CN117276911A

CN117276911A - Broadband lumped resistance FSS wave absorber

Info

Publication number: CN117276911A
Application number: CN202311330301.6A
Authority: CN
Inventors: 王东俊; 张袁; 陈希翔; 高鹏; 张喜; 唐志; 肖菊飞
Original assignee: Chengdu Aircraft Industrial Group Co Ltd
Current assignee: Chengdu Aircraft Industrial Group Co Ltd
Priority date: 2023-10-16
Filing date: 2023-10-16
Publication date: 2023-12-22

Abstract

The invention relates to the technical field of electromagnetic wave absorption, in particular to a broadband lumped resistance FSS wave absorber, which comprises a medium matching layer, a first air spacing layer, a lumped resistance FSS loss layer, a medium substrate layer, a second air spacing layer and a metal reflecting plate which are connected in sequence; wherein the lumped resistance FSS loss layer comprises four cross-connected metal FSS structures; the metal FSS structure comprises a round metal structure arranged at one end and a strip-shaped metal structure arranged at the other end; and all be provided with the clearance on four bar metal structures and be used for welding lumped resistance, only set up one deck loss layer and every layer only sets up 4 lumped resistance, simple structure and have better superiority in bandwidth and angular stability.

Description

Broadband lumped resistance FSS wave absorber

Technical Field

The invention relates to the technical field of electromagnetic wave absorption, in particular to a broadband lumped resistance FSS wave absorber.

Background

With the rapid development of 5G/6G wireless technology, great demands are put on electromagnetic wave absorbing materials. The ideal wave absorbing structure has the characteristics of full-band coverage, full-angle coverage and light weight, but the requirements are difficult to meet in practical engineering application. Therefore, the wave-absorbing structure generally takes broadband, high angular stability and thinness as main indexes, but achieving the three indexes simultaneously is very difficult. The Rozanov study indicates that there is a theoretical limit thickness for the non-magnetic material absorber at a given frequency band, i.e., the Rozanov limit thickness. This means that the minimum thickness of the wave absorber is not lower than this limit thickness for a given frequency band and wave absorption. Therefore, the design of the wave absorber does not need to perfectly realize a certain performance, but comprehensively balances the bandwidth, the angular stability and the thickness of the wave absorbing structure according to the practical engineering application requirements.

Common electromagnetic wave absorbing materials include dielectric loss based wave absorbing materials, magnetic dielectric loss based wave absorbing materials and circuit analog wave absorbers. The wave-absorbing material based on magnetic medium loss can effectively reduce the whole thickness due to high magnetic permeability, but most of the materials are hydroxyl iron, so that the wave-absorbing material is heavy. In the circuit simulation wave absorber, compared with the traditional Salisbury screen and Jaumann screen, the frequency selection surface wave absorber has wide working frequency band and relatively thin thickness, and has been widely applied to the fields of antennas, radomes, stealth structures, electromagnetic interference suppression and the like.

The frequency selective surface (Frequency selective surface, FSS) is an artificial electromagnetic periodic structure that reflects, transmits or absorbs incident electromagnetic waves depending on the cell structure. The frequency selective surface wave absorber is divided into a resistor film FSS wave absorber and a total resistor FSS wave absorber. The problems that the square resistance precision and uniformity are poor are difficult to control in the manufacturing process of the resistance film FSS, so that the difference exists between the performance of the processed FSS wave absorber and the design simulation result, the structural design of the FSS wave absorber needs to be fully considered in the simulation design period, and the influence of square resistance disturbance on the wave absorbing performance in the processing process is prevented. The lumped resistance FSS absorber adopts a printed circuit board (Printed Circuit Board, PCB) technology to prepare a metal FSS unit structure, and a patch resistor with a certain resistance is welded on a preferred position of the metal FSS structure, so that each design parameter can be accurately controlled, and electromagnetic waves irradiated on the FSS absorber structure are effectively absorbed. The broadband FSS absorber can be combined with a band-pass FSS structure to be used in electromagnetic wave absorption and transmission integrated structural design. Compared with a resistance film FSS absorber, the lumped resistance FSS loss layer is easier to reduce insertion loss in a passband, so that the method has wider application fields.

When electromagnetic waves are irradiated to the lumped resistance FSS absorber, a current is induced in the FSS layer, and a loss is generated by flowing through the lumped resistance. Therefore, for a wideband FSS absorber, it is desirable that the induced current be generated across the entire bandwidth on the FSS structure and that the maximum current flow through the lumped resistance. The adoption of multiple resistors (such as 8 or even 16 resistors in each unit) distributed at different positions of the same-layer FSS unit structure or the multi-layer FSS structure can certainly reduce the design difficulty of the broadband lumped resistance FSS absorber. This is just a method commonly adopted in the current technology, for example, the application number is "202210009079.9", the patent name is "a chinese invention patent of ultra wideband wave absorbing structure for antenna RCS reduction", the consumed FSS of the wave absorber adopts a bimetal ring loaded with 8 lumped resistors, so that the structure realizes wideband absorption, but the angular stability of the structure is only 30 °, and the thickness is not advantageous. The patent application number is 202110649689.0, the patent name is Chinese patent invention of an ultra-wideband absorber with a symmetrical G-type bending structure, lumped resistors FSS are respectively printed on the upper surface and the lower surface of an FR-4 medium substrate, the upper surface FSS is a complex G-type bending metal wire loaded with four resistors, the lower surface is a metal square ring loaded with eight resistors, and the broadband effect is realized by utilizing multilayer FSS loss hierarchy, but the FSS layer structure is complex and the unit resistance number is more. To suppress grating lobes and improve the electromagnetic wave incidence angle stability, the FSS cell period is typically less than one half wavelength. The miniaturization period can also meet the requirement of enough period numbers arranged on a limited area in engineering practical application so as to ensure that the FSS structure performance is not changed. However, in the unit area with limited size, the more complex the FSS unit structure is, the more chip resistors are welded on the FSS unit structure, the smaller the adjacent metal structures and resistor intervals are, which not only requires higher processing precision, but also improves the processing and later operation and maintenance costs.

Disclosure of Invention

Aiming at the problem that the bandwidth, the angle stability and the thickness of the wave-absorbing structure cannot be balanced at the same time in the conventional battery wave-absorbing structure, the invention provides a broadband lumped resistance FSS wave absorber, which comprises a medium matching layer, a first air spacing layer, a lumped resistance FSS loss layer, a medium substrate layer, a second air spacing layer and a metal reflecting plate which are connected in sequence; wherein the lumped resistance FSS loss layer comprises four cross-connected metal FSS structures; the metal FSS structure comprises a round metal structure arranged at one end and a strip-shaped metal structure arranged at the other end; and all be provided with the clearance on four bar metal structures and be used for welding lumped resistance, only set up one deck loss layer and every layer only sets up 4 lumped resistance, simple structure and have better superiority in bandwidth and angular stability.

The invention has the following specific implementation contents:

a broadband lumped resistance FSS absorber comprises a plurality of cube structure layers; the cube structure layers comprise a medium matching layer, a first air spacing layer, a lumped resistance FSS loss layer, a medium substrate layer, a second air spacing layer and a metal reflecting plate which are sequentially connected from top to bottom;

the lumped resistance FSS loss layer comprises four cross-connected metal FSS structures;

the metal FSS structure comprises a round metal structure arranged at one end and a strip-shaped metal structure arranged at the other end;

gaps are formed on the four strip-shaped metal structures, and one ends of the four strip-shaped metal structures, which are not connected with the round metal structures, are mutually perpendicular;

the gap is used to solder the lumped resistance.

In order to better realize the invention, the broadband lumped resistance FSS absorber further comprises a square ring resistance film; the square ring resistive film is disposed between the dielectric matching layer and the first air spacer layer.

In order to better realize the invention, further, the dielectric materials of the dielectric matching layer and the dielectric substrate layer are FR-4 dielectric materials, polytetrafluoroethylene, F4B plates or Rogowski plates.

To better practice the invention, further, the first air spacer layer and the second air spacer layer are polymethacrylimide foam with a dielectric constant of 1.06 or other foam materials with a dielectric constant similar to that of air.

In order to better realize the invention, further, the circular metal structure is a metal circular ring structure or a metal open hole ring structure.

In order to better realize the invention, the lumped resistor is a high-frequency chip resistor.

In order to better implement the invention, further, the radius r of the circular metal structure is 0.9mm.

To better implement the invention, further, the width w of the strip-shaped metal structure is 0.5mm.

In order to better implement the invention, further, the length s of the gap is 0.5mm.

The invention has the following beneficial effects:

(1) The wave absorber provided by the invention has a simple structure and a small number of lumped resistors; the electromagnetic wave absorption rate of 90% of the C wave band to the K wave band is realized, the polarization mode of the incident wave is insensitive, and the incident angle stability reaches 45 degrees. The wave absorbing structure only uses one FSS loss layer, each unit only uses 4 resistors, and compared with the existing wave absorbing body with 4 lumped resistors or even a plurality of resistors loaded on each unit, the wave absorbing structure has more superiority in bandwidth and angle stability.

(2) According to the invention, the metal FSS structure is arranged to be a symmetrical structure, so that the polarization stability of the incident electromagnetic wave is improved.

(3) Compared with the prior structure, the FSS structure obtained by arranging the square ring resistor film at the bottom of the medium matching layer has the 80% wave absorption bandwidth of 130.9% from 4.8-23.0GHz relative bandwidth; the relative bandwidth is improved to be 139.6% of the relative bandwidth of 4.5-25.3 GHz.

Drawings

Fig. 1 is a schematic diagram of the overall structure of the broadband lumped resistance FSS absorber provided by the present invention.

Fig. 2 is a schematic structural diagram of a lumped resistance FSS loss layer according to the present invention.

Fig. 3 is a schematic diagram of reflection coefficient curves of the broadband lumped resistance FSS absorber provided by the present invention under the perpendicular incidence condition in two electromagnetic wave polarization modes of TE and TM.

Fig. 4 is a schematic diagram of absorption curves of the broadband lumped resistance FSS absorber provided by the present invention under the perpendicular incidence condition in two electromagnetic wave polarization modes of TE and TM.

Fig. 5 is a schematic diagram of reflection coefficient curves of the broadband lumped resistance FSS absorber provided by the present invention under TE polarization at different incident angles.

Fig. 6 is a schematic diagram of absorption curves of the broadband lumped resistance FSS absorber provided by the present invention under TE polarization at different incident angles.

Fig. 7 is a schematic diagram of reflection coefficient curves of the broadband lumped resistance FSS absorber provided by the present invention under TM polarization at different incident angles.

Fig. 8 is a schematic diagram of absorption curves of the broadband lumped resistance FSS absorber provided by the present invention under TM polarization at different angles of incidence.

Fig. 9 is a schematic view of the FSS absorber structure obtained by providing a square ring resistive film.

Fig. 10 is a schematic diagram showing the comparison of the absorption curve of the structure with the square-ring resistive film and the absorption curve of the original wave-absorbing structure without the square-ring resistive film.

FIG. 11 is a schematic view of the FSS absorber structure with the dielectric matching layer and the first air spacer layer removed.

Fig. 12 is a schematic diagram showing the comparison between the absorption curve of the structure shown in fig. 11 and the absorption curve of the present invention when electromagnetic waves are perpendicularly incident.

Fig. 13 is a schematic diagram showing the comparison between the absorption curve of the structure shown in fig. 11 and the absorption curve of the present invention when the electromagnetic wave is obliquely incident at 45 °.

Fig. 14 is a schematic structural view of a metal circular structure as a metal ring structure.

Fig. 15 is a schematic structural view of a metal circular structure as a metal open-cell ring structure.

The device comprises a dielectric matching layer 1, a dielectric matching layer 2, a first air spacing layer, a lumped resistance FSS loss layer 3, a dielectric substrate layer 4, a second air spacing layer 5, a metal reflecting plate 6, a lumped resistance layer 7, a circular metal structure 8, a circular metal structure 9, a strip-shaped metal structure 10 and a square ring resistance film.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it should be understood that the described embodiments are only some embodiments of the present invention, but not all embodiments, and therefore should not be considered as limiting the scope of protection. All other embodiments, which are obtained by a worker of ordinary skill in the art without creative efforts, are within the protection scope of the present invention based on the embodiments of the present invention.

In the description of the present invention, it should be noted that, unless explicitly stated and limited otherwise, the terms "disposed," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; or may be directly connected, or may be indirectly connected through an intermediate medium, or may be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

Example 1:

the embodiment provides a broadband lumped resistance FSS absorber, which is shown in figure 1 and comprises a plurality of cube structure layers; the cube structure layers comprise a medium matching layer 1, a first air spacing layer 2, a lumped resistance FSS loss layer 3, a medium substrate layer 4, a second air spacing layer 5 and a metal reflecting plate 6 which are sequentially connected from top to bottom;

the lumped resistance FSS loss layer 3 comprises four cross-connected metal FSS structures;

the metal FSS structure comprises a round metal structure 8 arranged at one end and a strip-shaped metal structure 9 arranged at the other end;

gaps are formed on the four strip-shaped metal structures 9, and one ends of the four strip-shaped metal structures 9, which are not connected with the round metal structures 8, are mutually perpendicular;

the gap is used to solder the lumped resistance 7.

Working principle: the wave absorber structure provided by the embodiment comprises a medium matching layer 1, a first air spacing layer 2, a lumped resistance FSS loss layer 3, a medium substrate layer 4, a second air spacing layer 5 and a metal reflecting plate 6 which are connected in sequence; wherein the lumped resistance FSS loss layer 3 comprises four cross-connected metallic FSS structures; the metal FSS structure comprises a round metal structure 8 arranged at one end and a strip-shaped metal structure 9 arranged at the other end; gaps are formed in the four strip-shaped metal structures 9 and used for welding the lumped resistors 7, only one layer of lumped resistor FSS loss layer 3 is arranged, and only 4 lumped resistors 7 are arranged in each layer, so that the novel high-voltage-source-type semiconductor laser has a simple structure and better superiority in bandwidth and angle stability.

Example 2:

this embodiment will be described in detail with reference to one specific example on the basis of embodiment 1.

The embodiment aims to design a frequency selective surface wave-absorbing structure with simpler FSS structure and less lumped resistance, realize 90% electromagnetic wave-absorbing rate from C wave band to K wave band, and is insensitive to the polarization mode of incident waves, and the stability of the incident angle reaches 45 degrees. The wave absorbing structure only uses one FSS loss layer, each unit only uses 4 patch resistors, and compared with the existing wave absorbing body with 4 lumped resistors 7 or even a plurality of resistors loaded on each unit, the wave absorbing structure has more superiority in bandwidth and angle stability.

The embodiment comprises a plurality of square structural layers which are sequentially stacked, wherein each structural layer is in a central symmetrical pattern, and the structural layers sequentially comprise a medium matching layer 1, a first air spacing layer 2, a lumped resistance FSS loss layer 3, a medium substrate layer 4, a second air spacing layer 5 and a metal reflecting plate 6 from top to bottom. The FSS wave absorbing structure is a central symmetrical structure and can show good polarization stability for incident electromagnetic waves.

The dielectric matching layer 1 is used for enhancing the impedance matching of the wave absorbing structure and the free space on the one hand so as to improve the bandwidth and the angle stability. On the other hand, the dielectric matching layer 1 protects the lumped resistance FSS loss layer 3 from the external environment, avoiding the resulting performance degradation. The medium matching layer 1 can use FR-4 medium materials commonly used in the market, and can also use other medium plates such as polytetrafluoroethylene, F4B plates, rojies plates and the like.

Other FSS loss layers can be loaded on the medium matching layer 1, and the bandwidth of the wave-absorbing structure is further widened or the absorption performance is improved under the condition that the overall thickness is unchanged. For example, fig. 9 shows an FSS structure obtained by loading a square ring resistive film 10 on the bottom of the dielectric matching layer in this embodiment, and fig. 10 shows a comparison between the absorption curve of the structure and the absorption curve of the present invention, compared with the original structure, the 80% absorption bandwidth is increased from 4.8-23.0GHz to 130.9% and from 4.5-25.3GHz to 139.6%.

The first air spacing layer 2 is combined with the medium matching layer 1, so that impedance matching can be realized between the wave absorber and the free space in a wider frequency range, and the absorption bandwidth is widened. Meanwhile, as the patch resistor on the lumped resistance FSS loss layer 3 has a certain thickness, the first air spacing layer 2 separates the lumped resistance FSS loss layer 3 from the medium matching layer 1, and unstable wave absorbing performance caused by an air gap due to resistance when the medium matching layer 1 is directly contacted with the lumped resistance FSS loss layer 3 is avoided. The first air spacer layer 2 may be replaced by a Polymethacrylimide (PMI) foam having a dielectric constant of about 1.06 or other plastic foam having a near dielectric constant.

As shown in fig. 2, the lumped resistance FSS dissipation layer 3 is a periodic square structure, the FSS unit structure is a mutually orthogonal dumbbell-shaped metal structure, and as shown in fig. 14 and 15, the terminal metal circular structure can be replaced by a metal circular ring structure, or a metal open-pore ring structure, or other ring-shaped or patch-shaped structures, so as to meet the requirements of different working frequency bands. 4 voids were left in place near the center of the cell to solder 4 chip resistors. The metal round structure at the tail end of the metal belt is used for providing reactance, and can stabilize the input impedance of the intermediate frequency band wave-absorbing structure, so that an absorption peak is introduced, and the whole structure has a better absorption effect on the intermediate and low frequency electromagnetic waves. The lumped resistance is loaded at the position with the strongest FSS current distribution and absorbs electromagnetic waves in an ohmic loss mode.

The mutually orthogonal dumbbell-shaped FSS metal structure is made of copper or other metal materials, and is prepared on the dielectric substrate layer through PCB technology. The lumped resistor 7 loaded in the FSS is a high-frequency chip resistor, and is welded on a designated position of the metal FSS structure through a surface mounting technology (Surface Mounted Technology, SMT) or manually.

The dielectric substrate layer is made of the same or different dielectric substrate materials as the dielectric matching layer, and comprises dielectric plates such as FR-4 material, F4B plate, rogowski plate and the like, and a metal FSS structure in the FSS loss layer is printed on the dielectric substrate.

The second air spacer layer 5 is used to space the lumped resistance FSS loss layer 3, which provides proper electromagnetic wave phase compensation such that the lumped resistance FSS loss layer 3 is located at or near the electric field maximum of the electromagnetic wave, resulting in electromagnetic losses. The thicknesses of the first air spacing layer 2 and the second air spacing layer 5 are reasonably adjusted, and the input impedance of the whole FSS wave absorbing structure can be effectively controlled, so that the wave absorber can realize wider absorption bandwidth. The second air spacer layer 5 may be replaced by a polymethacrylimide foam PMI foam having a dielectric constant of about 1.06 or other plastic foam having a near dielectric constant.

The metal reflecting plate 6 is made of good conductor metal materials such as copper, aluminum, gold, silver and the like which are arranged on the back surface of the second air spacing layer 5, and the metal reflecting plate 6 is used for reflecting electromagnetic waves, preventing the electromagnetic waves from entering the back of the wave absorbing material and ensuring that the reflected electromagnetic waves are absorbed by the FSS lossy layer.

The embodiment provides the lumped resistance FSS absorber with a simple structure, which can be used for reducing the radar scattering cross section and improving the stealth performance; or used in the field of electromagnetic shielding to suppress electromagnetic interference. Particularly, for a closed space with dense electronic equipment, such as a cabin, a ship cabin, a vehicle and the like, after the interference electromagnetic wave is reflected, a reverberation effect or a resonance effect is easily generated, and the FSS absorber of the embodiment can be attached to an electronic equipment shell or a cavity wall of the closed space for absorbing the space interference electromagnetic wave to realize electromagnetic shielding of the electronic equipment.

Other portions of this embodiment are the same as those of embodiment 1 described above, and thus will not be described again.

Example 3:

in this embodiment, the effect of the broadband lumped resistance FSS absorber is described in terms of absorption and reflectance curves as shown in fig. 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and 13 on the basis of any one of embodiments 1 to 2.

Fig. 3 is a schematic diagram showing the reflection coefficient curves of the broadband lumped resistance FSS absorber under the polarization modes of the TE and TM electromagnetic waves under the condition of normal incidence. Therefore, the reflection coefficient of the wave absorber in the frequency range of 5.2GHz-22.2GHz is smaller than-10 dB, and the relative bandwidth is 124%. And the reflection coefficients of the wave absorber in TE and TM polarization are completely overlapped, which shows that the wave absorber has good polarization stability.

Fig. 4 is a schematic diagram showing absorption curves of the broadband lumped resistance FSS absorber under the polarization modes of TE and TM electromagnetic waves under the condition of normal incidence. Therefore, the absorption rate of the wave absorber is more than 90% in the frequency range of 5.2GHz-22.2GHz, and the wave absorber has good polarization stability.

Fig. 5 is a schematic diagram showing the reflection coefficient curves of the broadband lumped resistance FSS absorber under TE polarization at different incident angles. It can be seen that the reflection coefficient of the absorber gradually increases with increasing incidence angle under TE polarization. When electromagnetic waves are obliquely incident to the surface of the wave absorber at 55 degrees, the wave absorber can still meet the condition that the reflection coefficient is smaller than-10 dB in the frequency range of 6.1GHz-22 GHz.

Fig. 6 is a schematic diagram showing absorption curves of the broadband lumped resistance FSS absorber under TE polarization at different incident angles. It is known that the absorption rate of the absorber gradually decreases with increasing incidence angle under TE polarization. And when the electromagnetic wave is obliquely incident at 55 degrees, the absorption rate of the wave absorber can still be more than 90% in the frequency range of 6.1GHz-22GHz, which shows that the wave absorber can meet the angular stability of 55 degrees under TE polarization.

Fig. 7 is a schematic diagram showing the reflection coefficient curves of the broadband lumped resistance FSS absorber under TM polarization at different incident angles. From this, it can be seen that the reflection coefficient curve of the absorber gradually shifts to a high frequency with an increase in the incident angle under TM polarization. When electromagnetic waves are obliquely incident to the surface of the wave absorber at 45 degrees, the wave absorber can still meet the condition that the reflection coefficient is smaller than-10 dB in the frequency range of 7.8GHz-24 GHz.

Fig. 8 is a schematic diagram showing absorption curves of the broadband lumped resistance FSS absorber under TM polarization at different incident angles. Therefore, under TM polarization, when electromagnetic waves are obliquely incident to the surface of the wave absorber at 45 degrees, the wave absorber can still meet the requirement that the absorptivity is more than 90% in the frequency range of 7.8GHz-24GHz, which indicates that the wave absorber can meet the angular stability of 45 degrees under TM polarization.

As shown in fig. 9, the FSS absorber structure is obtained by loading a resistive film square ring FSS layer on the bottom of the dielectric matching layer 1. I.e. adding a resistive film FSS depletion layer without changing the thickness.

Fig. 10 is a schematic diagram showing the absorption curve of the structure shown in fig. 9 compared with the absorption curve of the original absorbing structure, i.e. the absorption curve of the FSS loss layer 3 with only one lumped resistance. As can be seen from FIG. 10, after the resistor film square ring FSS is loaded, the 90% wave absorption bandwidth is increased from 5.2GHz-22.2GHz with a relative bandwidth of 124% to 4.88GHz-26.9GHz with a relative bandwidth of 138.4% under the condition of normal incidence without changing the thickness of the wave absorber, although the wave absorption rate is slightly reduced in the frequency band of 5.2GHz-22.2 GHz.

The FSS absorber structure is shown in fig. 11, in which the dielectric matching layer 1 and the first air spacer layer 2 are removed, and the thickness of the second air spacer layer 5 is adjusted.

Fig. 12 shows a comparison of the absorption curves of the structures shown in fig. 11 when electromagnetic waves are perpendicularly incident. As can be seen from FIG. 12, after the medium matching layer is added, the 1, 90% wave absorption bandwidth is increased from 6.9GHz to 19.2GHz, the relative bandwidth is 94.3%, and the relative bandwidth is increased to 5.2GHz to 22.2GHz, and the relative bandwidth is 124%.

Fig. 13 shows a comparison of the absorption curves of the structure shown in fig. 11 when electromagnetic waves are obliquely incident at 45 °. As can be seen from fig. 13, the addition of the dielectric matching layer 1 can effectively improve the angular stability of the structure and reduce the frequency shift.

Table 1 shows a table of parameter correspondence of the broadband lumped resistance FSS absorber set in this embodiment.

Table 1 wave-absorbing structure parameter correspondence table

The absorption frequency band and the absorption rate can be adjusted by modifying the values of these parameters in table 1.

Other portions of this embodiment are the same as any of embodiments 1 to 2, and thus will not be described again.

The foregoing description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent variation, etc. of the above embodiment according to the technical matter of the present invention fall within the scope of the present invention.

Claims

1. The broadband lumped resistance FSS absorber is characterized by comprising a plurality of cube structure layers; the cube structure layers comprise a medium matching layer (1), a first air spacing layer (2), a lumped resistance FSS loss layer (3), a medium substrate layer (4), a second air spacing layer (5) and a metal reflecting plate (6) which are sequentially connected from top to bottom;

the lumped resistance FSS loss layer (3) comprises four cross-connected metal FSS structures;

the metal FSS structure comprises a round metal structure (8) arranged at one end and a strip-shaped metal structure (9) arranged at the other end;

gaps are formed on the four strip-shaped metal structures (9), and one ends, which are not connected with the round metal structures (8), of the four strip-shaped metal structures (9) are mutually perpendicular;

the gap is used for welding lumped resistances (7).

2. A broadband lumped resistance FSS absorber as claimed in claim 1 further comprising a square loop resistive film (10); the square ring resistor film (10) is arranged between the medium matching layer (1) and the first air spacing layer (2).

3. A broadband lumped resistance FSS absorber according to claim 1, characterized in that the dielectric material of the dielectric matching layer (1) and the dielectric substrate layer (4) is FR-4 dielectric material, polytetrafluoroethylene, F4B board or rogers board.

4. A broadband lumped resistance FSS absorber according to claim 1, wherein said first air spacer layer (2) and said second air spacer layer (5) are foam materials having a dielectric constant close to that of air.

5. A broadband lumped resistance FSS absorber as claimed in claim 1 wherein said circular metal structure (8) is a metal annular structure or a metal open-cell annular structure.

6. A broadband lumped resistance FSS absorber according to claim 1, characterized in that the lumped resistance (7) is a high frequency chip resistor.

7. A broadband lumped resistance FSS absorber according to claim 1, characterized in that the radius r of the circular metal structure (8) is 0.9mm.

8. A broadband lumped resistance FSS absorber according to claim 1, characterized in that the width w of the strip-shaped metal structures (9) is 0.5mm.

9. A broadband lumped resistance FSS absorber as recited in claim 1 wherein the gap has a length s of 0.5mm.