Dual-passband window wave absorber device

Abstract

According to the dual-passband window wave absorber device provided by the invention, by optimizing devices, components and a setting mode, the device can give consideration to two separated wave-transparent frequency bands and one wave-absorbing frequency band in a working frequency band. The device is composed of a wave absorbing layer and a wave-transparent layer, an inductor and a capacitor are introduced into the wave absorbing layer to construct a double-layer wave-transparent layer so as to improve the wave-transparent bandwidth and steep cut-off selectivity, a second-order band-pass filter is cascaded on the wave-transparent layer to form a double-wave-transparent window, and the functions of double-frequency-band wave transmission and broadband wave absorption are achieved. The problem that an existing dual-passband window wave absorber is difficult to give consideration to out-of-band broadband wave absorption and in-band broadband wave transmission at the same time is effectively solved, it is further guaranteed that an antenna system has good out-of-band RCS reduction and normal in-band signal transmission, and the stealth performance of a dual-band conformal antenna is improved. By designing and regulating the frequency points and insertion loss of the double wave-transparent windows, the out-of-band wave-transparent rate of the wave-absorbing layer is improved, and the wave-transparent insertion loss requirement of multi-layer cascade is met.

Description

Technical Field

[0001] The invention belongs to the field of stealth technology, and in particular relates to a dual-passband window absorber device. Background Art

[0002] With the advancement of stealth technology, the strong scattering of antenna systems on large platforms has become a major contributor to the overall radar cross section (RCS). Traditional stealth technologies, both in terms of shape and material, have a significant impact on antenna radiation performance, making it difficult to meet current requirements.

[0003] Window absorbers are structural devices that combine wave absorption and wave transmission. They function as antenna covers, effectively suppressing scattering spots while ensuring proper antenna transmission. However, as frequency-using devices evolve toward high integration, dual-band conformal antennas have become the norm. Traditional window absorbers, with only a single transmission frequency, struggle to meet current application requirements. Existing dual-band window absorber designs suffer from narrow absorption and transmission bandwidths, making them unsuitable for demanding applications.

[0004] A search of domestic and foreign literature shows that there is still a blank in China regarding the design of a window absorber with a wide dual-wave transmission band, and the above-mentioned defects or improvement needs of the existing technology need to be addressed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a dual-passband window absorber device for dual-band wave transmission and broadband wave absorption.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: a dual-passband window absorber device, comprising a first absorbing layer, a first dielectric isolation layer, a second wave-transmitting layer, a second dielectric isolation layer and a third wave-transmitting layer arranged in sequence from top to bottom; The first absorbing layer is a single-sided copper-clad laminate with an array of Jerusalem cross patterns periodically arranged in rows and columns. Each Jerusalem cross pattern in the array consists of a central square with a meandering gap and two gaps on each of the four sides of the square starting from the center. A lumped resistor is welded into the gap near the center, while an inductor and capacitor are welded at each end of the gap away from the center. This constitutes the first absorbing layer FSS unit. The second wave-transmitting layer is a single-sided copper-clad laminate with an array of square and circular ring gap patterns periodically arranged in rows and columns. Any square ring and circular ring gap pattern in the array includes a central circular pattern, an outermost square ring pattern, and a filling pattern between the circular and square ring patterns. A circular gap is provided between the circular pattern and the filling pattern, and a square gap is provided between the filling pattern and the square ring pattern. This constitutes the FSS unit of the second wave-transmitting layer. The third wave-transmitting layer is a single-sided copper-clad board with an array of square-ring and circular-ring gap patterns periodically arranged in rows and columns on the copper foil. Any square-ring and circular-ring gap pattern in the array includes a circular pattern in the center, an outermost square-ring pattern, and a filling pattern between the circular and square ring patterns. A circular gap is provided between the circular pattern and the filling pattern, and a square gap is provided between the filling pattern and the square ring pattern. This constitutes the FSS unit of the third wave-transmitting layer.

[0007] According to the above scheme, the serpentine gap divides the inside of the square pattern into an X-shaped pattern, and the hypotenuse of the X-shaped pattern is a serrated wavy line, and the serrations are all right angles.

[0008] According to the above solution, for any gap used for welding an inductor device or a capacitor device, the width of the gap is 0.3 mm to 0.8 mm.

[0009] According to the above scheme, the line width of the Jerusalem cross pattern is 0.2 mm to 1 mm; the width of the gap used for welding the lumped resistor is 0.5 mm.

[0010] According to the above scheme, the radius of the circular pattern is 7mm to 9mm; the line width of the filling pattern is 0.1mm to 16.5mm; and the line width of the square ring pattern is 0.2mm to 1mm.

[0011] According to the above scheme, the resistance range of the lumped resistor is 50 Ohm to 200 Ohm; the inductance range of the inductor device is 2 nH to 8 nH; and the capacitance range of the capacitor device is 0.1 pF to 0.5 pF.

[0012] According to the above scheme, the period of the FSS unit of the first wave-absorbing layer is 18 mm to 20 mm; the period of the FSS unit of the second wave-transmitting layer is 18 mm to 20 mm; and the period of the FSS unit of the third wave-transmitting layer is 18 mm to 20 mm.

[0013] According to the above scheme, the single-sided copper clad laminates of the first absorbing layer, the second transmitting layer and the third transmitting layer are all based on a dielectric substrate; the dielectric substrate is a glass fiber epoxy resin material with a thickness of 0.25 mm.

[0014] According to the above solution, both the first dielectric isolation layer and the second dielectric isolation layer are made of PMI foam material.

[0015] Furthermore, it transmits electromagnetic waves in the microwave frequency bands of 3.1GHz to 3.4GHz and 5.2GHz to 5.5GHz; and absorbs electromagnetic waves in the microwave frequency band of 8GHz to 12GHz.

[0016] The beneficial effects of the present invention are: 1. The present invention discloses a dual-passband window absorber device. By optimizing its components, assemblies, and configuration, the device can simultaneously address two separate transmission bands and one absorption band within its operating frequency band. The device comprises an absorbing layer and a transparent layer. Inductive and capacitive components are introduced into the absorbing layer to create a double-layered transparent layer, enhancing the transmission bandwidth and steep cutoff selectivity. A second-order bandpass filter is cascaded within the transparent layer to form a dual-transmitting window, achieving both dual-band transmission and broadband absorption. This effectively addresses the difficulty of existing dual-passband window absorbers in simultaneously addressing both out-of-band broadband absorption and in-band broadband transmission. This ensures that the antenna system achieves superior out-of-band RCS reduction and normal in-band signal transmission, contributing to enhanced stealth performance of dual-band conformal antennas.

[0017] 2. The present invention addresses the difficulties of existing dual-band window absorbers, such as high in-band insertion loss and narrow frequency band, and difficulty in widening the out-of-band absorption band. By designing and regulating the frequency point and insertion loss of the dual-band window, the out-of-band transmission rate of the absorbing layer is improved, meeting the insertion loss requirements of multi-layer cascade.

[0018] 3. The transition band of the present invention is highly selective. By introducing inductors and capacitors into the absorbing layer, a wider wave transmission band is achieved at a smaller period, with the achieved wave transmission bandwidths being 3.1 GHz to 3.4 GHz and 5.2 GHz to 5.5 GHz, respectively. The double-layer wave-transmitting layer improves the overall wave transmission bandwidth and selectivity of the wave-transmitting layer, thereby broadening the overall absorbing bandwidth of the dual-band window absorber to 8 GHz to 12 GHz.

[0019] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a schematic three-dimensional diagram of a dual-passband window absorber model according to an embodiment of the present invention.

[0022] Figure 2FIG. 1 is a top view of the absorbing layer of the dual-passband window absorber model according to an embodiment of the present invention.

[0023] Figure 3 It is a top view of the wave-transmitting layer of the dual-passband window absorber model according to an embodiment of the present invention.

[0024] Figure 4 This is a physical picture of the absorbing layer of the dual-passband window absorber according to an embodiment of the present invention.

[0025] Figure 5 This is a physical picture of the wave-transmitting layer of the dual-passband window absorber according to an embodiment of the present invention.

[0026] Figure 6 is the reflectivity S of the dual-band window absorber of the embodiment of the present invention 11 With the wave transmittance S 21 Test result graph.

[0027] In the figure: 1. Jerusalem cross pattern; 2. First absorbing layer; 3. First dielectric isolation layer; 4. Second wave-transmitting layer with square ring and circular ring gap pattern; 5. Second wave-transmitting layer; 6. Second dielectric isolation; 7. Third wave-transmitting layer with square ring and circular ring gap pattern; 8. Third wave-transmitting layer; 9. Lumped resistor; 10. Inductor device; 11. Capacitor device. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] Example 1 See also Figures 1 to 3 A dual-band window absorber device comprises a first absorbing layer 2, a first dielectric isolation layer 3, a second wave-transmitting layer 5, a second dielectric isolation layer 6 and a third wave-transmitting layer 8 arranged in sequence from top to bottom; The first absorbing layer 2 is a single-sided copper-clad laminate with an array of Jerusalem cross patterns 1 periodically arranged in rows and columns. Each Jerusalem cross pattern 1 in the array includes a central square pattern with a zigzag slit and two slits on each of the four sides of the square pattern emanating from the center. A lumped resistor is welded into the slit near the center, while an inductor and capacitor are welded at each end of the slit away from the center. This constitutes the first absorbing layer FSS unit. The second wave-transmitting layer 5 is a single-sided copper-clad plate with an array of second wave-transmitting layer square ring and circular ring gap patterns 4 periodically arranged in rows and columns on the copper foil. Any second wave-transmitting layer square ring and circular ring gap pattern 4 in the array includes a central circular pattern, an outermost square ring pattern, and a filling pattern between the circular pattern and the square ring pattern. A circular ring gap is provided between the circular pattern and the filling pattern, and a square ring gap is provided between the filling pattern and the square ring pattern, thereby forming a second wave-transmitting layer FSS unit. The third wave-transmitting layer 8 is a single-sided copper-clad plate, on which an array of third-layer wave-transmitting layer square ring and circular ring gap patterns 7 are periodically arranged in rows and columns. Any third-layer wave-transmitting layer square ring and circular ring gap pattern 7 in the array includes a circular pattern in the center, an outermost square ring pattern, and a filling pattern between the circular pattern and the square ring pattern. A circular ring gap is provided between the circular pattern and the filling pattern, and a square ring gap is provided between the filling pattern and the square ring pattern, thereby forming a third-layer wave-transmitting layer FSS unit.

[0030] Furthermore, the serpentine gap divides the square pattern into an X-shaped pattern, and the hypotenuse of the X-shaped pattern is a serrated wavy line, and the serrations are all right angles.

[0031] For any gap used for welding an inductor device or a capacitor device, the width of the gap is 0.3 mm to 0.8 mm.

[0032] The line width of the Jerusalem cross pattern 1 is 0.2 mm to 1 mm; the width of the gap used for welding the lumped resistor is 0.5 mm.

[0033] The radius of the circular pattern is 7mm to 9mm; the line width of the fill pattern is 0.1mm to 16.5mm; the line width of the square ring pattern is 0.2mm to 1mm.

[0034] The resistance range of the lumped resistor is 50 Ohm to 200 Ohm; the inductance range of the inductor device is 2 nH to 8 nH; and the capacitance range of the capacitor device is 0.1 pF to 0.5 pF.

[0035] The period of the FSS unit of the first wave-absorbing layer is 18 mm to 20 mm; the period of the FSS unit of the second wave-transmitting layer is 18 mm to 20 mm; and the period of the FSS unit of the third wave-transmitting layer is 18 mm to 20 mm.

[0036] The single-sided copper clad boards of the first wave-absorbing layer 2 , the second wave-transmitting layer 5 and the third wave-transmitting layer 8 are all based on a dielectric substrate; the dielectric substrate is a glass fiber epoxy resin material with a thickness of 0.25 mm.

[0037] The first dielectric isolation layer 3 and the second dielectric isolation layer 6 are both made of PMI foam material.

[0038] Furthermore, it transmits electromagnetic waves in the microwave frequency bands of 3.1GHz to 3.4GHz and 5.2GHz to 5.5GHz; and absorbs electromagnetic waves in the microwave frequency band of 8GHz to 12GHz.

[0039] This embodiment improves the structure and arrangement of each component of the device to provide a window absorber that takes into account both dual-wave-transmitting windows and wave-absorbing windows. Inductive and capacitive devices are introduced into the wave-absorbing layer to construct a double-layer wave-transmitting layer. A second-order bandpass filter is cascaded in the wave-transmitting layer to form a dual-wave-transmitting window, thereby achieving the functions of dual-band wave transmission and broadband wave absorption. This effectively solves the problem that existing dual-passband window absorbers have difficulty in simultaneously taking into account both out-of-band broadband wave absorption and in-band broadband wave transmission. This ensures that the antenna system has good out-of-band RCS reduction and normal in-band signal transmission, which helps to improve the stealth performance of the dual-band common antenna.

[0040] Example 2 See also Figure 4 、 Figure 5 The structure of this embodiment is the same as that of embodiment 1, except that the structure is applied to a specific example. Specifically, it includes: Arranged from top to bottom are the first wave absorbing layer 2, the first dielectric isolation layer 3, the second wave transmitting layer 5, the second dielectric isolation layer 6, and the third wave transmitting layer 8; The first absorbing layer 2 is a single-sided copper-clad laminate with an array of Jerusalem cross patterns 1 periodically arranged in rows and columns. For any Jerusalem cross pattern 1 in the array, the center is a serpentine slot, with two slots positioned on each of the four sides emanating from the center. A lumped resistor is welded into the slot closest to the center, while an inductor and capacitor are welded on either side of the slot farther from the center, forming the first absorbing layer FSS unit. The second wave-transmitting layer 5 is a single-sided copper-clad plate with an array of second wave-transmitting layer square ring and circular ring slot patterns 4 periodically arranged in rows and columns on the copper foil. Any second wave-transmitting layer square ring and circular ring slot pattern 4 in the array includes a circular patch pattern at the center, an annular pattern surrounding the square patch pattern, and an outermost square ring pattern. These three patterns are not directly in contact, thus forming a second wave-transmitting layer FSS unit. The third wave-transmitting layer 8 is a single-sided copper-clad plate with an array of third-layer wave-transmitting layer square ring and circular ring slot patterns 7 periodically arranged in rows and columns on the copper foil. Any third-layer wave-transmitting layer square ring and circular ring slot pattern 7 in the array includes a circular patch pattern at the center, an annular pattern surrounding the square patch pattern, and an outermost square ring pattern. These three patterns do not directly contact each other, thus forming a third-layer wave-transmitting layer FSS unit. The wave absorbing / transmitting device as a whole can absorb and transmit electromagnetic waves.

[0041] The single-sided copper clad laminates of the first wave-absorbing layer 2, the second wave-transmitting layer 5 and the third wave-transmitting layer 8 are all based on a dielectric substrate, and the dielectric substrates used are all glass fiber epoxy resin materials, and the thickness is preferably 0.25 mm; The first dielectric isolation layer 3 and the second dielectric isolation layer 6 are both made of PMI foam material.

[0042] In the first absorbing layer 2 , the width of any gap where a lumped component is welded is 0.5 mm.

[0043] In the first absorbing layer 2, the period of any first absorbing layer FSS unit is 18mm to 20mm; in the second transparent layer, the period of any second transparent layer FSS unit is 18mm to 20mm; in the third transparent layer, the period of any third transparent layer FSS unit is 18mm to 20mm.

[0044] In the first absorbing layer 2, the line width of the Jerusalem cross pattern 1 is 0.2 to 1 mm, the value of any inductor device is 2 nH to 8 nH, the value of any capacitor device is 0.1 pF to 0.5 pF, and the value of any resistor device is 50 Ohm to 200 Ohm. For any gap used to weld the inductor and capacitor devices, the edge of the gap has a protruding copper structure to widen the edge of the gap, and the cross-section has an I-shaped structure.

[0045] The second wave-transmitting layer 5, the radius of the circular pattern is 7mm ~ 9mm; the line width of the annular pattern is 0.1mm ~ 16.5mm; the square ring line width is 0.2mm ~ 1mm; The third wave-transmitting layer 8, the radius of the circular pattern is 7mm ~ 9mm; the line width of the annular pattern is 0.1mm ~ 16.5mm; the square ring line width is 0.2mm ~ 1mm; The wave absorbing / transmitting device as a whole can transmit electromagnetic waves in the microwave frequency bands of 3.1GHz to 3.4GHz and 5.2GHz to 5.5GHz; the wave absorbing / transmitting device as a whole can absorb electromagnetic waves in the microwave frequency band of 8GHz to 12GHz. Figure 6 .

[0046] The above technical solution of this embodiment, compared with the prior art, adopts the method of introducing inductance and capacitance components into the absorbing layer to achieve a wider wave transmission band at a smaller period. By constructing a double-layer wave-transmitting layer, the overall wave transmission bandwidth and selectivity of the wave-transmitting layer are improved, thereby achieving a widened wave absorption bandwidth of the dual-band window absorber. The steepness of the transition bandwidth is represented by the relative transition bandwidth K in this embodiment:

[0047] The relative bandwidth on the right side of the high-frequency wave-transmitting window K =0.25, with high selectivity, and has a good advantage in antenna high selectivity stealth.

[0048] This embodiment primarily transmits waves in the S and C bands, while absorbing waves in the X band. It features a simple design, easy assembly, lightweight, low cost, and a wide absorption frequency band, along with broadband absorption and good selectivity of the transmission window. The first absorbing layer, through design, exhibits the following transmission characteristics: absorb-transmit-absorb-transmit-absorb; the first absorbing layer 2 and the first dielectric isolation layer 3 primarily achieve high-frequency absorption through the ohmic loss of the lumped resistor in the first absorbing layer 2; and both the first absorbing layer 2 and the second-order bandpass filter layer transmit waves in the 3.1 GHz to 3.4 GHz and 5.2 GHz to 5.55 GHz frequency bands, achieving overall wave transmission. Overall, this embodiment is a dual-passband window absorber / wave-transmitting device. The dual-passband absorbing layers can be independently designed based on the requirements for low-frequency transmission and high-frequency stealth, enabling the dual-passband window absorber to achieve high-frequency, broadband absorption while also ensuring broadband transmission.

[0049] The absorbing layer and the wave-transmitting layer used in this embodiment are both single-sided copper-clad boards, and the copper foil is processed into an FSS pattern arranged in rows and columns. The first absorbing layer 2 is mainly composed of a Jerusalem structure and is loaded with lumped devices. The second and third wave-transmitting layers 5 and 8 are square ring and circular ring gap structures of the same size.

[0050] This embodiment improves the design of a multi-layer FSS. Conventional window absorber structures typically consist of two layers, with the first layer being an absorbing layer similar to the first absorbing layer 2 of this embodiment, and the second, or second or third, layers being a second transparent layer 5 or a second transparent layer 5 and a third transparent layer 8 similar to this embodiment. These structures generally share the same theoretical model (i.e., equivalent circuit model). Limited by the design of the absorbing layer, while varying parameter designs can achieve in-band transmission and out-of-band single-band absorption, or in-band transmission and out-of-band dual-band absorption, initially achieving the goal of using window absorbers to transmit in-band signals and reduce out-of-band RCS, the transmission bandwidth is often narrow to achieve the desired low-frequency dual-passband transmission and high-frequency absorption. This embodiment effectively addresses the difficulty of existing dual-passband window absorbers in simultaneously achieving both out-of-band broadband absorption and in-band broadband transmission by introducing inductor and capacitor components into the absorbing layer, thereby ensuring that the antenna system exhibits excellent in-band transmission and out-of-band RCS reduction.

[0051] The design of the first absorbing layer 2 in this embodiment is relatively complex, achieving dual-band transmission and high-frequency absorption. During the design of this first absorbing layer 2, a lumped resistor is used to provide ohmic loss for high-frequency absorption; inductors and capacitors within the "I"-shaped slots provide low-frequency transmission; and a serpentine slot pattern at the center of the unit cell further enhances low-frequency transmission. By rationally arranging these three special structures in a spatial manner, the first absorbing layer 2 is ultimately achieved.

[0052] This embodiment can further control the parameters of each layer structure of the wave absorbing / transmitting device of the composite window absorber, such as line width, side length, inductance value, capacitance value, resistance value, etc., so that the first wave absorbing layer 2 can achieve electromagnetic performance of transmitting waves from 2.88 GHz to 3.48 GHz and 5.04 GHz to 5.68 GHz, and absorbing waves from 8.0 GHz to 12.0 GHz. The second wave-transmitting layer 5 and the third wave-transmitting layer 8 are combined to form a second-order bandpass filter, achieving electromagnetic performance of transmitting waves from 2.876 GHz to 4.024 GHz and 5 GHz to 6.068 GHz, and reflecting waves from 7.3 GHz to 15.0 GHz.

[0053] In the first absorbing layer 2, the value of the lumped resistor affects the absorbing performance from 8.0 GHz to 12.0 GHz; the value of the lumped inductor and lumped capacitor affects the wave transmission performance from 5.2 GHz to 5.5 GHz. The width of the serpentine slot affects the wave transmission performance from 3.1 GHz to 3.4 GHz. In the second and third wave-transmitting layers 5 and 8, the radius of the central circular patch affects the wave transmission performance from 3.1 GHz to 3.4 GHz, and the width of the outermost square ring affects the wave transmission performance from 5.2 GHz to 5.5 GHz. Through simulation optimization, the three-layer structure can achieve the target wave transmission frequency bands of 3.1 GHz to 3.4 GHz and 5.2 GHz to 5.5 GHz in the microwave bands, and the wave absorption frequency band of 8 GHz to 12 GHz in the microwave band.

[0054] In summary, this embodiment utilizes a lossy layer with lumped inductors and capacitors and a lumped resistor as an absorbing layer, and utilizes a second-order bandpass filter as a transparent layer to form a window absorber that has both dual-transmitting windows and absorbing windows, thereby achieving the overall structure's characteristics of low-frequency dual-passband wide-band transmission and high selectivity.

[0055] It should be pointed out that, according to the needs of implementation, the various components described in this application can be split into more components, or two or more components can be combined into new components to achieve the purpose of the present invention.

[0056] The above embodiments are intended only to illustrate the design concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. The scope of protection of the present invention is not limited to the above embodiments. Therefore, any equivalent changes or modifications made based on the principles and design concepts disclosed in the present invention are within the scope of protection of the present invention.

Claims

1. A dual-passband window absorber device, characterized in that: It includes a first wave-absorbing layer, a first dielectric isolation layer, a second wave-transmitting layer, a second dielectric isolation layer and a third wave-transmitting layer arranged in sequence from top to bottom; The first absorbing layer is a single-sided copper-clad board with an array of Jerusalem cross patterns periodically arranged in rows and columns. Any Jerusalem cross pattern in the array consists of a square pattern with a meandering slot in the center and two slots on each of the four sides of the square pattern starting from the center. A lumped resistor is welded in the slot near the center, and an inductor and capacitor are welded at both ends of the slot away from the center, forming the first absorbing layer FSS unit. The second wave-transmitting layer is a single-sided copper-clad laminate with an array of square and circular ring gap patterns periodically arranged in rows and columns. Any square ring and circular ring gap pattern in the array includes a central circular pattern, an outermost square ring pattern, and a filling pattern between the circular and square ring patterns. A circular gap is provided between the circular pattern and the filling pattern, and a square gap is provided between the filling pattern and the square ring pattern. This constitutes the FSS unit of the second wave-transmitting layer. The third wave-transmitting layer is a single-sided copper-clad board with an array of square-ring and circular-ring gap patterns periodically arranged in rows and columns on the copper foil. Any square-ring and circular-ring gap pattern in the array includes a circular pattern in the center, an outermost square-ring pattern, and a filling pattern between the circular and square ring patterns. A circular gap is provided between the circular pattern and the filling pattern, and a square gap is provided between the filling pattern and the square ring pattern. This constitutes the FSS unit of the third wave-transmitting layer.

2. The dual-passband window absorber device according to claim 1, characterized in that: The zigzag gap divides the square pattern into an X-shaped pattern. The hypotenuse of the X-shaped pattern is a jagged wavy line, and the teeth are all right angles.

3. The dual-passband window absorber device according to claim 1, characterized in that: For any gap used for welding an inductor device or a capacitor device, the width of the gap is 0.3 mm to 0.8 mm.

4. The dual-passband window absorber device according to claim 1, characterized in that: The line width of the Jerusalem cross pattern is 0.2mm to 1mm; The width of the gap for soldering the lumped resistor is 0.5 mm.

5. The dual-passband window absorber device according to claim 1, characterized in that: The radius of the circular pattern is 7mm to 9mm; the line width of the fill pattern is 0.1mm to 16.5mm; the line width of the square ring pattern is 0.2mm to 1mm.

6. The dual-passband window absorber device according to claim 1, characterized in that: The resistance range of the lumped resistor is 50Ohm to 200Ohm; The inductance value range of the inductor device is 2nH to 8nH; The capacitance value range of the capacitor device is 0.1pF to 0.5pF.

7. The dual-passband window absorber device according to claim 1, characterized in that: The period of the FSS unit in the first absorbing layer is 18 mm to 20 mm; The period of the FSS unit in the second wave-transparent layer is 18 mm to 20 mm; The period of the FSS unit in the third wave-transparent layer is 18 mm to 20 mm.

8. The dual-passband window absorber device according to claim 1, characterized in that: The single-sided copper clad laminates of the first absorbing layer, the second transmitting layer and the third transmitting layer are all based on a dielectric substrate; the dielectric substrate is a glass fiber epoxy resin material with a thickness of 0.25 mm.

9. The dual-passband window absorber device according to claim 1, characterized in that: The first dielectric isolation layer and the second dielectric isolation layer are both made of PMI foam material.

10. The dual-passband window absorber device according to any one of claims 1 to 9, characterized in that: Transmits electromagnetic waves in the microwave frequency bands of 3.1GHz~3.4GHz and 5.2GHz~5.5GHz; Absorbs electromagnetic waves in the microwave frequency band of 8GHz to 12GHz.

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