Frequency-agile absorption and transmission integrated electromagnetic metasurface and antenna housing

Abstract

The invention belongs to the technical field of multifunctional radomes, and particularly relates to a frequency-agile absorption and transmission integrated electromagnetic metasurface and radome, the frequency-agile absorption and transmission integrated electromagnetic metasurface comprises a plurality of basic units in periodic array distribution, and each basic unit comprises a wave transmission layer and a wave absorption layer which are oppositely arranged; the wave-transparent layer comprises a wave-transparent dielectric substrate, a wave-transparent metal foil layer I and a wave-transparent metal foil layer II, wherein the wave-transparent metal foil layer I and the wave-transparent metal foil layer II are arranged on the two sides of the wave-transparent dielectric substrate. The wave-transparent metal foil layer I comprises a plurality of metal spiral lines, the wave-transparent metal foil layer II comprises a metal foil, and the metal foil is provided with an annular gap and rectangular gaps distributed around the annular gap; the wave-absorbing layer comprises a wave-absorbing dielectric substrate, and a wave-absorbing metal foil layer I and a wave-absorbing metal foil layer II which are arranged on two sides of the wave-absorbing dielectric substrate; according to the invention, the wave-transparent communication and wave-absorbing isolation functions are realized at the same time, the wave-absorbing frequency band agility function is realized, and the wave-absorbing effect is better.

Description

Technical Field

[0001] The present invention belongs to the technical field of multifunctional antenna covers, and specifically relates to a frequency-agile, absorbent and penetrating integrated electromagnetic metasurface and an antenna cover. Background Art

[0002] The antenna at the front end of modern wireless communication and radar systems is an indispensable component of the entire system. The new multifunctional electromagnetic metamaterial antenna cover provides physical protection for the covered antenna, preventing it from being affected by bad weather such as rain and snow; at the same time, it provides electromagnetic protection, allowing the covered antenna to communicate freely without loss within its own communication frequency band, and to achieve isolation from the external electromagnetic environment in the absorbing frequency band, that is, in the absorbing frequency band outside the antenna communication frequency band, it is difficult for external electromagnetic waves to interfere with or detect the covered antenna.

[0003] Frequency agility of electromagnetic metamaterials refers to the ability of the material to dynamically adjust its operating frequency and quickly switch between different frequency bands to absorb or transmit electromagnetic waves to meet the needs of complex electromagnetic environments. Its core mechanism is based on the reconfigurability of electromagnetic metamaterials. It changes the electromagnetic parameters of the material (such as dielectric constant and magnetic permeability) through external excitation or intelligent control methods to achieve response adjustment to specific frequencies. Achieving frequency agility can better adapt to the needs of dynamic electromagnetic environments, improve anti-interference and concealment, and optimize wide-band performance. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a frequency-agile electromagnetic metasurface and antenna cover that has both wave-transmitting communication and wave-absorbing isolation functions, and has the function of agile wave-absorbing frequency band change, resulting in better wave-absorbing effect.

[0005] The embodiment of the present invention provides a frequency-agile electromagnetic metasurface with absorption and penetration, comprising a plurality of basic units distributed in a periodic array, wherein the basic unit comprises two wave-transmitting layers and a wave-absorbing layer arranged opposite to each other; The wave-transmitting layer comprises a wave-transmitting medium substrate and a wave-transmitting metal foil layer I and a wave-transmitting metal foil layer II arranged on both sides of the wave-transmitting medium substrate; The wave-transmitting metal foil layer I is a plurality of metal spirals, and the wave-transmitting metal foil layer II comprises a metal foil, and the metal foil is provided with an annular gap and rectangular gaps distributed around the annular gap; The wave absorbing layer comprises a wave absorbing medium substrate and a wave absorbing metal foil layer I and a wave absorbing metal foil layer II arranged on both sides of the wave absorbing medium substrate; The wave-absorbing metal foil layer I comprises a closed-loop metal wire I, on which a plurality of resonant structures I are arranged, and the resonant structure I comprises a connecting wire I connected to the closed-loop metal wire I and an open metal wire connected to the connecting wire I; a variable capacitance diode is arranged on the connecting wire I and / or the open metal wire; The absorbing metal foil layer II includes a closed-loop metal wire II, on which a plurality of resonant structures II are arranged, and the resonant structure II includes a connecting wire II connected to the closed-loop metal wire II and a U-shaped metal wire connected to the connecting wire II; a variable capacitance diode is arranged on the connecting wire II, and a resistor is arranged on the U-shaped metal wire.

[0006] Preferably, there is air between the wave-transmitting layer and the wave-absorbing layer.

[0007] Preferably, the wave-transmitting layer and the wave-absorbing layer are rectangular, and the closed-loop metal wire I and the closed-loop metal wire II are rectangular.

[0008] Preferably, the number of the metal spiral lines is 4, and the array is distributed on the surface of the wave-transmitting medium substrate, and the metal spiral lines are rectangular path spiral structures.

[0009] Preferably, the annular gap is in a rectangular shape.

[0010] Preferably, the closed-loop metal wire I and the closed-loop metal wire II are rectangular, the number of the resonant structures I is 4 and they are respectively located on the four sides of the closed-loop metal wire I, and the number of the resonant structures II is 4 and they are respectively located on the four sides of the closed-loop metal wire II.

[0011] Preferably, the open metal wire is a rectangle with an opening, and the opening is close to the center of the closed-loop metal wire I.

[0012] Preferably, a varactor diode is provided on the connecting line I.

[0013] Preferably, a connecting through hole is provided on the absorbing medium substrate, and the connecting through hole connects and conducts the open metal wire and the U-shaped metal wire.

[0014] An embodiment of the present invention provides a radome, comprising the frequency-agile, absorbent and penetrating integrated electromagnetic metasurface.

[0015] The beneficial effect of the present invention is that the present invention organically combines the wave-transmitting communication metamaterial structure and the wave-absorbing isolation metamaterial structure to form an integrated multifunctional antenna cover structure. By using the printed circuit board process loaded with varactor diodes and lumped resistors, the wave-absorbing frequency band can be changed quickly, so that the metamaterial antenna cover can effectively cope with the complex electromagnetic environment with variable frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of Example 1 of the present invention.

[0017] Figure 2 This is a schematic diagram of the structure of the wave-transmitting metal foil layer I of Example 1 of the present invention.

[0018] Figure 3This is a schematic diagram of the structure of the wave-transmitting metal foil layer II of Example 1 of the present invention.

[0019] Figure 4 Schematic diagram of the structure of the absorbing metal foil layer I of Example 1 of the present invention.

[0020] Figure 5 Schematic diagram of the structure of the absorbing metal foil layer II of Example 1 of the present invention.

[0021] Figure 6 is the transmission coefficient of the structure of Example 1 of the present invention.

[0022] Figure 7 is the reflection coefficient of the structure of Example 1 of the present invention.

[0023] Figure 8 This is the transmission / reflection characteristic of the structure of Example 1 of the present invention.

[0024] Fig. 9 This is the transmission / reflection characteristic of the structure of comparative example 1 of the present invention.

[0025] Fig.10 1 and 2 are the transmission / reflection characteristics of the structure of comparative example 2 of the present invention.

[0026] Fig.11 1 and 2 are the transmission / reflection characteristics of the structure of comparative example 3 of the present invention.

[0027] Fig.12 1 and 2 show the transmission / reflection characteristics of the structure of comparative example 4 of the present invention.

[0028] In the figure, 1 is a wave-transmitting layer, 11 is a wave-transmitting metal foil layer I, 111 is a metal spiral line, 12 is a wave-transmitting dielectric substrate, 13 is a wave-transmitting metal foil layer II, 131 is a metal foil, 132 is an annular gap, and 133 is a rectangular gap; 2 absorbing layer, 21 absorbing metal foil layer I, 211 closed-loop metal wire I, 212 connecting wire I, 213 opening metal wire, 2131 connecting through hole, 2132 opening, 214 varactor diode, 22 absorbing medium substrate; 23 absorbing metal foil layer II, 231 closed-loop metal wire II, 232 connecting wire II, 233 U-shaped metal wire, 234 resistor. DETAILED DESCRIPTION

[0029] Example 1 like Figure 1-5 As shown, a frequency-agile electromagnetic metasurface with absorption and penetration, including a plurality of basic units distributed in a periodic array, wherein the basic unit includes two wave-transmitting layers 1 and a wave-absorbing layer 2 arranged opposite to each other; The wave-transmitting layer 1 comprises a wave-transmitting medium substrate 12 and a wave-transmitting metal foil layer I 11 and a wave-transmitting metal foil layer II 13 arranged on both sides of the wave-transmitting medium substrate 12; The wave-transmitting metal foil layer I11 is a plurality of metal spirals 111, and the wave-transmitting metal foil layer II13 includes a metal foil 131, and the metal foil 131 is provided with an annular gap 132 and rectangular gaps 133 distributed around the annular gap 132; The absorbing layer 2 includes an absorbing medium substrate 22 and an absorbing metal foil layer I 21 and an absorbing metal foil layer II 23 arranged on both sides of the absorbing medium substrate 22; The wave-absorbing metal foil layer I21 includes a closed-loop metal wire I211, on which a plurality of resonant structures I are arranged, and the resonant structure I includes a connecting wire I212 connected to the closed-loop metal wire I211 and an open metal wire 213 connected to the connecting wire I212; and a variable capacitance diode 214 (the number is 4) is arranged on the connecting wire I212; The absorbing metal foil layer II23 includes a closed-loop metal wire II231, on which a plurality of resonant structures II are arranged, and the resonant structure II includes a connecting wire II232 connected to the closed-loop metal wire II231 and a U-shaped metal wire 233 connected to the connecting wire II232; a varactor diode 214 is arranged on the connecting wire II232 (that is, after the connecting wire II232 is cut off, the varactor diode 214 is placed at the cut-off position and connected to the cut-off connecting wire II232, and the number is 4), and a resistor 234 is arranged on the U-shaped metal wire 233 (that is, after the U-shaped metal wire 233 is cut off, the resistor 234 is placed at the cut-off position and connected to the cut-off U-shaped metal wire 233, and the resistor 234 is arranged on two U-shaped arms of the U-shaped metal wire 233, the number of U-shaped metal wires 233 is 4, and the total number of resistors 234 is 8).

[0030] The wave-transmitting layer 1 of the present invention realizes a wave-transmitting function, and the wave-absorbing layer 2 realizes a wave-absorbing function. Both the wave-transmitting layer 1 and the wave-absorbing layer 2 are prepared by using a printed circuit board process.

[0031] The wave-transmitting dielectric substrate 12 and the wave-absorbing dielectric substrate 22 are both made of insulating materials, with a thickness of 0.3 to 1 mm and a relative dielectric constant of 2.2 to 6. The material of the metal foil can be gold foil or copper foil.

[0032] There is air between the wave-transmitting layer 1 and the wave-absorbing layer 2, and the distance between the two is 5 to 20 mm.

[0033] The wave-transmitting layer 1 and the wave-absorbing layer 2 are rectangular, and the closed-loop metal wire I 211 and the closed-loop metal wire II 231 are rectangular, preferably square.

[0034] The number of the metal spiral lines 111 is 4, and the array is distributed on the surface of the wave-transmitting medium substrate 12. The metal spiral lines 111 are rectangular path spiral structures, that is, they are formed by bending a plurality of fold lines at 90° to each other into a rectangle, the length of the rectangle is 3mm to 6mm, the width is 2mm to 5mm, and the line width is 0.1mm to 0.5mm.

[0035] The annular gap 132 is rectangular, preferably square, and has a length of 1 to 5 mm. The rectangular gap 133 has a length of 2 to 5 mm and a width of 1 to 5 mm.

[0036] The closed-loop metal wire I 211 and the closed-loop metal wire II 231 are rectangular, the number of the resonant structures I is 4, which are respectively located on the four sides of the closed-loop metal wire I 211 , and the number of the resonant structures II is 4, which are respectively located on the four sides of the closed-loop metal wire II 231 .

[0037] The open metal wire 213 is a rectangle having an opening 2132 , and the opening 2132 is close to the center of the closed-loop metal wire I 211 .

[0038] A variable capacitance diode 214 is disposed on the connecting line I 212 .

[0039] The absorbing medium substrate 22 is provided with a connecting through hole 2131, and the connecting through hole 2131 connects and conducts the open metal wire 213 and the U-shaped metal wire 233. The conduction means that the open metal wire 213 and the U-shaped metal wire 233 are electrically connected, which can be achieved by using a metal through hole. Preferably, the connecting through hole 2131 connects and conducts the end of the open metal wire 213 and the end of the U-shaped metal wire 233, and the diameter of the connecting through hole 2131 is 0.1 mm to 0.5 mm.

[0040] The closed-loop metal wire I 211 and the closed-loop metal wire II 231 are square, and the side lengths thereof are the same as the side lengths of the wave-transmitting medium substrate 12 and the wave-absorbing medium substrate 22 .

[0041] The wave-transmitting metal foil layer Ⅰ11 and the wave-absorbing metal foil layer Ⅱ23 of the present invention are arranged opposite to each other.

[0042] The wave-transmitting medium substrate 12 and the wave-absorbing medium substrate 22 are square, and the side length is 5 mm to 20 mm.

[0043] The width of the metal spiral wire 111, the closed-loop metal wire I211, the connecting wire I212, the open metal wire 213, the closed-loop metal wire II231, the connecting wire II232, and the U-shaped metal wire 233 is 0.1-0.5 mm. The thickness of the wave-transmitting metal foil layer I11, the wave-transmitting metal foil layer II13, the wave-absorbing metal foil layer I21, and the wave-absorbing metal foil layer II23 is 0.017 mm to 0.035 mm.

[0044] The open metal line 213 is a rectangle with an opening 2132, and has a length of 3 mm to 8 mm and a width of 0.5 mm to 2 mm. The width of the opening is 0.5 mm to 1 mm, and the line width is 0.1 mm to 0.5 mm.

[0045] The capacitance value of the varactor diode 214 varies in the range of 0.2 pF to 1 pF, the inductance value is 0.3 nH to 1 nH, and the parasitic resistance value is 5 Ω to 20 Ω. The resistance value of the resistor 234 is 100 Ω to 500 Ω.

[0046] An embodiment of the present invention provides a radome, comprising the frequency-agile, absorbent and penetrating integrated electromagnetic metasurface.

[0047] Example 2 The transmission coefficient of the structure of Example 1 was measured and the results were as follows: Figure 6 As shown by Figure 6 It can be seen that when the capacitance value of the varactor diode 214 changes from 0.3pF to 0.9pF in a step of 0.1pF, its wave transmission frequency band ( ) remain unchanged, both are 15.54GHz to 17.25GHz.

[0048] The reflection coefficient of the structure of Example 1 was measured and the result was as follows: Figure 7 As shown by Figure 7 It can be seen that when the capacitance value of the varactor diode 214 changes from 0.3pF to 0.9pF in a step of 0.1pF, its absorption frequency band ( ) changes from 13.65GHz to 12.97GHz, then to 12.72GHz, then to 12.45GHz, then to 12.29GHz, and finally to 12.11GHz. It can be seen that when the capacitance value is small, the absorption frequency band changes greatly when the capacitance value changes by 0.1pF.

[0049] Comparative Example 1 On the basis of Example 1, the metal spiral wire 111 and the rectangular gap 133 of the wave-transmitting layer 1 are removed, and the other structures remain the same as those of Example 1.

[0050] Comparing the transmission / reflection characteristics of the structures of Example 1 (i.e., structural unit 00) and Comparative Example 1 (i.e., structural unit 01), it is obtained that Figure 8-9 .

[0051] from Figure 8-9It can be seen that adding the structural unit of the rectangular slit and the metal spiral line will not increase any cost. However, at the high frequency end of the wave absorption band, from the S parameters near the frequency points marked in the figure, the wave absorption effect of Example 1 is better. In the wave absorption band, the rectangular slit and the metal spiral line are combined to form a series resonance, which works together with the series resonance formed by the annular slit to make more electromagnetic waves incident on the wave-transmitting layer 1 reflected back to the wave-absorbing layer 2. Thus, it is better absorbed by the wave-absorbing layer 2.

[0052] Comparative Examples 2-3 On the basis of Example 1, the resistor 234 is not provided on the U-shaped metal wire 233 , and correspondingly, eight resistors 234 are provided on the open metal wire 213 , and the open metal wire 213 is a rectangle with an opening.

[0053] Specifically, eight resistors 234 are arranged on the edge where the opening of the open metal line 213 is located, and other structures remain the same as those in Example 1, which is Comparative Example 2 (ie, structural unit 02).

[0054] Specifically, eight resistors 234 are arranged on the long side of the open metal line 213 close to the connection line I 212 , and other structures remain the same as those in Example 1, which is Comparative Example 3 (ie, structural unit 03 ).

[0055] The transmission / reflection characteristics of the structure of Comparative Example 2-3 were measured, and the results were Figure 10-11 .

[0056] As can be seen from the figure, the open metal wires 213 of Comparative Examples 2 and 3 are both disconnected to bridge the resistor, and the length of the metal wire of the open metal wire 213 becomes shorter, so that only the incident electromagnetic waves with a higher frequency band than the original absorption frequency band can be sensed. Therefore, the absorption frequency bands of these two structural units move toward the transmission frequency band, resulting in the disappearance of the transmission frequency band of the structure of Example 1. Figure 10-11 The frequency points marked in , does not meet the requirements of the wave transmission band.

[0057] Comparative Example 4 The four varactor diodes 214 on the absorbing metal foil layer Ⅰ21 are removed, and the two ends of the four varactor diodes 214 are connected together with metal foil. The other structures remain the same as those in the first embodiment.

[0058] The transmission / reflection characteristics of the structure of Comparative Example 4 were measured, and the results were Fig.12 .

[0059] Comparative Example 4 contains a varactor diode 214 only on the absorbing metal foil layer II 23. When the capacitance value of the varactor diode 214 is adjusted, the adjustment range is 0.2pF to 1pF. Fig.12The wave absorption characteristics of this structure can be seen. In the frequency band around 10GHz, when the capacitance value changes, the frequency band does not change, only the degree of wave absorption changes.

[0060] A person skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0061] One or more embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the present application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A frequency-agile absorption-penetration integrated electromagnetic metasurface, characterized in that: It comprises a plurality of basic units distributed in a periodic array, wherein the basic unit comprises two wave-transmitting layers (1) and a wave-absorbing layer (2) arranged opposite to each other; The wave-transmitting layer (1) comprises a wave-transmitting medium substrate (12) and a wave-transmitting metal foil layer I (11) and a wave-transmitting metal foil layer II (13) arranged on both sides of the wave-transmitting medium substrate (12); The wave-transmitting metal foil layer I (11) is a plurality of metal spirals (111), and the wave-transmitting metal foil layer II (13) comprises a metal foil (131), wherein the metal foil (131) is provided with an annular gap (132) and rectangular gaps (133) distributed around the annular gap (132); The wave absorbing layer (2) comprises a wave absorbing medium substrate (22) and a wave absorbing metal foil layer I (21) and a wave absorbing metal foil layer II (23) arranged on both sides of the wave absorbing medium substrate (22); The wave-absorbing metal foil layer I (21) comprises a closed-loop metal wire I (211), on which a plurality of resonant structures I are arranged, and the resonant structures I comprise a connecting wire I (212) connected to the closed-loop metal wire I (211) and an open metal wire (213) connected to the connecting wire I (212); a variable capacitance diode (214) is arranged on the connecting wire I (212) and / or the open metal wire (213); The wave-absorbing metal foil layer II (23) comprises a closed-loop metal wire II (231), on which a plurality of resonant structures II are arranged, the resonant structures II comprising a connecting wire II (232) connected to the closed-loop metal wire II (231) and a U-shaped metal wire (233) connected to the connecting wire II (232); a variable capacitance diode (214) is arranged on the connecting wire II (232), and a resistor (234) is arranged on the U-shaped metal wire (233).

2. The supersurface according to claim 1, characterized in that: There is air between the wave-transmitting layer (1) and the wave-absorbing layer (2).

3. The supersurface according to claim 1, characterized in that: The wave-transmitting layer (1) and the wave-absorbing layer (2) are rectangular, and the closed-loop metal wire I (211) and the closed-loop metal wire II (231) are rectangular.

4. The supersurface according to any one of claims 1 to 3, characterized in that: The number of the metal spiral lines (111) is 4, and the array is distributed on the surface of the wave-transmitting medium substrate (12); the metal spiral lines (111) are rectangular path spiral structures.

5. The supersurface according to any one of claims 1 to 3, characterized in that: The annular gap (132) is in the shape of a rectangle.

6. The supersurface according to any one of claims 1 to 3, characterized in that: The closed-loop metal wire I (211) and the closed-loop metal wire II (231) are rectangular, the number of the resonant structures I is 4, and they are respectively located on the four sides of the closed-loop metal wire I (211), and the number of the resonant structures II is 4, and they are respectively located on the four sides of the closed-loop metal wire II (231).

7. The supersurface according to claim 6, characterized in that: The open metal wire (213) is a rectangle having an opening (2132), and the opening (2132) is close to the center of the closed-loop metal wire I (211).

8. The supersurface according to claim 6, characterized in that: A variable capacitance diode (214) is provided on the connecting line I (212).

9. The supersurface according to any one of claims 1 to 3, characterized in that: The absorbing medium substrate (22) is provided with a connecting through hole (2131), and the connecting through hole (2131) connects and conducts the open metal wire (213) and the U-shaped metal wire (233).

10. A radome, characterized in that: It comprises the frequency-agile, absorbent and penetrating integrated electromagnetic metasurface as described in any one of claims 1 to 9.

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