An integrated energy-selective metasurface for microwave absorption and protection

Abstract

This invention discloses an integrated energy-selective metasurface for electromagnetic shielding and absorption, belonging to the field of electromagnetic protection technology. It comprises a first substrate dielectric substrate, a first metal circuit structure printed on the upper surface of the first substrate dielectric substrate, a second metal circuit structure printed on the lower surface of the first substrate dielectric substrate, a second substrate dielectric substrate, and a third metal circuit structure printed on the upper surface of the second substrate dielectric substrate. The energy-selective metasurface of this invention exhibits energy selectivity in two frequency bands: 1.92GHz–2.05GHz and 4.40GHz–4.46GHz, allowing low-power signals to transmit while reflecting or blocking high-power electromagnetic energy; and achieves a broadband absorption effect with an absorption rate exceeding 95% in the X-band. This invention integrates multi-band energy-selective protection and broadband high-efficiency absorption functions into one device.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic protection technology, and more specifically to an integrated energy-selective metasurface for electromagnetic protection. Background Technology

[0002] With the rapid development of modern electronic information systems towards intelligence, integration, and miniaturization, equipment size continues to shrink while the density of electronic components increases significantly, leading to a sharp increase in the system's sensitivity to changes in surrounding electromagnetic fields, voltage, and current. Experimental studies have shown that electromagnetic pulses can penetrate into electronic systems through spatial radiation or cable coupling. When the coupling energy exceeds the damage threshold of sensitive components, it can cause component burnout, logic disorder, or even permanent system failure. In particular, intentional or unintentional attacks or radiation from high-frequency, high-power microwaves can damage critical electronic components under long-distance, non-contact conditions, causing the entire system to malfunction. How to ensure the safe and reliable operation of electronic information systems in complex electromagnetic environments has become a core issue that urgently needs to be addressed.

[0003] Current protection against strong electromagnetic threats mainly relies on "backdoor" protection technologies such as filtering, shielding, and grounding. While these methods are easy to implement at the circuit design level, they significantly increase system complexity and design difficulty. For the "front door" channel where electromagnetic energy directly intrudes, existing technologies generally adopt the solution of adding high-power limiters or attenuators at the front end. Although these can attenuate strong currents, they cause severe distortion of normal signals. If frequency selective surfaces (FSS) or bandpass filters are used for out-of-band isolation, their fixed operating frequency bands and lack of adaptive capabilities make them unable to cope with strong electromagnetic pulse threats within the passband.

[0004] Energy selective surfaces (ESS), as a cutting-edge protection technology based on the principle of field-induced nonlinear impedance transformation, achieve intelligent protection by adaptively adjusting the surface impedance characteristics: maintaining high transmittance in low-power states and instantly switching to a high-impedance shielding state when encountering strong electromagnetic excitation, with a response speed on the nanosecond level. However, existing ESS technologies still have significant shortcomings, mainly manifested in their limited functionality and lack of absorption mechanisms (reflective protection is prone to secondary electromagnetic coupling), making it difficult to meet the comprehensive needs of modern electronic equipment for multi-band composite protection and energy absorption. Currently, no publicly available literature reports energy selective surfaces with multi-band protection and X-band absorption capabilities.

[0005] Therefore, how to propose an energy-selective metasurface that integrates multi-band energy-selective protection with broadband high-efficiency wave absorption is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides an integrated energy selective metasurface for microwave absorption and protection, which has both multi-band adaptive protection performance and good X-band microwave absorption performance and compact structure.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An integrated energy-selective metasurface for microwave absorption and protection comprises multiple periodically arranged metasurface units;

[0009] The metasurface unit includes a first substrate dielectric substrate and a second substrate dielectric substrate arranged in parallel at certain intervals.

[0010] The upper surface of the first substrate dielectric substrate is printed with a first metal circuit structure, and the lower surface is printed with a second metal circuit structure; the upper surface of the second substrate dielectric substrate is printed with a third metal circuit structure.

[0011] The first metal circuit structure, the second metal circuit structure, and the third metal circuit structure are coaxial with the first substrate dielectric base; wherein, the first metal circuit structure and the second metal circuit structure are centrally symmetrical ring structures, the first metal circuit structure includes multiple right-angled metal zigzag structures connected by resistors, and the second metal circuit structure includes a metal plate with multiple hollowed-out zigzag structures; the third metal circuit structure includes a first square metal resonant ring structure and a second square metal resonant ring structure, both of which are C-shaped structures with openings formed by multiple metal microstrips, wherein the first square metal resonant ring structure forms a closed loop by a diode connected across the two ends of the opening, and the second square metal resonant ring structure forms a closed loop by a diode and a capacitor connected in parallel across the two ends of the opening.

[0012] Preferably, the right-angled metal zigzag structure includes two zigzag units, each of which includes five straight metal strips connected vertically in sequence, and the two zigzag units are connected end-to-end to form a symmetrical structure.

[0013] Preferably, the second metal circuit structure includes multiple hollow units, each hollow unit being a symmetrical structure, including a first right-angle hollow structure, two second right-angle hollow structures, and two straight hollow structures; the two second right-angle hollow structures are respectively disposed at both ends of the first right-angle hollow structure, and the other end of each second right-angle hollow structure is connected to one of the straight hollow structures;

[0014] The first right-angled hollow structure is a rectangular groove shape with an open top; the second right-angled hollow structure is an upward-facing right-angled broken line shape; the straight-line hollow structure is a straight line shape.

[0015] The hollowed-out units are vertically connected by the straight hollowed-out structure.

[0016] Preferably, the first square metal resonant ring structure includes a first metal microstrip, a second metal microstrip, a third metal microstrip, a fourth metal microstrip, and a fifth metal microstrip; the first metal microstrip is vertically arranged.

[0017] The second and fourth metal microstrips are respectively vertically connected to the upper and lower ends of the first metal microstrip;

[0018] The third metal microstrip is vertically connected downwards to the second metal microstrip; the fifth metal microstrip is vertically connected upwards to the fourth metal microstrip; a diode is installed between the third metal microstrip and the fifth metal microstrip.

[0019] Preferably, the first square metal resonant ring structure includes a sixth metal microstrip, a seventh metal microstrip, an eighth metal microstrip, a ninth metal microstrip, and a tenth metal microstrip; the sixth metal microstrip is vertically arranged.

[0020] The seventh and ninth metal microstrips are respectively vertically connected to the upper and lower ends of the sixth metal microstrip;

[0021] The eighth metal microstrip is vertically connected downwards to the seventh metal microstrip; the tenth metal microstrip is vertically connected upwards to the ninth metal microstrip; a diode and a capacitor are connected in parallel between the eighth metal microstrip and the tenth metal microstrip.

[0022] Preferably, the metasurface unit is square.

[0023] As can be seen from the above technical solution, compared with the prior art, this invention discloses an integrated energy-selective metasurface for electromagnetic wave absorption and protection. Through precise control of the pattern size design, it achieves energy selectivity in both the L-band and C-band, allowing low-power signals to pass through while reflecting or blocking high-power electromagnetic energy. Furthermore, it achieves a broadband absorption effect with an absorption rate exceeding 95% in the X-band, integrating multi-band energy-selective protection with broadband high-efficiency absorption. In experimental tests, within the 1.92GHz-2.05GHz and 4.40GHz-4.46GHz operating frequency bands, this invention demonstrates excellent protection performance, exceeding 20dB, effectively restraining high-energy electromagnetic wave attacks and preventing damage to electromagnetic equipment. Simultaneously, it achieves an absorption rate exceeding 90% in the X-band, effectively reducing the RCS (radio frequency cross-section). Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 A perspective view of the metasurface unit structure provided by the present invention;

[0026] Figure 2 Schematic diagrams of the first and second metal circuit structures provided for the present invention;

[0027] Figure 3 A schematic diagram of the third metal circuit structure provided by the present invention;

[0028] Figure 4 The simulation results of low-power incident radiation from the integrated energy-selective metasurface for microwave absorption and protection provided by this invention are shown in the figure.

[0029] Figure 5 The simulation results of high-power incident radiation from the integrated energy-selective metasurface for microwave absorbing and protection provided by this invention are shown in the figure. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention discloses an integrated energy-selective metasurface for microwave absorption and protection. By sequentially arranging a metal circuit structure, a first substrate dielectric substrate, and a second substrate dielectric substrate to form an electromagnetic protection structure and an electromagnetic protection array, it can adaptively cope with low-power signals in the C-band and strong electromagnetic energy across the entire band. It achieves the functions of low-power signal transmission and strong electromagnetic energy protection, and can also achieve good microwave absorption in the X-band. This increases the protection methods of the energy-selective surface, improves its protection performance, and expands its application scenarios.

[0032] This invention discloses an integrated energy-selective metasurface for microwave absorption and protection, comprising multiple periodically arranged metasurface units. This embodiment is... Each metasurface unit.

[0033] refer to Figure 1The metasurface unit includes a first substrate dielectric substrate and a second substrate dielectric substrate arranged in parallel at certain intervals; a first metal circuit structure is printed on the upper surface of the first substrate dielectric substrate, and a second metal circuit structure is printed on the lower surface; a third metal circuit structure is printed on the upper surface of the second substrate dielectric substrate.

[0034] In this embodiment, each metasurface unit is a square structure with a side length p satisfying: 8mm≤p≤12mm; the thickness h1 of the first substrate dielectric substrate satisfies: 3mm≤h1≤5mm; and the thickness h2 of the second substrate dielectric substrate satisfies: 0.5mm≤h2≤2mm.

[0035] The first substrate is an F4B265TSM dielectric substrate with a dielectric constant of 2.65 and a loss tangent of 0.001; the second substrate is a Rogers RT 5880 dielectric substrate with a dielectric constant of 2.2 and a loss tangent of 0.0009.

[0036] The first, second, and third metal circuit structures are coaxial with the first substrate dielectric base. The first and second metal circuit structures are centrally symmetrical ring structures. The first metal circuit structure includes multiple right-angled metal zigzag structures connected by resistors, and the second metal circuit structure includes a metal plate with multiple hollowed-out zigzag structures. The third metal circuit structure includes a first square metal resonant ring structure and a second square metal resonant ring structure. Both the first and second square metal resonant ring structures are C-shaped structures with openings formed by multiple metal microstrips. The first square metal resonant ring structure forms a closed loop by bridging the two ends of the opening with a diode, and the second square metal resonant ring structure forms a closed loop by connecting a diode and a capacitor in parallel across the two ends of the opening.

[0037] In this embodiment, the first metal circuit structure is printed on a dielectric substrate using PCB (Printed Circuit Board) technology. (Reference) Figure 2 The right-angled metal zigzag structure in the first metal circuit structure includes two zigzag units. Each zigzag unit includes five straight metal strips that are connected vertically in sequence. The two zigzag units are connected end to end in a symmetrical structure.

[0038] Specifically, the five straight metal strips are the first straight metal strip, the second straight metal strip, the third straight metal strip, the fourth straight metal strip, and the fifth straight metal strip.

[0039] In the first metal circuit structure, the first metal circuit structure is made of copper material with a thickness of 0.017mm or 0.035mm; the width w1 of the metal strip satisfies 0.1mm≤w1≤0.5mm; the inner edge length l1 of the first straight metal strip satisfies 1mm≤l1≤1.5mm; the inner edge length l2 of the second straight metal strip satisfies 0.4mm≤l2≤0.7mm; the inner edge length l3 of the third straight metal strip satisfies 0.4mm≤l3≤0.7mm; the inner edge length l4 of the fourth straight metal strip satisfies 0.5mm≤l4≤8mm; the inner edge length l5 of the fifth straight metal strip satisfies 0.7mm≤l5≤1mm; the vertical distance between the center of the first metal circuit structure and the inner edge of the first straight metal strip is 1mm≤d1≤1.8mm.

[0040] In the first metal circuit structure, a first gap is provided between adjacent right-angled metal zigzag structures for placing resistors, and the length of the first gap ga satisfies 0.4mm≤ga≤0.6mm.

[0041] According to one embodiment of the present invention, in the first metal circuit structure, the width w1 of all metal strips is 0.4032 mm, the inner edge length l1 of the first straight metal strip is 1.19 mm, the inner edge length l2 of the second straight metal strip is 0.576 mm, the inner edge length l3 of the third straight metal strip is 0.5568 mm, the inner edge length l4 of the fourth straight metal strip is 0.6144 mm, the inner edge length l5 of the fifth straight metal strip is 0.7872 mm, the first gap length ga is 0.5 mm, the distance d1 from the center of the structure to the inner edge of the first straight metal strip is 1.5936 mm, and the resistance value of the welding resistor is R1, which is 100 Ω in this embodiment.

[0042] In this embodiment, the second metal circuit structure is printed on a dielectric substrate using an etching process. The second metal circuit structure includes multiple cutout units, each of which is a symmetrical structure, including a first right-angled cutout structure, two second right-angled cutout structures, and two straight-line cutout structures. The two second right-angled cutout structures are respectively disposed at both ends of the first right-angled cutout structure, and the other end of each second right-angled cutout structure is connected to a straight-line cutout structure. The first right-angled cutout structure is a rectangular groove shape with an open top; the second right-angled cutout structure is an upward-facing right-angled zigzag shape; and the straight-line cutout structure is a straight line shape. The cutout units are vertically connected through the straight-line cutout structures.

[0043] Similarly, the second metal circuit structure is made of copper material with a thickness of 0.017mm or 0.035mm. In the second metal circuit structure, the width w2 of the hollow structure satisfies 0.1mm≤w2≤0.5mm; the inner edge length l6 of the straight hollow structure satisfies 2mm≤l6≤4mm; the inner edge length l7 of the short side of the first right-angle hollow structure satisfies 0.4mm≤l7≤0.7mm; the inner edge length l8 of the long side of the first right-angle hollow structure satisfies 1.1mm≤l8≤1.6mm; the inner edge length l9 of the short side of the second right-angle hollow structure satisfies 0.5mm≤l9≤0.8mm; and the inner edge length l10 of the long side of the second right-angle hollow structure satisfies 1.5mm≤l10≤2mm.

[0044] According to one embodiment of the present invention, the width w2 of all the hollow structures in the second metal circuit structure is 0.3885 mm, the inner edge length l6 of the first straight hollow structure is 3.7 mm, the inner edge length l7 of the short side of the first right-angle hollow structure is 0.555 mm, the inner edge length l8 of the long side of the first right-angle hollow structure is 1.4615 mm, the inner edge length l9 of the short side of the second right-angle hollow structure is 0.74 mm, and the inner edge length l10 of the long side of the second right-angle hollow structure is 1.7205 mm.

[0045] The third metal circuit structure is made of copper with a thickness of 0.017 mm or 0.035 mm.

[0046] like Figure 3 As shown, the first square metal resonant ring structure includes a first metal microstrip, a second metal microstrip, a third metal microstrip, a fourth metal microstrip, and a fifth metal microstrip; the first metal microstrip is vertically arranged; the second metal microstrip and the fourth metal microstrip are respectively vertically connected to the upper and lower ends of the first metal microstrip; the third metal microstrip is vertically connected downwards to the second metal microstrip; the fifth metal microstrip is vertically connected upwards to the fourth metal microstrip; a diode is installed between the third metal microstrip and the fifth metal microstrip.

[0047] Among them, the length l11 of the first metal microstrip satisfies l11=p, and the width w4 satisfies 0.1mm≤w4≤0.4mm; the length l12 of the second metal microstrip satisfies 0.5mm≤l12≤0.8mm, and the width w5 satisfies 0.1mm≤w5≤0.4mm; the length l13 of the third metal microstrip satisfies l11-l13 2≥0.4mm, width w6 satisfies 3mm≤w6≤5mm; opening gap length gb satisfies gb=l11-l13 2; The fourth metal microstrip has the same dimensions as the third metal microstrip; The fifth metal microstrip has the same dimensions as the second metal microstrip.

[0048] The second square metal resonant ring structure includes a sixth, seventh, eighth, ninth, and tenth metal microstrip; the sixth metal microstrip is vertically arranged; the seventh and ninth metal microstrips are vertically connected to the upper and lower ends of the sixth metal microstrip, respectively; the eighth and seventh metal microstrips are vertically connected downwards; the tenth and ninth metal microstrips are vertically connected upwards; there are diodes and capacitors connected in parallel between the eighth and tenth metal microstrips.

[0049] Specifically, in the second square metal resonant ring: the length l14 of the sixth metal microstrip satisfies l14=p, and the width w7 satisfies 0.1mm≤w7≤0.4mm; the length l15 of the seventh metal microstrip satisfies 0.5mm≤l15≤0.8mm, and the width w8 satisfies 0.1mm≤w8≤0.4mm; the length l16 of the eighth metal microstrip satisfies l14-l16 2≥0.4mm, width w9 satisfies 3mm≤w9≤5mm; opening gap length gc satisfies gc=l14-l16 2; The ninth metal microstrip has the same dimensions as the eighth metal microstrip; The tenth metal microstrip has the same dimensions as the seventh metal microstrip.

[0050] According to one embodiment of the present invention, the first metal microstrip of the first square metal resonant ring structure has a length l11 of 11.06 mm and a width w4 of 0.2 mm, a second metal microstrip has a length l12 of 0.65 mm and a width w5 of 0.2 mm, a third metal microstrip has a length l13 of 5.33 mm and a width w6 of 3.6 mm; the sixth metal microstrip of the second square metal resonant ring has a length l14 of 11.06 mm and a width w7 of 0.2 mm, a seventh metal microstrip has a length l15 of 0.55 mm and a width w8 of 0.2 mm, and an eighth metal microstrip has a length l16 of 5.33 mm and a width w9 of 4.2 mm. All substrates have a surface metal structure thickness of 0.035 mm. The diode model is SMP1330-040LF. The resistor R1 has a resistance of 100 Ω, and the capacitor C1 has a capacitance of 0.75 pF. The first substrate has a dielectric substrate width p of 11.06 mm, uses F4B265TSM material, and has a thickness of 4.3 mm. The second substrate has a dielectric substrate width p of 11.06 mm, uses Rogers RT 5880 material, and has a thickness of 1 mm.

[0051] After the energy-selective metasurface was prepared, the N×M array elements in the energy-selective surface were used to perform electromagnetic tests on the incident low-power signal and high-energy electromagnetic wave, respectively, and the expected S11 and S21 curves were obtained.

[0052] Specifically, when a low-power signal passes through an energy selective surface array composed of N×M array elements, its incident power is insufficient to excite the diodes on the energy selective surface array. At this time, the energy selective surface is in an unexcited state, and low-power signals of a specific frequency band can pass through the energy selective surface array with low loss. When a high-energy electromagnetic wave passes through an energy selective surface array composed of N×M array elements, its incident power can excite the diodes on the energy selective surface array. At this time, the energy selective surface is in an excited state, and the high-energy electromagnetic wave will be intercepted when passing through the energy selective surface array. The high-energy electromagnetic wave of the X-band will be absorbed by this energy selective surface array. After processing by the signal transmitter and receiver, the S11 and S21 curves of the energy selective surface array under different incident conditions can be obtained.

[0053] Further, refer to Figure 4 and Figure 5 When low-power signals are incident, the energy-selective surface array exhibits a low insertion loss transmission band around 4.5 GHz, and its absorption rate in the X-band is greater than 90%. When high-energy electromagnetic waves are incident, the energy-selective surface array demonstrates a protection effectiveness greater than 25 dB in the 1-12 GHz range, and its absorption rate in the X-band is greater than 90%. Figure 4 and Figure 5 It can be seen that the difference in the transmission curve between the transparent state and the protected state is at least 20dB, which can effectively control the strength of the transmitted signal and has a good absorption effect in the X-band.

[0054] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0055] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An integrated energy-selective metasurface for microwave absorption and protection, characterized in that, It includes multiple periodically arranged metasurface units; The metasurface unit includes a first substrate dielectric substrate and a second substrate dielectric substrate arranged in parallel at certain intervals. The upper surface of the first substrate dielectric substrate is printed with a first metal circuit structure, and the lower surface is printed with a second metal circuit structure; the upper surface of the second substrate dielectric substrate is printed with a third metal circuit structure. The first metal circuit structure, the second metal circuit structure, and the third metal circuit structure are coaxial with the first substrate dielectric base; wherein, the first metal circuit structure and the second metal circuit structure are centrally symmetrical ring structures, the first metal circuit structure includes multiple right-angled metal zigzag structures connected by resistors, and the second metal circuit structure includes a metal plate with multiple hollowed-out zigzag structures; the third metal circuit structure includes a first square metal resonant ring structure and a second square metal resonant ring structure, both of which are C-shaped structures with openings formed by multiple metal microstrips, wherein the first square metal resonant ring structure forms a closed loop by a diode connected across the two ends of the opening, and the second square metal resonant ring structure forms a closed loop by a diode and a capacitor connected in parallel across the two ends of the opening.

2. The integrated energy-selective metasurface for microwave absorption and protection according to claim 1, characterized in that, The right-angled metal zigzag structure includes two zigzag units, each of which includes five straight metal strips connected vertically in sequence, and the two zigzag units are connected end to end in a symmetrical structure.

3. The integrated energy-selective metasurface for microwave absorption and protection according to claim 1, characterized in that, The second metal circuit structure includes multiple hollow units, each of which is a symmetrical structure, including a first right-angle hollow structure, two second right-angle hollow structures and two straight-line hollow structures; Two second right-angled hollow structures are respectively disposed at both ends of the first right-angled hollow structure, and the other end of each second right-angled hollow structure is connected to one of the straight hollow structures; The first right-angled hollow structure is a rectangular groove shape with an open top; the second right-angled hollow structure is an upward-facing right-angled broken line shape; the straight-line hollow structure is a straight line shape. The hollowed-out units are vertically connected by the straight hollowed-out structure.

4. The integrated energy-selective metasurface for microwave absorption and protection according to claim 1, characterized in that, The first square metal resonant ring structure includes a first metal microstrip, a second metal microstrip, a third metal microstrip, a fourth metal microstrip, and a fifth metal microstrip; the first metal microstrip is vertically arranged. The second and fourth metal microstrips are respectively vertically connected to the upper and lower ends of the first metal microstrip; The third metal microstrip is vertically connected downwards to the second metal microstrip; the fifth metal microstrip is vertically connected upwards to the fourth metal microstrip; a diode is installed between the third metal microstrip and the fifth metal microstrip.

5. The integrated energy-selective metasurface for microwave absorption and protection according to claim 1, characterized in that, The first square metal resonant ring structure includes a sixth metal microstrip, a seventh metal microstrip, an eighth metal microstrip, a ninth metal microstrip, and a tenth metal microstrip; the sixth metal microstrip is vertically arranged. The seventh and ninth metal microstrips are respectively vertically connected to the upper and lower ends of the sixth metal microstrip; The eighth metal microstrip is vertically connected downwards to the seventh metal microstrip; the tenth metal microstrip is vertically connected upwards to the ninth metal microstrip; a diode and a capacitor are connected in parallel between the eighth metal microstrip and the tenth metal microstrip.

6. The integrated energy-selective metasurface for microwave absorption and protection according to claim 1, characterized in that, The metasurface unit is square.

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