dielectric layer; along the length direction or the width direction of the super surface, one diode is arranged between any two adjacent radiation patches; when the super surface receives normal signals, the diode is in an off state; when the super surface receives electromagnetic attacks, the diode is in an on state; the electromagnetic protection of the antenna is realized through the state switching of the diode. The application has the advantages of wide working frequency band, high tolerance power, low insertion loss and high integration.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and in particular to a protective antenna based on metasurfaces. Background Technology

[0002] In recent years, with the advancement of electronic technology, radio frequency (RF) front-end links have been continuously developing towards miniaturization and integration. Various devices have different rated operating power, inevitably leading to mutual interference and increasingly severe electromagnetic compatibility (EMC) issues. Coupled with the threat of strong electromagnetic pulses in the future electromagnetic spectrum, the need for RF front-end protection is becoming increasingly urgent. However, traditional energy-selective protection technologies are still mainly applied by adding them before or after the antenna, rather than integrating them with the antenna, which leads to insufficient compatibility. To further improve the compatibility of protection with the original antenna, it is necessary to study integrated design methods for energy-selective protection functions and antennas.

[0003] In the existing technology, there is relatively little publicly available research on protective antennas. The main ideas include: achieving main lobe nulling by phase defocusing the reflector, achieving protection by loading the feed structure, and achieving resonant frequency shift reconstruction by loading the radiating resonant structure.

[0004] However, existing technologies each have their drawbacks: for reflector-type defocused protection antennas, their protection is spatially selective, with good protection only in the main lobe direction and a narrow bandwidth; for protection antennas loaded with feed structures, they have the problem of insufficient power tolerance; and for resonant reconfigurable protection antennas, the main problem is the narrow bandwidth. Summary of the Invention

[0005] Therefore, it is necessary to provide a protective antenna based on metasurfaces to address the above-mentioned technical problems, which can simultaneously have the advantages of wide operating bandwidth, high power tolerance, low insertion loss, and high integration.

[0006] A protective antenna based on metasurface includes: a dielectric layer, a radiating layer disposed on the upper surface of the dielectric layer, a ground layer disposed on the lower surface of the dielectric layer, and a feeding assembly;

[0007] The radiating layer includes: a plurality of radiating patches arranged in a rectangular array to form a metasurface whose length direction is parallel or perpendicular to the length direction of the dielectric layer; a diode is provided between any two adjacent radiating patches along the length or width direction of the metasurface.

[0008] When the metasurface receives a normal signal, the diode is in the off state; when the metasurface receives an electromagnetic attack, the diode is in the on state; electromagnetic protection of the antenna is achieved by switching the state of the diode.

[0009] In one embodiment, a diode is disposed between any two adjacent radiating patches along the length or width direction of the metasurface, including:

[0010] Along the length of the metasurface, a diode is provided between any two adjacent radiating patches;

[0011] Alternatively, a diode may be disposed between any two adjacent radiating patches along the width direction of the metasurface.

[0012] In one embodiment, the center of the radiating layer coincides with the center of the upper surface of the dielectric layer.

[0013] In one embodiment, both the radiating patch and the dielectric layer are rectangular structures, and the length and width directions of the radiating patch are parallel to the dielectric layer.

[0014] In one embodiment, the ratio of the length of the radiating patch, the width of the radiating patch, and the distance between two adjacent radiating patches is 10:8:1.

[0015] In one embodiment, the number of rows and columns of the metasurface are equal, and the distance between any adjacent radiating patches is equal.

[0016] In one embodiment, the power supply assembly includes: a coaxial connector and a rectangular probe disposed in the dielectric layer;

[0017] The outer conductor of the coaxial connector is connected to the ground plane, and the inner conductor passes through the ground plane, is inserted into the dielectric layer, and is connected to the rectangular probe, so that the power supply assembly forms an "L" shaped structure.

[0018] The length direction of the rectangular probe is consistent with the conduction direction of the diode, so as to excite a leakage radiation mode along the conduction direction of the diode on the surface of the radiation layer.

[0019] In one embodiment, the rectangular probe is positioned on one axis of symmetry of the radiating layer and passes through the center of the radiating layer.

[0020] In one embodiment, the length of the rectangular probe is equal to the sum of the length of the radiating patch and the distance between two adjacent radiating patches.

[0021] In one embodiment, the dielectric layer includes: a first dielectric substrate and a second dielectric substrate;

[0022] The radiation layer is disposed on the upper surface of the first dielectric plate, the floor layer is disposed on the lower surface of the second dielectric plate, and the rectangular probe is disposed between the first dielectric plate and the second dielectric plate.

[0023] The aforementioned metasurface-based protective antenna incorporates a radiating layer and a feeding assembly, integrating energy selection protection with the metasurface antenna radiating structure. This design applies protective functionality to the metasurface radiating structure, achieving electromagnetic protection by suppressing antenna radiation modes under strong fields. It ensures consistent polarization direction, expands the range of electrical dimensions, and simultaneously excites single-node and multi-node resonances, exciting radiation modes at different frequencies. This improves the operating bandwidth and power tolerance, while reducing insertion loss. Therefore, it simultaneously possesses the advantages of wide operating bandwidth, high power tolerance, low insertion loss, high protection efficiency, and high integration. Attached Figure Description

[0024] Figure 1 A side view of a metasurface-based protective antenna in one embodiment;

[0025] Figure 2 This is a top view of a metasurface-based protective antenna in one embodiment;

[0026] Figure 3 This is a side view of the dimensions of a metasurface-based protective antenna in one embodiment;

[0027] Figure 4 This is a top view of a metasurface-based protective antenna in one embodiment;

[0028] Figure 5 This is a diagram showing the dimensions of a rectangular probe for a metasurface-based protective antenna in one embodiment.

[0029] Figure 6 This is an equivalent transmission line model diagram of a metasurface-based protective antenna in one embodiment;

[0030] Figure 7 The dispersion map is shown for a metasurface-based protective antenna in one embodiment.

[0031] Figure 8 This is a reflection coefficient diagram of a metasurface-based protective antenna in one embodiment;

[0032] Figure 9 This is a comparison of the main lobe gain of a metasurface-based protective antenna in one embodiment;

[0033] Figure 10 This is a top view of a metasurface-based protective antenna in one embodiment;

[0034] Figure 11 A bottom view of a physical metasurface-based protective antenna in one embodiment;

[0035] Figure 12 This is a top view of a probe of a metasurface-based protective antenna in one embodiment;

[0036] Figure 13 This is a time-domain waveform diagram of a protective antenna based on a metasurface in one embodiment;

[0037] Figure 14 This is a comparison of simulation and actual measurement of the protective performance of a metasurface-based protective antenna in one embodiment.

[0038] Figure label:

[0039] Dielectric layer 1, first dielectric substrate 11, second dielectric substrate 12;

[0040] Radiation layer 2, radiation patch 21, diode 22;

[0041] Floor layer 3;

[0042] Power supply component 4, coaxial connector outer conductor 41, coaxial connector inner conductor 42, rectangular probe 43, solder 44, through hole 45. 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 protective antenna based on metasurfaces, such as... Figure 1 and Figure 2 (Where the arrows indicate the direction of electric field polarization) As shown, in one embodiment, it includes: a dielectric layer, a radiating layer, a ground layer, and a power supply assembly.

[0049] The dielectric layer serves as a load-bearing component, providing loading space for the radiating layer and the floor layer.

[0050] The radiating layer, a radiating component, is located on the upper surface of the dielectric layer and includes multiple radiating patches and multiple diodes. The radiating patches are arranged in a rectangular array to form a metasurface, the length direction of which is parallel or perpendicular to the length direction of the dielectric layer. Diodes are positioned between any two adjacent radiating patches along the length or width direction of the metasurface. Specifically, one diode is positioned between any two adjacent radiating patches along the length direction of the metasurface, or between any two adjacent radiating patches along the width direction of the metasurface. The diodes can be PIN diodes.

[0051] The floor layer is a grounding component, located on the lower surface of the dielectric layer, and is a fully covered floor.

[0052] The power supply component is a power supply part.

[0053] In this embodiment, the diode is in the off state when the metasurface receives a normal signal; the diode is in the on state when the metasurface receives an electromagnetic attack; electromagnetic protection of the antenna is achieved by switching the state of the diode.

[0054] Preferably, the center of the radiating layer coincides with the center of the upper surface of the dielectric layer, so that the direction of the main lobe of the antenna is perpendicular to the radiating structure and the symmetry of the antenna radiation pattern is guaranteed.

[0055] More preferably, both the radiating patch and the dielectric layer are rectangular structures, and the length and width directions of the radiating patch are parallel to the dielectric layer to form a standard radiation pattern and ensure a good radiation pattern.

[0056] More preferably, the ratio of the length of the radiating patch, the width of the radiating patch, and the distance between two adjacent radiating patches is 10:8:1. This ensures that the length of the radiating patch and the distance between two adjacent radiating patches achieve the matching frequency range of the antenna, while the width of the radiating patch and the distance between two adjacent radiating patches achieve the frequency range of the high-gain characteristics of the antenna pattern. These factors work together to ensure the operating frequency bands of both the longitudinal leakage radiation mode and the lateral field distribution mode of the antenna, enabling the antenna to simultaneously possess antenna performance with a large operating bandwidth and a high-gain pattern within that bandwidth.

[0057] More preferably, the number of rows and columns of the metasurface are equal, and the distance between any adjacent radiating patches is equal, so as to improve the consistency of the main lobe width of the antenna E-plane and H-plane radiation patterns, and the more periods there are, the narrower the main lobe width in this direction.

[0058] In another embodiment, the power supply assembly includes a coaxial connector and a rectangular probe; the outer conductor of the coaxial connector is connected to the ground plane, and the inner conductor passes through the ground plane and is inserted into the dielectric layer and connected to the rectangular probe, so that the power supply assembly forms an "L" shaped structure; the rectangular probe is disposed in the dielectric layer, and its length direction is consistent with the conduction direction of the diode, so as to excite a leakage radiation mode along the conduction direction of the diode on the surface of the radiation layer.

[0059] Preferably, the rectangular probe is positioned on one axis of symmetry of the radiating layer and passes through the center of the radiating layer to ensure the symmetry of the feed, avoid the offset of the antenna main lobe direction, and avoid changes in the antenna operating frequency band and radiation pattern.

[0060] More preferably, the length of the rectangular probe is equal to the sum of the length of the radiating patch and the distance between two adjacent radiating patches, in order to take into account the capacitance effect at the probe terminal, so that the distance from the vertical feed point to the probe terminal of the rectangular probe is 1 / 4 wavelength. After passing through the radiating structure of 4 unit cycles, the TM10 leaky wave mode field distribution of the radiating structure in the probe direction is a complete wavelength, thus achieving better matching characteristics.

[0061] In another embodiment, the dielectric layer includes a first dielectric substrate and a second dielectric substrate; a radiating layer is disposed on the upper surface of the first dielectric substrate, a ground layer is disposed on the lower surface of the second dielectric substrate, and a rectangular probe is disposed between the first and second dielectric substrates. This arrangement enables matching between the probe and the transmission line portion. Furthermore, due to the inherent broadband characteristics of the metasurface's periodic structure, matching with the radiating structure via probe-coupled feeding (rather than slot feeding or direct probe connection to the feed) achieves broadband matching characteristics, avoiding limitations on the antenna's operating bandwidth.

[0062] Preferably, a through hole is provided on the first dielectric plate at the position corresponding to the connection between the coaxial connector and the rectangular probe, so that the solder at the connection between the coaxial connector (e.g., SMA adapter) and the rectangular probe is placed in the through hole, thereby ensuring the fit between the first dielectric plate and the second dielectric plate after soldering and making the electrical connection more stable.

[0063] Note: Non-metallic studs (e.g., nylon studs) are provided at the four corners of the medium layer and the floor layer to connect and fix the parts into a whole.

[0064] In this application, the antenna operates as follows: At the feed port, a back-feed SMA connector is inserted from the back of the metal ground, and electrical connection to a rectangular probe is achieved through welding. Subsequently, it is coupled to the radiating layer via an L-shaped probe, radiating into free space. Based on this antenna, a diode is applied to the metasurface. When a normal operating signal is transmitted to the antenna, and the diode is off, the dispersion pattern of the radiating structure unit shows no significant change, allowing normal transmission to the feed port. The TM10 leakage radiation mode is normally excited on the surface of the radiating layer (not perpendicular to it), and the wave radiates normally along the diode connection direction parallel to the metasurface, enabling normal signal transmission and reception. When a strong electromagnetic wave irradiates the antenna, and the diode conducts, the electromagnetic energy is reflected, and the TM10 transmission mode is cut off. By disrupting the antenna's radiation mode, signals cannot be transmitted or received, and transmission to the feed port is impossible, thus achieving adaptive protection.

[0065] From the perspective of impedance, after adding the diode, since the diode itself has a small capacitance, the operating frequency is still much lower than the resonant frequency. Therefore, adding the diode does not affect the normal operation performance of the antenna. When the antenna is in the protection state, the diode is equivalent to a small resistor and no longer meets the impedance matching requirement, thus achieving protection.

[0066] From the perspective of radiation modes, the antenna can excite the TM10 leak mode, which can couple electromagnetic energy with free space for propagation.

[0067] The aforementioned metasurface-based protective antenna incorporates a radiating layer and a feeding assembly, integrating energy selection protection with the metasurface antenna radiating structure. This design applies protective functionality to the metasurface radiating structure, achieving electromagnetic protection by suppressing antenna radiation modes under strong fields. It ensures consistent polarization direction, expands the range of electrical dimensions, and simultaneously excites single-node and multi-node resonances, exciting radiation modes at different frequencies. This improves the operating bandwidth and power tolerance, while reducing insertion loss. Therefore, it simultaneously possesses the advantages of wide operating bandwidth, high power tolerance, low insertion loss, high protection efficiency, and high integration.

[0068] In one specific embodiment, the antenna's size parameters are as follows: Figure 3 , Figure 4 , Figure 5 As shown in Table 1.

[0069] Table 1: Antenna Dimensions

[0070]

[0071] The above antenna was simulated.

[0072] A transmission line unit model and an equivalent lumped circuit model are established for the radiating structure of the metasurface (with gaps containing diodes), resulting in the equivalent transmission line model diagram shown below. Figure 6 As shown, let the length of the transmission line unit in the x-direction be Δx = px, and the equivalent series capacitance per unit length be C. L The equivalent lumped capacitance per unit length and the equivalent series resistance R formed by the slot structure loaded between the radiating patches. L The equivalent lumped resistance of the gap as a radiating load, and the equivalent series inductance per unit length L R The equivalent lumped inductance and equivalent parallel capacitance per unit length C for the radial patch structure. R This is the equivalent capacitance formed by the radiating patch and the metal ground. Under normal operating conditions, the PIN diode is equivalent to a capacitor C. off At this time, the complex propagation constant γ of the antenna off With almost no change, it can normally generate leakage radiation mode to transfer energy into free space; in the protected state, the PIN diode is equivalent to a small resistor Ron. Since the resistance is very small and can be ignored, the propagation constant tends to 0. At this time, the antenna can hardly radiate normally, thus achieving strong electromagnetic protection function.

[0073] After simulation analysis, the results are as follows: Figures 7 to 9 As shown.

[0074] like Figure 7The dispersion diagram of the shielded antenna shows the propagation constant characteristics of the antenna's radiating structure in the x-direction. When the dispersion curve is lower than that of light, it means that the mode cannot radiate. Under normal operating conditions, the dispersion curve is above the light source in the 4.18-5.8 GHz range, allowing for normal radiation. Under shielded conditions, the dispersion curve is entirely below the light source, preventing normal radiation within the same frequency range.

[0075] like Figure 8 The reflection coefficient diagram of the protective antenna is shown below. Figure 9 The comparison diagram of the main lobe gain of the shielded antenna shows that the operating frequency band (4.5-6GHz) of the shielded antenna becomes a bandgap after the diode is turned on, and it is impossible to transmit or receive signals. In the shielded state, the reflection coefficient increases significantly while the gain decreases significantly. Therefore, the loading of the diode can suppress the radiation mode.

[0076] The above antenna was tested in practice.

[0077] like Figures 10 to 12 The antenna diagram shown illustrates the use of a high-power microwave source with a frequency of 5.8 GHz and a pulse width of 30 ns for irradiation. The field strength at the antenna aperture location is approximately 19440 V / m. Both a protective antenna and a control antenna were used for receiving the field strength. An attenuator and detector were connected to a transmission oscilloscope to compare the signal strength received by the protective and control antennas. The measured time-domain waveform of the protective antenna is shown below. Figure 13 As shown in the figure, the received signal is significantly attenuated when a protective antenna is used, with an attenuation value of approximately 21 dB; the comparison between the simulation and actual measurement of the protective effectiveness is shown in the figure below. Figure 14 As shown, the actual measurements are basically consistent with the simulation predictions.

[0078] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0079] 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.

[0080] 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 metasurface-based protective antenna, characterized in that, The application relates to an antenna, which comprises a medium layer, a radiation layer arranged on the upper surface of the medium layer, a floor layer arranged on the lower surface of the medium layer, and a feeding assembly. The radiation layer comprises a plurality of radiation patches arranged in a rectangular array to form a metasurface with the length direction parallel or perpendicular to the length direction of the medium layer; and a diode arranged between any two adjacent radiation patches along the length direction or the width direction of the metasurface. When the metasurface receives a normal signal, the diode is in an off state, a TM10 leaky-wave radiation mode is excited on the surface of the radiation layer, and the wave is normally radiated along the diode connection direction parallel to the metasurface; when the metasurface receives an electromagnetic attack, the diode is in an on state, electromagnetic energy is reflected, the TM10 transmission mode is cut off, and the radiation mode of the antenna is destroyed; and the electromagnetic protection of the antenna is realized through the state switching of the diode. The feeding assembly comprises a coaxial connector and a rectangular probe arranged in the medium layer. The outer conductor of the coaxial connector is connected with the floor layer, the inner conductor penetrates through the floor layer, is inserted into the medium layer, and is connected with the rectangular probe, so that the feeding assembly forms an "L" shaped structure. The length direction of the rectangular probe is consistent with the on direction of the diode, so that a leaky-wave radiation mode along the on direction of the diode is excited on the surface of the radiation layer. A diode is arranged between any two adjacent radiation patches along the length direction or the width direction of the metasurface, which comprises:

2. The metasurface-based protective antenna of claim 1, wherein, A diode is arranged between any two adjacent radiation patches along the length direction of the metasurface. Or, a diode is arranged between any two adjacent radiation patches along the width direction of the metasurface. The center of the radiation layer is consistent with the center of the upper surface of the medium layer.

3. The metasurface-based protective antenna according to claim 1 or 2, characterized in that, The radiation patch and the medium layer are both rectangular structures, and the length direction and the width direction of the radiation patch are both parallel to the medium layer.

4. The metasurface-based protective antenna of claim 3, wherein, The ratio of the length of the radiation patch, the width of the radiation patch, and the distance between two adjacent radiation patches is 10:8:

1.

5. The metasurface-based protective antenna of claim 4, wherein, The number of rows of the metasurface is equal to the number of columns, and the distance between any adjacent radiation patches is equal.

6. The metasurface-based protective antenna of claim 1 or 2, wherein, The rectangular probe is arranged on one symmetry axis of the radiation layer and passes through the center of the radiation layer.

7. The metasurface-based protective antenna of claim 1 or 2, wherein, The length of the rectangular probe is equal to the sum of the length of the radiation patch and the distance between two adjacent radiation patches.

8. The metasurface-based protective antenna of claim 7, wherein, The medium layer comprises a first medium plate and a second medium plate.

9. The metasurface-based protective antenna of claim 8, wherein, The radiation layer is arranged on the upper surface of the first medium plate, the floor layer is arranged on the lower surface of the second medium plate, and the rectangular probe is arranged between the first medium plate and the second medium plate. ​

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