Dual-polarization band-pass frequency selection unit with angle selectivity and wave absorber

Abstract

The invention discloses a dual-polarization band-pass frequency selection unit with angle selectivity and a wave absorber. The dual-polarized band-pass frequency selection unit comprises a first metal layer, a first dielectric substrate, a second dielectric substrate, a second metal layer, a third metal layer, a third dielectric substrate, a fourth metal layer, a fourth dielectric substrate, a fifth metal layer and a fifth dielectric substrate which are sequentially arranged from top to bottom. The wave absorber comprises a plurality of periodically arranged dual-polarized band-pass frequency selection units. The wave absorbing rate of the dual-polarization band-pass frequency selection unit in a certain frequency band range is larger than or equal to 80%, the wave absorbing range of the dual-polarization band-pass frequency selection unit covers the X wave band and gives consideration to the KU wave band, electromagnetic waves in the large frequency band range are absorbed, and the stealth capacity of a system of the dual-polarization band-pass frequency selection unit is effectively improved. The wave absorber and the angle selection surface are combined, out-of-band wave absorption and in-band angle selection are achieved, and the dual-polarization characteristic is achieved. The problem of co-frequency interference in a traditional frequency selection wave absorber band is solved, and the frequency selection wave absorber has huge application value in the field of radar stealth.

Description

Technical Field

[0001] This invention belongs to the field of radar stealth technology, specifically relating to an angle-selective dual-polarized bandpass frequency selection unit and absorber. Background Technology

[0002] A frequency-selective absorber (FSR) is a periodic electromagnetic structure integrated with a frequency-selective surface (FSS) and a circuit-analog absorber (CAA). Essentially a space filter, its design ensures normal signal transmission within the operating frequency band while absorbing out-of-band incident radar waves instead of reflecting them, thus comprehensively reducing electromagnetic scattering. It possesses electromagnetic characteristics of in-band transmission and out-of-band absorption. This microwave device is widely used in radar radomes, space filters, and wireless communication.

[0003] With the rapid development of modern electronic technology, the electromagnetic environment is becoming increasingly complex, and radar technology is constantly being upgraded. In modern communication, the threat of radar to target detection continues to increase, and electromagnetic interference can also cause aircraft to lose their capabilities. Against this backdrop, stealth technology has become crucial for improving target survivability and anti-electromagnetic interference performance, and its further development is urgently needed. Radar Cross Section (RCS) is an important indicator for measuring stealth performance, and how to reduce RCS has always been a difficult problem to solve. For example, stealth design, the use of traditional absorbing materials, and plasma stealth technology can reduce RCS to some extent, but their drawbacks cannot be ignored. Stealth design often comes with the sacrifice of function, disrupting aerodynamic performance or internal space layout; most absorbing materials have narrow frequency bands and poor compatibility, effective only in specific narrow frequency bands, making it difficult to cover multi-band radar, and full-band absorption will block its own communication signals, making it incompatible with the normal operation of equipment. Moreover, to achieve broadband absorption, absorbing materials often need to be stacked in multiple layers, leading to increased weight and affecting maneuverability; plasma stealth technology has poor stability, as the concentration and distribution of plasma are easily affected by environmental factors such as temperature and air pressure, making it difficult to maintain stable stealth performance. Secondly, there are also energy consumption and compatibility issues. Generating plasma requires a large amount of energy, and the high-temperature plasma can interfere with the normal operation of its own electronic equipment. Therefore, how to balance radar stealth, environmental adaptability, and electromagnetic compatibility has become a hot research topic in the industry. More and more researchers are beginning to focus on reflectors / absorbing devices that are compatible with communication and stealth requirements, reducing RCS without affecting their own communication functions, taking into account both electromagnetic wave shielding within the operating frequency band and long-range communication capabilities, and better adapting to complex and changing electromagnetic environments.

[0004] Against the backdrop of rapid development in modern communication technology, the electromagnetic environment in which aircraft operate is becoming increasingly complex. Traditional stealth technology is no longer sufficient to meet the survival requirements of modern aircraft. In particular, traditional stealth technology often encounters co-channel interference within the passband where it achieves stealth effectiveness, which greatly limits its application effectiveness in complex battlefield environments. To solve the co-channel interference problem of stealth technology within the passband, it is urgent to develop new technical solutions. This is not only key to improving the anti-interference capability of communication systems, but also an essential requirement for ensuring the survivability of aircraft. Existing stealth technologies, such as angle-selective surfaces, often focus on solving the co-channel interference problem at the expense of their own stealth effectiveness, and can no longer meet the stealth requirements of current flight environments. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides an angle-selective dual-polarized bandpass frequency selection unit and absorber. The technical problem to be solved by this invention is achieved through the following technical solution: In a first aspect, the present invention provides an angle-selective dual-polarized bandpass frequency selection unit, comprising: The layers arranged from top to bottom are: a first metal layer, a first dielectric substrate, a second dielectric substrate, a second metal layer, a third metal layer, a third dielectric substrate, a fourth metal layer, a fourth dielectric substrate, a fifth metal layer, and a fifth dielectric substrate; wherein, The first metal layer is composed of a first hexagonal patch structure, a first / λ short-circuit stub, and a first patch resistor, and is disposed on the front side of the first dielectric substrate; the center of the first hexagonal patch structure is consistent with the center of the cell; the first / λ short-circuit stubs are respectively loaded inward on the three non-adjacent sides of the first hexagonal patch structure; the first patch resistors are respectively connected to the three sides of the first hexagonal patch structure where the first / λ short-circuit stubs are not disposed; λ represents the operating wavelength; The second metal layer is composed of a second hexagonal patch structure, a second / λ short-circuit stub, a component mounting parallel stub, a second patch resistor, and a patch inductor, and is disposed on the back side of the second dielectric substrate; the center of the second hexagonal patch structure is consistent with the center of the cell; the second / λ short-circuit stubs are respectively loaded outward on the three non-adjacent sides of the second hexagonal patch structure; the component mounting parallel stubs are printed on the three sides of the second hexagonal patch structure where the second / λ short-circuit stubs are not provided; the second patch resistors are respectively connected to the inner stubs of the component mounting parallel stubs; and the patch inductors are respectively connected to the outer stubs of the component mounting parallel stubs. The third metal layer is composed of an outer hexagonal patch structure and an inner hexagonal patch structure, and is disposed on the front side of the third dielectric substrate; the center of both the outer and inner hexagonal patch structures of the third metal layer is consistent with the center of the cell. The fourth metal layer is composed of a first hexagonal slot structure and is disposed on the front side of the fourth dielectric substrate, with the center of the first hexagonal slot structure coinciding with the center of the unit. The fifth metal layer is composed of a second hexagonal slot structure and is disposed on the front side of the fifth dielectric substrate, with the center of the second hexagonal slot structure coinciding with the center of the unit.

[0006] In one embodiment of the present invention, the first metal layer is an axisymmetric structure, the first hexagonal patch structure is both an axisymmetric and a centrosymmetric structure, and the first / λ short-circuit stub is an axisymmetric structure.

[0007] In one embodiment of the present invention, the first / λ short-circuit stub is loaded vertically inward at the midpoint of the three non-adjacent sides of the first hexagonal patch structure.

[0008] In one embodiment of the present invention, the second metal layer is an axisymmetric structure, the second hexagonal patch structure is both an axisymmetric and a centrosymmetric structure, the second / λ short-circuit stub is an axisymmetric structure, and the component mounted parallel stub is an axisymmetric structure.

[0009] In one embodiment of the present invention, the second / λ short-circuit stub is loaded vertically outward at the midpoint of the three non-adjacent sides of the second hexagonal patch structure.

[0010] In one embodiment of the invention, the element is mounted with parallel stubs vertically printed at the midpoints of the three sides of the second hexagonal patch structure where no second / λ short-circuit stubs are provided.

[0011] In one embodiment of the present invention, the third metal layer is both an axisymmetric structure and a centrosymmetric structure, the outer ring hexagonal patch structure is both an axisymmetric structure and a centrosymmetric structure, and the inner ring hexagonal patch structure is both an axisymmetric structure and a centrosymmetric structure.

[0012] In one embodiment of the present invention, the materials of the first dielectric substrate, the second dielectric substrate, the third dielectric substrate, the fourth dielectric substrate and the fifth dielectric substrate all include polytetrafluoroethylene (PTFE) FB. The first dielectric substrate, the second dielectric substrate, the third dielectric substrate, the fourth dielectric substrate, and the fifth dielectric substrate are all hexagonal in shape.

[0013] In one embodiment of the present invention, the materials of the first metal layer, the second metal layer, the third metal layer, the fourth metal layer, and the fifth metal layer all include: Copper (Cu), aluminum (Al), or gold (Au).

[0014] In a second aspect, the present invention provides a microwave absorber, the microwave absorber comprising: A periodically arranged, angle-selective, dual-polarized bandpass frequency selection unit as described in the first aspect; wherein, and It is an integer greater than or equal to.

[0015] The beneficial effects of this invention are: 1. In the solution provided by the present invention, the angle-selective dual-polarized bandpass frequency selection unit has an absorption rate of ≥80% in the frequency bands of 7.6GHz-11.6GHz and 16GHz-18.3GHz. Its absorption range covers the X-band and also takes into account the Ku-band, thereby achieving absorption of electromagnetic waves in a wide frequency range and effectively improving the stealth capability of its own system.

[0016] 2. The angle-selective dual-polarized bandpass frequency-selective absorber still retains its absorption function on both sides in the angular domain where the electromagnetic wave incident angle θ < 50°. Therefore, the structure has excellent angular stability, which maximizes the stealth performance of the system.

[0017] 3. This angle-selective dual-polarized bandpass frequency-selective absorber exhibits angle selectivity near 14.3 GHz within the band: it achieves wave transmission (transmission coefficient ≤ -1 dB) in the angular domain of 0°-3° electromagnetic wave incident angle, a transition angular domain of 3°-11.5° (-1 dB < transmission coefficient ≤ 10 dB), and a stopband angular domain of 11.5°-50° (-10 dB < transmission coefficient). Therefore, this absorber possesses excellent narrow angular domain and narrow transition characteristics, solving the problem of co-frequency interference within the band, improving the overall stealth capability of the system, and enabling the absorber to cope with more complex working environments.

[0018] 4. The angle-selective dual-polarization bandpass frequency-selective absorber adopts a centrally symmetric and axisymmetric unit structure. This design enables the absorber structure to have good polarization stability. The incident waves under TE polarization and TM polarization have the same transmission / reflection curves at different incident angles, so that the function and state of the structure remain consistent under the two polarizations.

[0019] 5. This angle-selective dual-polarized bandpass frequency selective absorber uses a polytetrafluoroethylene F4B flexible dielectric substrate, which has a certain conformal capability, giving it greater potential for practical application value.

[0020] 6. All of these angle-selective dual-polarized bandpass frequency selective absorbers are single-sided structures, meaning that the metal pattern of the structure is only engraved on one side of the dielectric substrate. This greatly reduces the manufacturing difficulty and cost of the absorber, facilitates large-scale integration, and has potential practical value. Attached Figure Description

[0021] Figure 1 A perspective view of an angle-selective dual-polarization bandpass frequency selection unit provided in an embodiment of the present invention; Figure 2 A side view of an angle-selective dual-polarization bandpass frequency selection unit provided in an embodiment of the present invention; Figure 3 This is a front view of the first metal layer in an angle-selective dual-polarization bandpass frequency selection unit provided in an embodiment of the present invention. Figure 4 This is a front view of the second metal layer in an angle-selective dual-polarization bandpass frequency selection unit provided in an embodiment of the present invention. Figure 5 This is a front view of the third metal layer in an angle-selective dual-polarization bandpass frequency selection unit provided in an embodiment of the present invention. Figure 6 This is a front view of the fourth metal layer in an angle-selective dual-polarization bandpass frequency selection unit provided in an embodiment of the present invention. Figure 7 This is a front view of the fifth metal layer in an angle-selective dual-polarization bandpass frequency selection unit provided in an embodiment of the present invention. Figure 8 A perspective view of a wave absorber provided in an embodiment of the present invention; Figure 9 The image shows a simulation of the scattering parameter curves of an absorber in TE polarization mode, as provided in an embodiment of the present invention. Figure 10 The image shows a simulation of the scattering parameter curves of an absorber in TM polarization mode, as provided in an embodiment of the present invention. Figure 11 This is a simulation diagram of the absorption rate of an absorber in TE polarization mode provided in an embodiment of the present invention. Figure 12 This is a simulation diagram of the absorption rate of an absorber in TM polarization mode provided in an embodiment of the present invention. Figure 13 This is a simulation diagram of the performance stability of the absorbing band angle on both sides of an absorber in TE polarization mode, provided by an embodiment of the present invention. Figure 14 This is a simulation diagram of the performance stability of the absorbing band angle on both sides of an absorber in TM polarization mode, provided by an embodiment of the present invention. Figure 15 This is a simulation diagram of the absorption rate angle stability of an absorber in TE polarization mode, provided by an embodiment of the present invention. Figure 16This is a simulation diagram of the absorption rate angle stability of an absorber in TM polarization mode, provided by an embodiment of the present invention. Figure 17 A simulation diagram of the performance of an absorber in TE polarization mode near 14.3 GHz, provided in an embodiment of the present invention; Figure 18 The image shows a performance simulation of the angle selection curve of an absorber in TM polarization mode near 14.3 GHz, provided in an embodiment of the present invention.

[0022] Figure Labels 1-First metal layer, 11-First hexagonal patch structure, 12-First 1 / λ short-circuit stub, 13-First patch resistor, 2-First dielectric substrate, 3-Second dielectric substrate, 4-Second metal layer, 41-Second hexagonal patch structure, 42-Second 1 / λ short-circuit stub, 43-Component mounted parallel stub, 44-Second patch resistor, 45-Patch inductor, 5-Third metal layer, 51-Outer ring hexagonal patch structure, 52-Inner ring hexagonal patch structure, 6-Third dielectric substrate, 7-Fourth metal layer, 71-First hexagonal slot structure, 8-Fourth dielectric substrate, 9-Fifth metal layer, 91-First hexagonal slot structure, 10-Fifth dielectric substrate. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0024] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a more in-depth and concrete understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the technical solutions of the present invention.

[0025] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes said element.

[0026] This invention provides an angle-selective dual-polarized bandpass frequency selection unit and absorber.

[0027] The following is a description of a method provided by an embodiment of the present invention.

[0028] Figure 1 A 3D view of a dual-polarization bandpass frequency selection unit. Figure 2 This is a side view of a dual-polarized bandpass frequency selection unit. The embodiment of the present invention provides a dual-polarized bandpass frequency selection unit with angle selectivity, such as... Figure 1 and Figure 2 As shown, it may include: The following layers are arranged sequentially from top to bottom: a first metal layer 1, a first dielectric substrate 2, a second dielectric substrate 3, a second metal layer 4, a third metal layer 5, a third dielectric substrate 6, a fourth metal layer 7, a fourth dielectric substrate 8, a fifth metal layer 9, and a fifth dielectric substrate 10; wherein, The first metal layer 1 is composed of a first hexagonal patch structure 11, a first 1 / λ short-circuit stub 12, and a first patch resistor 13, and is disposed on the front side of the first dielectric substrate 2; the center of the first hexagonal patch structure 11 is consistent with the center of the cell, the first 1 / λ short-circuit stub 12 is respectively loaded inward on the three non-adjacent sides of the first hexagonal patch structure 11, and the first patch resistor 13 is respectively connected to the three sides of the first hexagonal patch structure 11 where the first 1 / λ short-circuit stub 12 is not disposed; λ represents the operating wavelength; The second metal layer 4 is composed of a second hexagonal patch structure 41, a second 1 / λ short-circuit stub 42, a component mounting parallel stub 43, a second patch resistor 44, and a patch inductor 45, and is disposed on the back side of the second dielectric substrate 3. The center of the second hexagonal patch structure 41 is consistent with the center of the cell. The second 1 / λ short-circuit stub 42 is respectively loaded outward on the three non-adjacent sides of the second hexagonal patch structure 41. The component mounting parallel stub 43 is printed on the three sides of the second hexagonal patch structure 41 where the second 1 / λ short-circuit stub 42 is not disposed. The second patch resistor 44 is respectively connected to the inner stub of the component mounting parallel stub 43, and the patch inductor 45 is respectively connected to the outer stub of the component mounting parallel stub 43. The third metal layer 5 is composed of an outer hexagonal patch structure 51 and an inner hexagonal patch structure 52, and is disposed on the front side of the third dielectric substrate 6; the centers of the outer hexagonal patch structure 51 and the inner hexagonal patch structure 52 of the third metal layer 5 are both aligned with the center of the cell. The fourth metal layer 7 is composed of a first hexagonal slot structure 71 and is disposed on the front side of the fourth dielectric substrate 8. The center of the first hexagonal slot structure 71 is consistent with the center of the cell. The fifth metal layer 9 is composed of a second hexagonal slot structure 91 and is disposed on the front side of the fifth dielectric substrate 10. The center of the second hexagonal slot structure 91 is consistent with the center of the cell.

[0029] Specifically, the front view of the first metal layer in the dual-polarized bandpass frequency selection unit provided in this embodiment of the invention is as follows: Figure 3 As shown, the first metal layer 1 can be an axisymmetric structure, the first hexagonal patch structure 11 can be either an axisymmetric or centrosymmetric structure, and the first 1 / λ short-circuit stub 12 can be an axisymmetric structure. The first 1 / λ short-circuit stub 12 is loaded vertically inward at the midpoint of the three non-adjacent sides of the first hexagonal patch structure 11. There are three first 1 / λ short-circuit stubs 12 in the first metal layer 1, and three first patch resistors 13.

[0030] Specifically, the front view of the second metal layer in the dual-polarized bandpass frequency selection unit provided in this embodiment of the invention is as follows: Figure 4 As shown, the second metal layer 4 can be an axisymmetric structure, the second hexagonal patch structure 41 can be either an axisymmetric or centrosymmetric structure, the second 1 / λ short-circuit stub 42 can be an axisymmetric structure, and the component-mounted parallel stub 43 can be an axisymmetric structure. The second 1 / λ short-circuit stub 42 is vertically outwardly loaded at the midpoint of the three non-adjacent sides of the second hexagonal patch structure 41. The component-mounted parallel stub 43 is vertically printed at the midpoint of the three sides of the second hexagonal patch structure 41 where the second 1 / λ short-circuit stub 42 is not located. In the second metal layer 4, there are three second 1 / λ short-circuit stubs 42, three component-mounted parallel stubs 43, three second surface-mount resistors 44, and three surface-mount inductors 45.

[0031] Specifically, the front view of the third metal layer in the dual-polarized bandpass frequency selection unit provided in this embodiment of the invention is as follows: Figure 5 As shown, it can be seen that in the third metal layer 5, the third metal layer 5 can be either an axisymmetric structure or a centrosymmetric structure. The outer ring hexagonal patch structure 51 can be either an axisymmetric structure or a centrosymmetric structure, and the inner ring hexagonal patch structure 52 can be either an axisymmetric structure or a centrosymmetric structure.

[0032] Specifically, the front view of the fourth metal layer in the dual-polarized bandpass frequency selection unit provided in this embodiment of the invention is as follows: Figure 6 As shown, the fourth metal layer 7 can be either an axisymmetric or a centrosymmetric structure. The first hexagonal slot structure 71 can also be either an axisymmetric or a centrosymmetric structure.

[0033] Specifically, the front view of the fifth metal layer in the dual-polarized bandpass frequency selection unit provided in this embodiment of the invention is as follows: Figure 7 As shown, the fifth metal layer 9 can be either an axisymmetric or a centrosymmetric structure. The second hexagonal slot structure 91 can also be either an axisymmetric or a centrosymmetric structure.

[0034] In the dual-polarized bandpass frequency selection unit proposed in the embodiments of the present invention, the materials of the first dielectric substrate 2, the second dielectric substrate 3, the third dielectric substrate 6, the fourth dielectric substrate 8 and the fifth dielectric substrate 10 may all include polytetrafluoroethylene F4B. The first dielectric substrate 2, the second dielectric substrate 3, the third dielectric substrate 6, the fourth dielectric substrate 8, and the fifth dielectric substrate 10 can all be in the shape of a regular hexagon.

[0035] The side length of the regular hexagon in the surface dimensions of the first dielectric substrate 2, the second dielectric substrate 3, the third dielectric substrate 6, the fourth dielectric substrate 8, and the fifth dielectric substrate 10 can be 4 mm.

[0036] The materials of the first metal layer 1, the second metal layer 4, the third metal layer 5, the fourth metal layer 7, and the fifth metal layer 9 can all include: copper (Cu), aluminum (Al), gold (Au), or other metals.

[0037] Optionally, the first dielectric substrate 2 and the third dielectric substrate 6 are made of F4B flexible material with a relative permittivity of 3 and a loss factor of 0.0018. The second dielectric substrate 3 is made of F4B flexible material with a relative permittivity of 2.6 and a loss factor of 0.0018. The fourth dielectric substrate 8 and the fifth dielectric substrate 10 are made of F4B flexible material with a relative permittivity of 6.15 and a loss factor of 0.0025. Furthermore, the thickness of the first dielectric substrate 2, the second dielectric substrate 3, and the third dielectric substrate 6 can be 0.508 mm, and the thickness of the fourth dielectric substrate 8 and the fifth dielectric substrate 10 can be 0.254 mm. A first air layer exists between the first dielectric substrate 2 and the second dielectric substrate 3; a second air layer exists between the second dielectric substrate 3 and the third dielectric substrate 6; a third air layer exists between the third dielectric substrate 6 and the fourth dielectric substrate 8; and a fourth air layer exists between the fourth dielectric substrate 8 and the fifth dielectric substrate 10. The thicknesses of the first air layer, the second air layer, the third air layer, and the fourth air layer can be 1.488 mm, 2.32 mm, 1.39 mm, and 11.09 mm, respectively. The thicknesses of the first metal layer 1, the second metal layer 4, the third metal layer 5, the fourth metal layer 7, and the fifth metal layer 9 can be 0.018 mm.

[0038] Optionally, the detailed geometric parameters corresponding to the dual-polarized bandpass frequency selection unit proposed in the embodiments of the present invention can be found in Table 1, which shows the geometric parameter table.

[0039] Table 1 shows the geometric parameters.

[0040] Understandably, the dual-polarized bandpass frequency selection unit proposed in this embodiment of the invention is very small in size, with the surface of the unit being only a regular hexagon with a side length of 4mm, which meets the current trend of device miniaturization and the needs of processing technology.

[0041] The angle-selective dual-polarized bandpass frequency selection unit proposed in this invention has an absorption rate of ≥80% in the 7.6GHz-11.6GHz and 16GHz-18.3GHz frequency bands. Its absorption range covers the X-band and also takes into account the Ku-band, thereby achieving absorption of electromagnetic waves in a wide frequency range and effectively improving the stealth capability of its own system.

[0042] Secondly, corresponding to the above-described embodiments of the dual-polarized bandpass frequency selection unit, this embodiment of the invention also provides an absorber, such as... Figure 8 As shown, it may include: A periodically arranged, angle-selective, dual-polarized bandpass frequency selection unit as described in the first aspect; wherein, and The value is an integer greater than or equal to 1. In this embodiment of the invention, the absorber has a surface structure comprising 5×5 units. In other embodiments, the absorber may include 10×10, 20×20, 30×30, 40×40 or more angle-selective dual-polarized bandpass frequency selection units.

[0043] To further verify the performance of the absorber proposed in the embodiments of the present invention, the absorber was subjected to several performance simulation analyses using the simulation software CST.

[0044] Please see Figures 9-12 , Figure 9 This is a performance simulation graph of the scattering parameter curve of the absorber provided in the embodiment of the present invention in TE polarization mode. Figure 10 This is a performance simulation graph of the scattering parameter curve of the absorber provided in the embodiment of the present invention in TM polarization mode. Figure 11 This is a simulation diagram of the absorption rate of the absorber provided in the embodiment of the present invention in TE polarization mode. Figure 12 The above is a simulation diagram of the absorption rate of the absorber provided in the embodiment of the present invention in TM polarization mode.

[0045] from Figure 9 and Figure 11As can be seen from the transmission coefficient, reflection coefficient, and absorption rate, the absorber proposed in this embodiment of the invention has an absorption rate ≥80% in the 7.6GHz-11.6GHz and 16GHz-18.3GHz frequency bands, and both the transmission coefficient and reflection coefficient are ≤-10dB. This frequency band is the operating frequency band for frequency-selective absorbers. Therefore, it can be understood that, in TE polarization mode, the absorber proposed in this embodiment of the invention has a good absorption effect on signals in the frequency range of 7.6GHz-11.6GHz and 16GHz-18.3GHz.

[0046] from Figure 10 and Figure 12 As can be seen from the transmission coefficient, reflection coefficient, and absorption rate, the absorber proposed in this embodiment of the invention has an absorption rate ≥80% in the 7.6GHz-11.6GHz and 16GHz-18.3GHz frequency bands, and both the transmission coefficient and reflection coefficient are ≤-10dB. This frequency band is the absorption operating frequency band for frequency-selective absorbers. Therefore, it can be understood that, in TM polarization mode, the absorber proposed in this embodiment of the invention has a good absorption effect on signals in the frequency range of 7.6GHz-11.6GHz and 16GHz-18.3GHz.

[0047] Furthermore, comprehensive Figures 9-12 As can be seen from the performance simulation diagram, the absorber proposed in this embodiment of the invention has good absorption performance in TE mode and TM mode, the absorption frequency covers the X band and also takes into account the Ku band, and has excellent polarization stability.

[0048] Furthermore, to study the angular stability of the absorbing band corresponding to the absorber proposed in this embodiment of the invention, the absorber was irradiated with incident waves at incident angles of 0°, 10°, 20°, 30°, 40°, and 50° in TE and TM modes, and the frequency characteristics of the absorber were obtained. Please refer to [link to relevant documentation]. Figures 13-16 , Figure 13 This is a simulation diagram showing the performance stability of the absorbing band angle on both sides of the absorber provided in the embodiment of the present invention under TE polarization mode. Figure 14 This is a simulation diagram showing the performance stability of the absorbing band angle on both sides of the absorber provided in the embodiment of the present invention under TM polarization mode. Figure 15 This is a simulation diagram of the absorption rate angle stability of the absorber provided in the embodiment of the present invention under TE polarization mode. Figure 16 The above is a simulation diagram of the absorption rate angle stability of the absorber provided in the embodiment of the present invention under TM polarization mode.

[0049] The absorber proposed in this invention exhibits good angular stability in its absorption bands in the X-band and Ku-band. Even under electromagnetic incident wave irradiation at different angles, corresponding absorption bands still exist, and its absorption performance deviation is within an acceptable range, demonstrating excellent absorption and anti-interference capabilities. Figures 13 to 16 As can be seen from the performance simulation diagram, when the absorber is irradiated with incident waves at angles of 0°, 10°, 20°, 30°, 40° and 50° in TE mode and TM mode, there are corresponding absorption bands in both the X-band and Ku-band, which shows excellent absorption performance. Therefore, the absorber proposed in this embodiment of the invention has excellent angular stability.

[0050] Furthermore, in order to study the angular selectivity of the absorber proposed in this embodiment of the invention, the angular characteristics of the absorber can be obtained by scanning the incident angle in TE mode and TM mode. Please refer to [link to relevant documentation]. Figure 17 and Figure 18 , Figure 17 This is a performance simulation diagram of the angle selection curve of the absorber provided in the embodiment of the present invention near 14.3 GHz in TE polarization mode. Figure 18 The simulation graph shows the performance of the absorber provided in this embodiment of the invention at an angle selectivity curve near 14.3 GHz in TM polarization mode. It can be seen that the absorber exhibits excellent in-band angle selectivity near 14.3 GHz: it achieves wave transmission (transmission coefficient ≤ -1 dB) in the angular domain of 0°-3° electromagnetic wave incident angle, a transition angular domain of 3°-11.5° (-1 dB < transmission coefficient ≤ 10 dB), and a stopband angular domain of 11.5°-50° (-10 dB < transmission coefficient), possessing excellent narrow angular domain and narrow transition characteristics. Figure 17 and Figure 18 As can be seen from the performance simulation diagram, the absorber proposed in this embodiment of the invention has excellent narrow-angle domain, narrow transition, and dual-polarization characteristics around 14.3GHz in both TE and TM modes. Therefore, the absorber proposed in this embodiment of the invention has excellent angle selectivity characteristics.

[0051] In summary, the absorber proposed in this invention exhibits excellent absorption performance in the 7.6GHz-11.6GHz and 16GHz-18.3GHz frequency bands, and demonstrates outstanding angular selectivity around 14.3GHz within the band. It can simultaneously absorb electromagnetic waves from both the X-band and Ku-band, providing electromagnetic protection against radio frequency systems. Its excellent angular selectivity within the operating band solves the problem of co-channel interference within the band, and it achieves excellent stealth performance in complex working environments.

[0052] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A dual-polarized bandpass frequency selection unit with angle selectivity, characterized in that, include: The components arranged from top to bottom are: a first metal layer (1), a first dielectric substrate (2), a second dielectric substrate (3), a second metal layer (4), a third metal layer (5), a third dielectric substrate (6), a fourth metal layer (7), a fourth dielectric substrate (8), a fifth metal layer (9), and a fifth dielectric substrate (10); wherein, The first metal layer (1) is composed of a first hexagonal patch structure (11), a first 1 / λ short-circuit stub (12), and a first patch resistor (13), and is disposed on the front side of the first dielectric substrate (2); the center of the first hexagonal patch structure (11) is consistent with the center of the unit, the first 1 / λ short-circuit stub (12) is loaded inward on the three non-adjacent sides of the first hexagonal patch structure (11), and the first patch resistor (13) is connected to the three sides of the first hexagonal patch structure (11) where the first 1 / λ short-circuit stub (12) is not disposed; λ represents the operating wavelength; The second metal layer (4) is composed of a second hexagonal patch structure (41), a second 1 / λ short-circuit stub (42), a component mounting parallel stub (43), a second patch resistor (44), and a patch inductor (45), and is disposed on the back side of the second dielectric substrate (3); the center of the second hexagonal patch structure (41) is consistent with the center of the cell, the second 1 / λ short-circuit stub (42) is loaded outward on the three non-adjacent sides of the second hexagonal patch structure (41), the component mounting parallel stub (43) is printed on the three sides of the second hexagonal patch structure (41) where the second 1 / λ short-circuit stub (42) is not disposed, the second patch resistor (44) is connected to the inner stub of the component mounting parallel stub (43), and the patch inductor (45) is connected to the outer stub of the component mounting parallel stub (43); The third metal layer (5) is composed of an outer ring hexagonal patch structure (51) and an inner ring hexagonal patch structure (52), and is disposed on the front side of the third dielectric substrate (6); the center of the third metal layer (5) and the center of the outer ring hexagonal patch structure (51) and the inner ring hexagonal patch structure (52) are both consistent with the center of the unit. The fourth metal layer (7) is composed of a first hexagonal slot structure (71) and is disposed on the front side of the fourth dielectric substrate (8). The center of the first hexagonal slot structure (71) is consistent with the center of the unit. The fifth metal layer (9) is composed of a second hexagonal slot structure (91) and is disposed on the front side of the fifth dielectric substrate (10). The center of the second hexagonal slot structure (91) is consistent with the center of the unit.

2. The angle-selective dual-polarization bandpass frequency selection unit according to claim 1, characterized in that, In the first metal layer (1), the first metal layer (1) is an axisymmetric structure, the first hexagonal patch structure (11) is both an axisymmetric structure and a centrally symmetric structure, and the first 1 / λ short-circuit stub (12) is an axisymmetric structure.

3. The angle-selective dual-polarization bandpass frequency selection unit according to claim 1, characterized in that, The first 1 / λ short-circuit stub (12) is loaded vertically inward at the midpoint of the three non-adjacent sides of the first hexagonal patch structure (11).

4. The angle-selective dual-polarization bandpass frequency selection unit according to claim 1, characterized in that, In the second metal layer (4), the second metal layer (4) is an axisymmetric structure, the second hexagonal patch structure (41) is both an axisymmetric structure and a centrally symmetric structure, the second 1 / λ short-circuit stub (42) is an axisymmetric structure, and the component-mounted parallel stub (43) is an axisymmetric structure.

5. The angle-selective dual-polarization bandpass frequency selection unit according to claim 1, characterized in that, The second 1 / λ short-circuit stub (42) is loaded vertically outward at the midpoint of the three non-adjacent sides of the second hexagonal patch structure (41).

6. The angle-selective dual-polarization bandpass frequency selection unit according to claim 1, characterized in that, The component is mounted on a parallel stub (43) and is vertically printed at the midpoint of the three sides of the second hexagonal patch structure (41) where the second 1 / λ short-circuit stub (42) is not provided.

7. The angle-selective dual-polarization bandpass frequency selection unit according to claim 1, characterized in that, In the third metal layer (5), the third metal layer (5) is both an axisymmetric structure and a centrosymmetric structure, the outer ring hexagonal patch structure (51) is both an axisymmetric structure and a centrosymmetric structure, and the inner ring hexagonal patch structure (52) is both an axisymmetric structure and a centrosymmetric structure.

8. The angle-selective dual-polarization bandpass frequency selection unit according to claim 1, characterized in that, The materials of the first dielectric substrate (2), the second dielectric substrate (3), the third dielectric substrate (6), the fourth dielectric substrate (8), and the fifth dielectric substrate (10) all include polytetrafluoroethylene F4B; The first dielectric substrate (2), the second dielectric substrate (3), the third dielectric substrate (6), the fourth dielectric substrate (8), and the fifth dielectric substrate (10) are all hexagonal in shape.

9. A dual-polarized bandpass frequency selection unit with angle selectivity according to claim 1, characterized in that, The materials of the first metal layer (1), the second metal layer (4), the third metal layer (5), the fourth metal layer (7), and the fifth metal layer (9) all include: Copper (Cu), aluminum (Al), or gold (Au).

10. A microwave absorber, characterized in that, include: A periodically arranged, angle-selective, dual-polarized bandpass frequency selection unit as described in claims 1-9; wherein, and It is an integer greater than or equal to 1.

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