Low-pass high-absorption energy selective surface based on meander structure

Abstract

The application discloses a low-pass high-absorption energy selective surface based on a meander structure, comprising a plurality of periodically distributed units, each unit sequentially comprising a frequency selective layer, a dielectric layer and an energy selective layer from top to bottom, the frequency selective layer comprising a first dielectric substrate and a plurality of metal meander structures and resistors on the upper and lower surfaces of the first dielectric substrate, the energy selective layer comprising a second dielectric substrate and a plurality of metal block structures and diodes on the upper surface of the second dielectric substrate, and the frequency selective layer and the energy selective layer being separated by the dielectric layer. The energy selective surface and the frequency selective surface of the application are impedance matched through the dielectric layer, when low-power electromagnetic waves are incident, a low-insertion-loss low-pass band is realized, and a wide absorption band is formed outside the band; when high-power electromagnetic waves are incident, a reflection band with high shielding effectiveness is realized in the working frequency band, and a wide absorption band is formed outside the band. The overall design structure principle of the application is simple and clear, and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electromagnetic protection, and relates to a low-pass high-absorption energy selective surface based on a meander structure. BACKGROUND

[0002] In a complex electromagnetic environment, an energy selective surface (ESS) is an important and practical periodic electromagnetic surface for coping with a high-power environment. Components of the energy selective surface mainly include a frequency selective surface and a diode, and impedance transformation of the diode at different powers can generate a working state and a protection state.

[0003] There are various types in the frequency selective surface in the working state, such as a band-pass, a low-pass, a wave absorption, and a polarization conversion, among which the wave absorption has important significance for electromagnetic protection and stealth, and the addition of a stealth wave band has a great effect on electromagnetic equipment under low-power electromagnetic wave incidence. If shielding and stealth can be achieved under high-power electromagnetic wave incidence, the research direction of the energy selective surface can be greatly expanded and the needs in actual applications can be met. The wave absorption is usually realized by using a wave absorption material and a resonant structure, and the resonant structure can obtain a wave absorption frequency band of any wave band by designing different structures and resistances. Compared with the wave absorption material, the resonant structure has a clearer design principle and a lower processing cost, and is thus more suitable for actual applications.

[0004] However, most of the energy selective surfaces reported at present are aimed at working frequency bands and protection frequency bands, and few studies are made on the stealth frequency band in the frequency selective surface. SUMMARY

[0005] The application aims at the deficiencies of the prior art, and provides a low-pass high-absorption energy selective surface based on a meander structure. The energy selective surface and the frequency selective surface are cascaded and impedance matched with a dielectric layer, a low-frequency passband with low insertion loss is realized when low-power electromagnetic waves are incident, a wide wave absorption frequency band is formed outside the passband, a low-frequency reflection band with high shielding effectiveness is realized when high-power electromagnetic waves are incident, and a wide wave absorption frequency band is formed outside the reflection band.

[0006] The low-pass high-absorption energy selective surface based on the meander structure is a vertical arrangement structure, and the structure is a unit arranged periodically (arranged seamlessly in x and y two periodic directions). Each unit includes, from top to bottom, a frequency selective layer, a dielectric layer, and an energy selective layer connected in sequence.

[0007] The frequency selective layer includes a first dielectric substrate.

[0008] The upper surface of the first dielectric substrate is provided with a first metal meander structure, a second metal meander structure, a third metal meander structure, a fourth metal meander structure, a first resistor, a second resistor, a third resistor, and a fourth resistor; the first metal meander structure, the second metal meander structure, the third metal meander structure, and the fourth metal meander structure have the same structure and each include two metal edges and three metal lines, the two metal edges are arranged perpendicularly, and the three metal lines extend perpendicularly to one of the metal edges to the center of the first dielectric substrate; one metal edge of the first metal meander structure is connected to one metal edge of the second metal meander structure through the first resistor, the other metal edge of the second metal meander structure is connected to one metal edge of the third metal meander structure through the second resistor, the other metal edge of the third metal meander structure is connected to one metal edge of the fourth metal meander structure through the third resistor, and the other metal edge of the fourth metal meander structure is connected to the other metal edge of the first metal meander structure through the fourth resistor;

[0009] The lower surface of the first dielectric substrate is provided with a fifth metal meander structure, a sixth metal meander structure, a seventh metal meander structure, an eighth metal meander structure, a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor; the fifth metal meander structure, the sixth metal meander structure, the seventh metal meander structure, and the eighth metal meander structure have the same structure and each has a continuous "arch" shape, one end of the fifth metal meander structure is connected to one end of the sixth metal meander structure through the fifth resistor, the other end of the sixth metal meander structure is connected to one end of the seventh metal meander structure through the sixth resistor, the other end of the seventh metal meander structure is connected to one end of the eighth metal meander structure through the seventh resistor, and the other end of the eighth metal meander structure is connected to the other end of the fifth metal meander structure through the eighth resistor; the first dielectric substrate has the same size as the unit and has a thickness t d1 0.005λ L 0.008λ L , λ a is the wavelength corresponding to the starting frequency of the structure.

[0010] The selectable layer includes a second dielectric substrate and a first metal block structure, a second metal block structure, a third metal block structure, a fourth metal block structure, a fifth metal block structure, a sixth metal block structure, a seventh metal block structure, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, a seventh diode, and an eighth diode on the upper surface thereof. One end of the first metal block structure is connected to one end of the second metal block structure and one end of the third metal block structure through the first diode and the second diode, respectively, and the other end of the second metal block structure and the other end of the third metal block structure are connected to one end of the seventh metal block structure through the third diode and the fourth diode, respectively;

[0011] One end of the fourth metal block structure is connected to one end of the fifth metal block structure and one end of the sixth metal block structure through the fifth diode and the sixth diode, respectively, and the other end of the second metal block structure and the other end of the third metal block structure are connected to one end of the seventh metal block structure through the third diode and the fourth diode, respectively. The upper left corner of the seventh metal block structure is provided with a rectangular notch. The second dielectric substrate has the same size as the unit and a thickness t d2 0.005λ a 0.008λ a , λ a is the wavelength corresponding to the starting frequency of the structure.

[0012] The dielectric layer has the same size as the unit and a thickness t a 0.01λ a 0.03λ a , λ a is the wavelength corresponding to the starting frequency of the structure. The dielectric layer plays a role of impedance matching for the frequency-selective layer and the selectable layer.

[0013] As a preferred embodiment, the width of the metal edges and metal lines in the first metal meander structure, the second metal meander structure, the third metal meander structure, and the fourth metal meander structure is smaller than the width of the metal edges and metal lines in the fifth metal meander structure, the sixth metal meander structure, the seventh metal meander structure, and the eighth metal meander structure. This is because the metal meander structures on the upper surface and the lower surface produce two resonance points, the metal meander structure with a smaller width produces a larger inductance, the metal meander structure with a larger width produces a smaller inductance, and the metal lines in the periodic unit produce a coupling capacitance, and the inductance and the capacitance produce resonance. Therefore, in order to have different resonance points, the widths of the metal meander structures on the upper surface and the lower surface are different.

[0014] As a preferred embodiment, the first to fourth metal meander structures are arranged at 45° with respect to the center of the frequency-selective layer.

[0015] As a preference, the fifth to eighth metal meander structures are arranged 45° about the center of the frequency selective layer.

[0016] As a preference, the first to fourth resistors are arranged 45° about the center of the frequency selective layer.

[0017] As a preference, the fifth to eighth resistors are arranged 45° about the center of the frequency selective layer.

[0018] As a preference, the first to fourth diodes are arranged diagonally symmetrically about the frequency selective layer, the fifth to eighth diodes are arranged diagonally symmetrically about the frequency selective layer.

[0019] As a preference, the first to fourth metal block structures are arranged diagonally symmetrically about the frequency selective layer, the fifth to eighth metal block structures are arranged diagonally symmetrically about the frequency selective layer.

[0020] As a preference, the medium of the medium layer is air.

[0021] As a preference, the medium of the first and second medium substrates is Rogers RT5008 with a dielectric constant of 2.2.

[0022] As a preference, the first to fourth resistors are all 400Ω resistors.

[0023] As a preference, the fifth to eighth resistors are all 600Ω resistors.

[0024] As a preference, the first to eighth diodes are all SMP1330 from SKYWORKS.

[0025] As a preference, the thickness ratio of the first and second medium substrates is 1:1.

[0026] As a preference, the thickness ratio of the first (or second) medium substrate and the medium layer is 1:20.

[0027] As preferred, the frequency selective layer and the energy selective layer are impedance matched by the dielectric layer, realizing a low insertion loss low frequency passband and a wide high frequency absorption band out of the band under low power electromagnetic wave incidence, and realizing a low frequency reflection band with high shielding effectiveness and a wide high frequency absorption band out of the band under high power electromagnetic wave incidence.

[0028] Specific working principle:

[0029] When high and low electromagnetic waves are incident, the metal meander structure on the upper surface and the lower surface in the frequency selective layer is equivalent to a large inductor and a small inductor respectively, and a coupling capacitor is generated between the metal meander structures in the periodic unit, that is, a large capacitor and a small capacitor are generated on the upper surface and the lower surface respectively, and then the whole frequency selective layer in series with the resistor can be equivalent to a two-RLC parallel structure; when a metal back plate is added to the frequency selective layer, it presents the performance of an absorber, that is, a low frequency reflection and high frequency absorption filtering characteristic. In order to realize the low-pass high-absorption type energy selective surface, the energy selective layer is replaced by a metal back plate and then matched by a dielectric layer.

[0030] When low power electromagnetic waves are incident, the eight diodes in the energy selective layer are in an off state, and the diodes at this time can be equivalent to a cut-off capacitor. Then the energy selective layer can be equivalent to an LC series structure, presenting a low frequency transmission and high frequency reflection filtering characteristic; then the frequency selective layer is impedance matched by the dielectric layer, and a wideband absorber is formed in high frequency by using the high frequency reflection characteristic of the energy selective layer, and the frequency selective layer and the energy selective layer both present a low frequency transmission characteristic in low frequency, that is, a transmission band can be obtained in low frequency, and a wideband absorption can be obtained in high frequency. The eight diodes are provided in the energy selective layer, because as preferred, the diodes cannot form a complete loop in a single quantity, which will cause the structure to not present the required state.

[0031] When high power electromagnetic waves are incident, the eight diodes in the energy selective layer are in an on state, and the diodes at this time can be equivalent to a conducting resistance. Then the energy selective layer can be equivalent to an inductive structure (the conducting resistance is extremely small and can be ignored), and the whole frequency band presents a reflection filtering characteristic, and then the frequency selective layer is impedance matched by the dielectric layer, and a high shielding effectiveness reflection band is obtained in low frequency, and a wide absorption band is obtained in high frequency by using the reflection characteristic of the energy selective layer.

[0032] Compared with the prior art, the low-pass high-absorption type energy selective surface based on the meander structure has the following advantages:

[0033] (1) The application is designed based on three-layer structure to obtain low insertion loss low-frequency passband and wide-frequency absorbing band outside the band under low-power electromagnetic wave incidence, and to obtain a high shielding effectiveness reflection band and a wide-frequency absorbing band outside the band under high-power electromagnetic wave incidence. The upper surface of the frequency selection layer adopts an elongated plurality of metal meander lines, and the lower surface adopts a long plurality of metal meander lines, thereby providing more inductance and effectively reducing the size of the unit size. Through impedance matching between the frequency selection layer and the energy selection layer and the dielectric layer, the working absorbing bandwidth and protection performance are improved.

[0034] (2) The low-pass high-absorption type energy selection surface based on the meander structure provided by the application combines the energy selection surface and the wave absorber, efficiently utilizes the performance of both, realizes good impedance matching effect, provides clear principle, provides ideas for the blank of such work, and can be applied to stealth technology, radar technology, protection technology and electromagnetic interference suppression and other protection fields. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a three-dimensional structure unit schematic diagram of a low-pass high-absorption type energy selection surface based on a meander structure of the application;

[0036] Figure 2 is a top view of the upper surface of the frequency selection layer of a low-pass high-absorption type energy selection surface based on a meander structure of the application;

[0037] Figure 3 is a top view of the lower surface of the frequency selection layer of a low-pass high-absorption type energy selection surface based on a meander structure of the application;

[0038] Figure 4 is a top view of the energy selection layer of a low-pass high-absorption type energy selection surface based on a meander structure of the application;

[0039] Figure 5 is a front view of a low-pass high-absorption type energy selection surface based on a meander structure of the application;

[0040] Figure 6 is a schematic diagram of the equivalent circuit of a low-pass high-absorption type energy selection surface based on a meander structure of the application;

[0041] Figure 7 is a scattering characteristic curve diagram of a low-pass high-absorption type energy selection surface based on a meander structure of the application under low-power incident electromagnetic wave irradiation;

[0042] Figure 8 is a scattering characteristic curve diagram of a low-pass high-absorption type energy selection surface based on a meander structure of the application under high-power incident electromagnetic wave irradiation;

[0043] Figure 9This is a comparison diagram of the scattering rates of a low-pass high-absorption energy selective surface based on a zigzag structure of the present invention when irradiated with a low-power incident electromagnetic wave;

[0044] Figure 10 This is a comparison diagram of the scattering rates of a low-pass high-absorption energy selective surface based on a zigzag structure of the present invention when irradiated with a high-power incident electromagnetic wave;

[0045] Markings in the figure: frequency selective layer 1, dielectric layer 2, energy selective layer 3, first dielectric substrate 1a, first metal zigzag structure 1b, second metal zigzag structure 1c, third metal zigzag structure 1d, fourth metal zigzag structure 1e, first resistor 1f, second resistor 1g, third resistor 1h, fourth resistor 1i, second dielectric substrate 2a, fifth metal zigzag structure 2b, sixth metal zigzag structure 2c, seventh metal zigzag structure 2d, eighth metal zigzag structure 2e, fifth resistor 2f, sixth resistor 2g, seventh resistor 2h, eighth resistor 2i, first metal block structure 3a, second metal block structure 3b, third metal block structure 3c, fourth metal block structure 3d, fifth metal block structure 3e, sixth metal block structure 3f, seventh metal block structure 3g, first diode 4a, second diode 4b, third diode 4c, fourth diode 4d, fifth diode 4e, sixth diode 4f, seventh diode 4g, eighth diode 4h. DETAILED DESCRIPTION

[0046] The present invention will be further analyzed below with reference to specific embodiments.

[0047] like Figure 1 As shown, a low-pass, high-absorption energy selective surface based on a zigzag structure has a vertically arranged structure, including periodically distributed and seamlessly covered units, each of which includes a frequency selective layer 1, a dielectric layer 2, and an energy selective layer 3 from top to bottom.

[0048] like Figure 2 As shown, the upper surface of the frequency-selective layer 1 includes a first dielectric substrate 1a and, located thereon, a first metal zigzag structure 1b, a second metal zigzag structure 1c, a third metal zigzag structure 1d, a fourth metal zigzag structure 1e, a first resistor 1f, a second resistor 1g, a third resistor 1h, and a fourth resistor 1i. The first to fourth metal zigzag structures (1b, 1c, 1d, 1e) are composed of three thin zigzag metal wires. The first to fourth metal zigzag structures (1b, 1c, 1d, 1e) are connected by the first to fourth resistors (1f, 1g, 1h, 1i). The size of the first dielectric substrate 1a is the same as the unit size. The first to fourth resistors (1f, 1g, 1h, 1i) have a resistance value of 400Ω.

[0049] like Figure 3As shown in the figure, the lower surface of the frequency selective layer 1 includes a first dielectric substrate 1a and a fifth metal meander structure 2b, a sixth metal meander structure 2c, a seventh metal meander structure 2d, an eighth metal meander structure 2e, a fifth resistor 2f, a sixth resistor 2g, a seventh resistor 2h, and an eighth resistor 2i on the lower surface thereof; the fifth to eighth metal meander structures (2b, 2c, 2d, 2e) are composed of two thick meander metal wires; the fifth to eighth metal meander structures (2b, 2c, 2d, 2e) are connected by the fifth to eighth resistors (2f, 2g, 2h, 2i); the first dielectric substrate 1a has the same size as the unit; the fifth to eighth resistors (2f, 2g, 2h, 2i) have a resistance of 600Ω.

[0050] As shown in the figure, Figure 4 As shown in the figure, the energy selective layer 3 includes a second dielectric substrate 2a and a first metal block structure 3a, a second metal block structure 3b, a third metal block structure 3c, a fourth metal block structure 3d, a fifth metal block structure 3e, a sixth metal block structure 3f, a seventh metal block structure 3g, a first diode 4a, a second diode 4b, a third diode 4c, a fourth diode 4d, a fifth diode 4e, a sixth diode 4f, a seventh diode 4g, and an eighth diode 4h on the upper surface thereof. The lower side edges of the first metal block structure 3a are connected to the second metal block structure 3b and the third metal block structure 3c through the first diode 4a and the second diode 4b, respectively; the second metal block structure 3b and the third metal block structure 3c are connected to the seventh metal block structure 3g through the third diode 4c and the fourth diode 4d, respectively; the right side edges of the fourth metal block structure 3d are connected to the fifth metal block structure 3e and the sixth metal block structure 3f through the fifth diode 4e and the sixth diode 4f, respectively; the fifth metal block structure 3e and the sixth metal block structure 3f are connected to the seventh metal block structure 3g through the seventh diode 4g and the eighth diode 4h, respectively; a rectangular notch is arranged at the upper left corner of the seventh metal block structure 3g; the second dielectric substrate 2a has the same size as the unit and is made of Rogers RT5008 with a dielectric constant of 2.2; and the first to eighth diodes (4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h) are all SMP1330 of SKYWORKS.

[0051] As shown in the figure, Figure 5 As shown in the figure, the medium of the medium layer 2 is air, and the size is the same as that of the unit; the medium layer 2 is located between the frequency selective layer 1 and the energy selective layer 3.

[0052] As shown in the figure, Figure 6 As shown in the figure, the low-pass high-absorption type energy selective surface based on the meander structure of the present application can be equivalent to a specific circuit model.

[0053] The first metal meander structure 1b, the second metal meander structure 1c, the third metal meander structure 1d, and the fourth metal meander structure 1e in the upper surface of the frequency selective layer 1 can be equivalent to an inductor L1; the first resistor 1f, the second resistor 1g, the third resistor 1h, and the fourth resistor 1i can be equivalent to a resistor R1; since the structure is a periodic unit, the first to fourth metal meander structures (1b, 1c, 1d, 1e) between units will have an equivalent coupling capacitor C1; the fifth metal meander structure 2b, the sixth metal meander structure 2c, the seventh metal meander structure 2d, and the eighth metal meander structure 2e in the lower surface of the frequency selective layer 1 can be equivalent to an inductor L2; the fifth resistor 2f, the sixth resistor 2g, the seventh resistor 2h, and the eighth resistor 2i can be equivalent to a resistor R2; since the structure is a periodic unit, the fifth to eighth metal meander structures (2b, 2c, 2d, 2e) between units will have an equivalent coupling capacitor C2; the first dielectric substrate 1a in the frequency selective layer 1 can be equivalent to a lossy transmission line with a characteristic impedance of Z d1 , where β d1 and t d1 are the propagation constant and thickness of the first dielectric substrate 1a;

[0054] The dielectric layer 2 can be equivalent to a lossless transmission line with a characteristic impedance of Z a , where β a and t a are the propagation constant and thickness of the dielectric layer 2;

[0055] The first metal block structure 3a, the second metal block structure 3b, the third metal block structure 3c, the fourth metal block structure 3d, the fifth metal block structure 3e, the sixth metal block structure 3f, and the seventh metal block structure 3g in the energy selective layer 3 can be equivalent to an inductor L3; the first diode 4a and the fifth diode 4e can be equivalent to a diode D3, the second diode 4b and the sixth diode 4f can be equivalent to a diode D1, the third diode 4c and the seventh diode 4g can be equivalent to a diode D4, and the fourth diode 4d and the eighth diode 4h can be equivalent to a diode D2; the second dielectric substrate 2a can be equivalent to a lossy transmission line with a characteristic impedance of Z d2 , where β d2 and t d2 are the propagation constant and thickness of the second dielectric substrate 2a.

[0056] According to the equivalent circuit model, the ABCD transmission matrix of the frequency selective layer 1, the dielectric layer 2, and the energy selective layer 3 can be obtained respectively:

[0057]

[0058] The A1B1C1D1 transmission matrix describes the frequency-selective layer 1, where Z1 is the impedance of the upper surface of the frequency-selective layer 1 (Z1=jwL1+1 / jwC1+R1), and Z2 is the impedance of the lower surface of the frequency-selective layer 1 (Z2=jwL2+1 / jwC2+R2). d1 , β d1 and t d1 are the characteristic impedance, propagation constant and thickness of the first dielectric substrate 1a.

[0059]

[0060] The A2B2C2D2 transmission matrix describes the dielectric layer 2, where β a and t a is the propagation constant and thickness of dielectric layer 2, the characteristic impedance Z of dielectric layer 2 (preferably air) a is 377Ω.

[0061]

[0062] The A3B3C3D3 transmission matrix describes the energy-selective layer 3, where Z3 is the impedance of the surface of the energy-selective layer 3 (Z3=jwL3+Z D ); Z D is the equivalent impedance of the diode; Z d2 , β d2 and t d2 are the characteristic impedance, propagation constant and thickness of the second dielectric substrate 2a.

[0063]

[0064] The ABCD transmission matrix describes a low-pass, high-absorption energy selective surface based on a zigzag structure of the present invention. The formulas for the reflection coefficient and transmission coefficient can be obtained based on the matrix:

[0065]

[0066] Under ideal conditions, Z0 represents air with an impedance of 377Ω. Under low-power electromagnetic waves, the diode acts as a cutoff capacitor; under high-power electromagnetic waves, the diode acts as an on-resistance. The equivalent circuit and impedance changes reveal three distinct states: operating, invisible, and protected.

[0067] like Figure 7 As shown in the figure, under low-power electromagnetic wave incidence, the structure of the present invention has a low-frequency passband from DC to 1.7 GHz with an insertion loss below 3 dB. At the same time, it has a wide absorption band at high frequencies, with an absorption effect exceeding 90% in the 3.9–8.87 GHz range, and a relative bandwidth of 77.8%.

[0068] As Figure 8 shown, it can be seen that in the case of high-power electromagnetic wave incidence, the structure of the application has a shielding band with shielding effectiveness of 25 dB or more within DC-0.89 GHz, and a wide absorption band at high frequency, with an absorption effect of 90% or more in the band of 2.49-8.73 GHz, and a relative bandwidth of 111.2%.

[0069] The specific structural parameters are described as follows:

[0070] Where p is the length and width of the entire unit structure in the x and y axes, and is also the length and width of the frequency selection layer 1, the dielectric layer 2, the energy selection layer 3, the first dielectric substrate 1a, and the second dielectric substrate 2a. w1 and l1 are the width and length of the first to fourth metal meander structures (1b, 1c, 1d, 1e), w2 and w3 are the length and width of the thin meander lines. w4 and l2 are the width and length of the fifth to eighth metal meander structures (2b, 2c, 2d, 2e), w5 and w6 are the length and width of the thick meander lines. r1 and r2 are the lengths of the first to fourth resistors (1f, 1g, 1h, 1i) and the fifth to eighth resistors (2f, 2g, 2h, 2i). l4 and w8 are the length and width of the first metal block structure 3a and the fourth metal block structure 3d, l3 and w7 are the width and length of the second to third / fifth to sixth metal block structures (3b, 3c, 3e, 3f) and the seventh metal block structure 3g. d1 and d2 are the length and width of the first to eighth diodes (4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h). t d1 is the thickness of the first dielectric substrate 1a, t a2 is the thickness of the dielectric layer 2, t d2 is the thickness of the second dielectric substrate 2a.

[0071] Figure 9 is a comparison chart of the scattering rate characteristics of the structure under low-power electromagnetic wave incidence. It can be seen that there is more than 80% transmittance in the frequency band of DC-0.7 GHz, and more than 50% (3 dB) transmittance in the frequency band of DC-1.7 GHz; and there is more than 80% absorption rate in the wide band of high frequency 3.7-9.1 GHz; except for the wave band where the passband exceeds the absorption band, the reflectivity is below 10%, indicating good stealth characteristics outside the band.

[0072] Figure 10The scattering rate characteristic curve contrast chart of the structure under high power electromagnetic wave incidence can be seen. It can be seen that the transmissivity of DC-8GHz band is almost below 5%, which shows that the shielding performance is excellent; the reflectivity of more than 50% exists in the wide band of low frequency DC-1.8GHz, and most of the electromagnetic waves which are not reflected are absorbed by the resistance; the wave absorption rate of more than 80% exists in the wide band of high frequency 2.3-8.8GHz, and the stealth protection effect is very good.

[0073] It can be seen that the results of the present application have a low insertion loss low-frequency passband at low power, and an ultra-wide absorption band at high frequency; at high power, the shielding performance is high and wide at low frequency, and the absorption band is still wide at high frequency.

[0074] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled persons in the art, without departing from the principles of the present application, by changing the material type / property of the frequency selective layer, the energy selective layer and the dielectric layer (diode and resistance), or changing the structure form, size and other several improvements and decorations, these improvements and decorations should also be regarded as the protection scope of the present application.

Claims

1. A low-pass high-absorption energy selective surface based on meandering structure, comprising a plurality of periodically distributed units, characterized in that, Each unit comprises, from top to bottom, a frequency selection layer, a dielectric layer and an energy selection layer connected in sequence; the frequency selection layer, the dielectric layer and the energy selection layer have the same size as the unit; The frequency selection layer comprises a first dielectric substrate; The upper surface of the first dielectric substrate is provided with a first metal meander structure, a second metal meander structure, a third metal meander structure, a fourth metal meander structure, a first resistor, a second resistor, a third resistor and a fourth resistor; the first metal meander structure, the second metal meander structure, the third metal meander structure and the fourth metal meander structure have the same structure and each comprise two metal edges and three metal lines, the two metal edges are arranged perpendicularly, and the three metal lines extend perpendicularly to one of the metal edges to the center of the first dielectric substrate; one metal edge of the first metal meander structure is connected to one metal edge of the second metal meander structure through the first resistor, the other metal edge of the second metal meander structure is connected to one metal edge of the third metal meander structure through the second resistor, the other metal edge of the third metal meander structure is connected to one metal edge of the fourth metal meander structure through the third resistor, and the other metal edge of the fourth metal meander structure is connected to the other metal edge of the first metal meander structure through the fourth resistor; The lower surface of the first dielectric substrate is provided with a fifth metal meander structure, a sixth metal meander structure, a seventh metal meander structure, an eighth metal meander structure, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; the fifth metal meander structure, the sixth metal meander structure, the seventh metal meander structure and the eighth metal meander structure have the same structure and each present a continuous "arch" shape, one end of the fifth metal meander structure is connected to one end of the sixth metal meander structure through the fifth resistor, the other end of the sixth metal meander structure is connected to one end of the seventh metal meander structure through the sixth resistor, the other end of the seventh metal meander structure is connected to one end of the eighth metal meander structure through the seventh resistor, and the other end of the eighth metal meander structure is connected to the other end of the fifth metal meander structure through the eighth resistor; The energy selection layer comprises a second dielectric substrate, a first metal block structure, a second metal block structure, a third metal block structure, a fourth metal block structure, a fifth metal block structure, a sixth metal block structure, a seventh metal block structure, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, a seventh diode and an eighth diode on the upper surface of the second dielectric substrate; in the energy selection layer: One end of the first metal block structure is connected to one end of the second metal block structure and one end of the third metal block structure through the first diode and the second diode respectively, and the other end of the second metal block structure and the other end of the third metal block structure are connected to one end of the seventh metal block structure through the third diode and the fourth diode respectively; One end of the fourth metal block structure is connected to one end of the fifth metal block structure and one end of the sixth metal block structure through the fifth diode and the sixth diode respectively, the other end of the second metal block structure and the other end of the third metal block structure are connected to one end of the seventh metal block structure through the third diode and the fourth diode respectively; one corner of the seventh metal block structure is provided with a rectangular notch.

2. A low-pass high-absorption energy selective surface based on meandering structures according to claim 1, characterized in that, The first metal meander structure, the second metal meander structure, the third metal meander structure and the fourth metal meander structure are arranged at 45° about the center of the frequency selective layer, and the first resistance, the second resistance, the third resistance and the fourth resistance are arranged at 45° about the center of the frequency selective layer; the fifth metal meander structure, the sixth metal meander structure, the seventh metal meander structure and the eighth metal meander structure are arranged at 45° about the center of the frequency selective layer, and the fifth resistance, the sixth resistance, the seventh resistance and the eighth resistance are arranged at 45° about the center of the frequency selective layer.

3. The low-pass high-absorption energy selective surface based on meander structure according to claim 1, characterized in that, The width of the metal edges and metal lines in the first metal meander structure, the second metal meander structure, the third metal meander structure and the fourth metal meander structure is smaller than the width of the metal edges and metal lines in the fifth metal meander structure, the sixth metal meander structure, the seventh metal meander structure and the eighth metal meander structure.

4. The low-pass high-absorption energy selective surface based on meander structure according to claim 1, characterized in that, The first diode and the fifth diode are arranged symmetrically about the diagonal line of the frequency selective layer, the second diode and the sixth diode are arranged symmetrically about the diagonal line of the frequency selective layer, the third diode and the seventh diode are arranged symmetrically about the diagonal line of the frequency selective layer, and the fourth diode and the eighth diode are arranged symmetrically about the diagonal line of the frequency selective layer.

5. The low-pass high-absorption energy selective surface based on meandering structures according to claim 1, characterized in that, The first metal block structure and the fourth metal block structure are arranged symmetrically about the diagonal line of the frequency selective layer, the second metal block structure and the fifth metal block structure are arranged symmetrically about the diagonal line of the frequency selective layer, the third metal block structure and the sixth metal block structure are arranged symmetrically about the diagonal line of the frequency selective layer, and the seventh metal block structure is arranged symmetrically about the diagonal line of the frequency selective layer.

6. A low-pass high-absorption energy selective surface based on meandering structures according to claim 1, characterized in that, The medium in the medium layer is air.

7. The low-pass high-absorption energy-selective surface based on meandering structures according to claim 1, characterized in that, The first resistance, the second resistance, the third resistance and the fourth resistance all adopt resistors with a resistance of 400Ω, and the fifth resistance, the sixth resistance, the seventh resistance and the eighth resistance all adopt resistors with a resistance of 600Ω.

8. The low-pass high-absorption energy selective surface based on meander structure according to claim 1, characterized in that, The thickness ratio of the first medium substrate to the second medium substrate is 1:

1.

9. The low-pass high-absorption energy-selective surface based on meandering structures according to claim 1, characterized in that, The thickness ratio of the second medium substrate to the medium layer is 1:20.

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