Dynamic regulation and control device for scattering amplitude loaded on edge of active frequency selective surface
By loading an active frequency-selective surface layer at the edge of a metal substrate and adjusting the resistance of a PIN diode, the problem of backscattering control under oblique incidence was solved, achieving lightweight and efficient backscattering intensity control that is adaptable to complex electromagnetic environments.
Patent Information
- Application Number
- CN202511689524.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-18
- Publication Date
- 2026-02-06
AI Technical Summary
Existing technologies cannot effectively control the backscattering cross section under oblique incidence, and traditional absorbing materials cannot achieve dynamic adaptation in complex electromagnetic environments.
An active frequency-selective surface layer is loaded at the edge of a metal substrate, and the resistance is adjusted by a PIN diode to achieve a continuous transition of impedance from free space to the metal substrate, thereby controlling the backscattering intensity.
It achieves dynamic control of the backscattering cross section of radar in a wide frequency band and wide angle domain, adapts to complex electromagnetic environments, and the device is lightweight and easy to apply on a large scale.
Smart Images
Figure CN121484480A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of functional absorbing materials technology, and more specifically, relates to a device for dynamic control of scattering amplitude by active frequency selective surface edge loading. Background Technology
[0002] With the increasing complexity of the electromagnetic environment, the dynamic transformation of scattering characteristics plays an increasingly important role in electronic warfare. Traditional absorbing materials have achieved relatively mature applications in radar stealth, but their performance is relatively fixed and lacks the ability to adapt to real-time changes in battlefield conditions. In recent years, active frequency selective surfaces (AFS), as a representative of structural electromagnetic materials, have received widespread attention. By loading tunable devices such as PIN diodes and varactor diodes onto periodic metal patterns, the impedance characteristics of the functional layer of the frequency selective surface can be dynamically adjusted, thereby controlling the response to incident electromagnetic waves. This characteristic makes it possible to dynamically change the target's scattering characteristics, achieving the purpose of appearing and disappearing intermittently for deception and camouflage.
[0003] Existing research indicates that when electromagnetic waves are incident directly onto a metal substrate, placing an active frequency-selective surface a quarter wavelength above the substrate and adjusting the resistance of the PIN diode loaded on it allows for varying degrees of impedance matching and absorption, thereby controlling the specular reflection intensity of the incident electromagnetic wave. Under a certain angle of oblique incidence, the specular (forward) scattering characteristics are still well maintained. However, current radar detection methods primarily rely on monostatic radar, meaning the detected echo signal direction is opposite to the incident electromagnetic wave signal direction (backward). Since backscattering sources under oblique incidence mainly originate from non-spectral reflection mechanisms such as edge scattering and surface traveling waves, traditional tunable absorption devices designed to control specular reflection characteristics fail because they cannot control backscattering characteristics. Systematic analysis and design work has not yet been conducted for dynamic control of edge scattering and backscattering amplitude control devices under oblique incidence. Since backscattering during electromagnetic wave propagation mainly originates from impedance mismatch between free space and the target, the impedance reconstruction characteristics of active frequency selective surfaces have a natural advantage in dynamically reconstructing the scattering characteristics of non-mirror scattering sources. Summary of the Invention
[0004] In view of the above-mentioned defects or improvement needs of the prior art, the present invention provides an active frequency selective surface edge loading dynamic control device for scattering amplitude, so as to solve the problem of backscattering cross section control under oblique incidence, and to flexibly adapt to the needs of complex and ever-changing electromagnetic environment.
[0005] To achieve the above objectives, the present invention provides an active frequency-selective surface edge-loaded dynamic scattering amplitude control device, which comprises, from bottom to top: a dielectric substrate layer and an adjustable functional layer; The adjustable functional layer includes a metal substrate and an active frequency selective surface layer disposed at the edge of the metal substrate; the active frequency selective surface layer is a periodically arranged array structure, each column includes multiple units connected in series, each unit includes the same metal pattern, and each is provided with a PIN diode.
[0006] Each column has the same length as the side length of the metal substrate. The column adjacent to the edge of the metal substrate is designated as the first column, and so on. The active frequency selective surface layer is divided into N columns (N≥1) from the metal substrate to the free space. PIN diodes loaded in the same column have the same resistance value, while PIN diodes in different columns may have the same or different resistance values. Without the active frequency selective surface layer loaded at the substrate edge, the characteristic impedance of the free space is 377Ω, and the impedance of the metal substrate is 0. Backscattering is excited at the edge of the metal substrate due to the impedance discontinuity (377→0). The impedance of the Nth column of the introduced active frequency selective surface layer is Z. FSS_N Its size is controlled by the resistance of the PIN diode loaded on it. An active frequency-selective surface layer introduced at the edge of the metal substrate acts as a bridge for the impedance transition from free space to the metal substrate (377→Z). FSS_N →…→Z FSS_1 →0), to achieve impedance continuity regulation. At the same time, the equivalent resistance of the PIN diode is used to realize energy loss, thereby effectively controlling the magnitude of backscattering intensity.
[0007] Preferably, the PIN diodes on different columns have the same resistance value, Z FSS_N =Z FSS_N-1 …=Z FSS_1 .
[0008] Preferably, the metal pattern types on the unit include: polygonal ring patterns, bow tie patterns, cross patterns, polygonal patterns, strip patterns, and square ring-strip composite patterns.
[0009] Preferably, the active frequency selection surface period is 5~40 mm.
[0010] Preferably, the width of the metal strips within the metal pattern is 0.1 to 5 mm, and the width of the gap between the metal strips is 0.1 to 1.5 mm.
[0011] Preferably, the PIN diode on the active frequency selective surface layer is equivalent to a parallel connection of a variable resistor Rv and a parasitic capacitance Cp=0.05 pF when it is turned on, and the resistance value of the adjustable resistor Rv is in the range of 5~400 Ω. When it is turned off, it is equivalent to a large resistor of 10000 Ω.
[0012] Preferably, the units in each column are connected by metal strips to power the PIN diodes.
[0013] Preferably, the dielectric substrate is made of glass fiber reinforced epoxy resin (FR4), polytetrafluoroethylene (F4B) or polyimide (PI) film with a thickness of 0.025~1 mm.
[0014] Preferably, the thickness of the metal pattern on the structure is 35μm to 100μm.
[0015] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: (1) This invention provides a dynamic control device for backscattering amplitude by loading an active frequency selective surface at the edge. The purpose is to introduce an active frequency selective surface layer at the edge of a metal substrate. This active frequency selective surface layer acts as a bridge between free space and the impedance transition of the metal substrate, thereby controlling the impedance continuity. Simultaneously, the equivalent resistance of the PIN diode is used to dissipate energy, thus effectively controlling the magnitude of the backscattering intensity. By controlling the impedance continuity at the edge truncation point, backscattering cross-section control in a wide frequency band and wide angle domain is achieved.
[0016] (2) The active frequency selective surface edge-loaded dynamic scattering amplitude control device provided by the present invention can have the same or different impedance (bias) states for each column. When the impedance magnitude of each column is the same, uniform impedance control (377→Z) can be achieved. FSS_N =Z FSS_N-1 …=Z FSS_1 →0), simple and efficient. When the impedance of each column is different, row-by-row impedance adjustment can be achieved. The impedance of each column can be transformed in an increasing or decreasing manner from the metal substrate to free space, or the impedance of each column can be randomly arranged and combined (377→Z). FSS_N →…→Z FSS_1 →0), offering a wide variety of options. Compared to traditional absorbing materials, it can flexibly adapt to the demands of complex and ever-changing electromagnetic environments. The active frequency selective surface features a flexible and simple unit pattern design, which is beneficial for large-scale applications.
[0017] (3) The active frequency selective surface edge loading dynamic control device for scattering amplitude provided by the present invention uses glass fiber reinforced epoxy resin (FR4), polytetrafluoroethylene (F4B) or polyimide (PI) film as the substrate. The film is very thin and the raw materials are all lightweight. The device provided by the present invention is a lightweight device and is suitable for carriers that require low added weight. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the active frequency selective surface edge loading scattering amplitude dynamic control device provided by the present invention.
[0019] Figure 2 This is a schematic diagram of the array arrangement and unit topology of the active frequency selective surface layer in the dynamic control device for scattering amplitude loading on the edge of the active frequency selective surface provided in Embodiment 1 of the present invention.
[0020] Figure 3 This describes the backscattering cross section amplitude control performance of Embodiment 1 of the present invention under different PIN resistance values.
[0021] Figure 4 This is a schematic diagram of the array arrangement and unit topology of the active frequency selective surface layer in the dynamic control device for scattering amplitude loading on the edge of the active frequency selective surface provided in Embodiment 2 of the present invention.
[0022] Figure 5 This is the radar cross-section amplitude control performance of Embodiment 2 of the present invention under different PIN resistance values.
[0023] Figure 6 This is a schematic diagram of the array arrangement and unit topology of the active frequency selective surface layer in the dynamic control device for scattering amplitude loading on the edge of the active frequency selective surface provided in Embodiment 3 of the present invention.
[0024] Figure 7 This is the radar cross-section amplitude control performance of Embodiment 3 of the present invention under different PIN resistance values.
[0025] Figure label: 1. Active frequency selective surface layer, 2. Metal substrate, 3. Dielectric substrate layer. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.
[0027] The present invention provides an active frequency selective surface edge loading scattering amplitude dynamic control device, which includes, from bottom to top: a dielectric substrate layer and an adjustable functional layer.
[0028] The adjustable functional layer includes a metal substrate and an active frequency selective surface layer disposed at the edge of the metal substrate; the metal substrate is a square all-metal plate. The active frequency selective surface layer is a periodically arranged array structure, each column including multiple units connected in series, each unit including the same metal pattern, and each unit is provided with a PIN diode. The length of each column is the same as the side length of the metal substrate, and the column adjacent to the edge of the metal substrate is designated as the first column, and so on. The active frequency selective surface layer is divided into N columns (N≥1) from the metal substrate to the free space; the PIN diodes loaded on the same column have the same resistance value, and the PIN diodes on different columns may have the same or different resistance values.
[0029] The impedance of the Nth column of the introduced active frequency-selective surface layer is Z. FSS_N Its size is controlled by the resistance of the PIN diode loaded on it. An active frequency-selective surface layer loaded at the edge of the metal substrate acts as a bridge for the impedance transition from free space to the metal substrate (377→Z). FSS_N →…→Z FSS_1 →0), to achieve impedance continuity regulation. At the same time, the equivalent resistance of the PIN diode is used to realize energy loss, thereby effectively controlling the magnitude of backscattering intensity.
[0030] The period of the unit structure is 5~40 mm. The width of the metal strips in the metal pattern within the unit structure is 0.1~5 mm, and the gap width between the metal strips is 0.1~1.5 mm. The PIN diode on the active frequency selective surface layer is equivalent to a parallel connection of a variable resistor Rv and a parasitic capacitance Cp=0.05 pF when in the on state. The adjustable resistor Rv has a resistance range of 5~400Ω, and is equivalent to a large resistor of 10000 Ω when in the off state. The units in each column are connected by metal strips to achieve the feeding of the PIN diodes.
[0031] In some alternative implementations, the upper dielectric substrate material is a glass fiber reinforced epoxy resin (FR4), polytetrafluoroethylene (F4B), or polyimide (PI) film with a thickness of 0.025~1 mm.
[0032] In some alternative implementations, the thickness of the metal pattern on the structure is 35 μm to 100 μm.
[0033] To further illustrate the active frequency-selective surface edge-loaded dynamic scattering amplitude control device provided by the present invention, the following detailed description is provided in conjunction with embodiments.
[0034] Example 1 An active frequency-selective surface edge-loaded dynamic scattering amplitude control device, such as... Figure 1 As shown. From bottom to top, it includes: a dielectric substrate layer and a tunable functional layer.
[0035] The metal substrate is a square all-metal plate. The adjustable functional layer consists of the metal substrate and active frequency selective surface layers arranged parallel to the four edges of the metal substrate. The active frequency selective surface layers are periodic array structures arranged in rows and columns, and each unit structure includes the same metal pattern and is equipped with PIN diodes.
[0036] The metal substrate measures 500*500 mm. The dielectric substrate is made of glass fiber reinforced epoxy resin with a relative permittivity of 4.4 and a thickness of 0.15 mm.
[0037] The active frequency selective surface layer has dimensions of 500 mm * 60 mm, N=6, and contains 50 * 6 cells (50 rows * 6 columns). The array arrangement and cell topology of the active frequency selective surface layer are as follows. Figure 2 As shown. The unit period is 10 mm, and the metal pattern on the unit is a patch strip with a line width of 0.5 mm. It is broken into 3 spaced sub-parts with a gap width of 1 mm, and a PIN diode is placed in the gap.
[0038] The PIN diode is equivalent to a parallel connection of an adjustable resistor Rv and a parasitic capacitance Cp=0.05pF when it is turned on. The adjustable range of Rv is 5~400 Ω. The equivalent resistance value is 10000 Ω when it is turned off. The resistance value of each PIN diode is the same.
[0039] The model was modeled and simulated in the electromagnetic simulation software CST. The frequency sweep performance under TE polarization at 45° oblique incidence is as follows: Figure 3 As shown, due to the effective control of edge scattering at the truncation point, the proposed dynamic scattering amplitude control device can achieve a backscattering cross-section amplitude control effect of 10~15 dB within 1~3 GHz.
[0040] Example 2 In this embodiment, the dynamic control device for scattering amplitude loaded on the active frequency selective surface is the same as in Embodiment 1. N=6, and the metal pattern of the unit adopts a composite type of metal square ring and metal strip.
[0041] The metal substrate has dimensions of 500*500 mm. The dielectric substrate layer has the same material and dimensions as in Example 1. The active frequency selective surface layer has dimensions of 500 mm*60 mm and contains 50*6 periodic units. The unit arrangement array is as follows: Figure 4As shown, the line width is 0.5 mm, the outer ring width is 6 mm, and the inner ring width is 5 mm. The ring has two openings with a 1 mm gap, and a PIN diode is placed within the gap. The PIN diode has an adjustable resistance range of 5~400 Ω in the on state and an equivalent resistance of 10000 Ω in the off state. Different equivalent resistance values of the diodes can achieve different degrees of impedance transition effects, thus achieving the purpose of controlling the edge scattering level.
[0042] The model was modeled and simulated in the electromagnetic simulation software CST. The frequency sweep performance under TE polarization at 45° oblique incidence is as follows: Figure 5 As shown, a radar cross section amplitude modulation effect similar to that of Example 1 is obtained. Due to the effective control of scattering at the edge, the proposed active frequency selective surface edge-loaded dynamic scattering amplitude modulation device can achieve a backscattering cross section amplitude modulation effect of 10~15 dB within 1~3 GHz.
[0043] Example 3 In this embodiment, the dynamic control device for scattering amplitude loaded on the active frequency selective surface edge is the same as in Embodiment 1. N=6, and the metal pattern of the unit adopts a bowtie shape.
[0044] The metal substrate has dimensions of 500*500 mm. The dielectric substrate layer has the same material and dimensions as in Example 1. The active frequency selective surface layer has dimensions of 500 mm*60 mm and contains 50*6 periodic units. The unit arrangement array is as follows: Figure 4 As shown, the bow tie has an opening at its center with a gap of 1 mm, and a PIN diode is placed within the gap. The PIN diode has an adjustable range of 5~400 Ω in the on state and an equivalent resistance of 10000 Ω in the off state. Different equivalent resistance values of the diode can achieve different degrees of impedance transition effects, thereby achieving the purpose of controlling the edge scattering level.
[0045] The model was modeled and simulated in the electromagnetic simulation software CST. The simulation performance under TE polarization at 45° oblique incidence is as follows: Figure 7 As shown, by loading an active frequency-selective surface layer at the edge of the metal substrate and controlling the resistance value of the PIN diode, a backscattering cross-section amplitude modulation effect of 10~15 dB can be achieved within 1~3 GHz.
[0046] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A device for dynamically controlling the scattering amplitude of an active frequency-selective surface edge-loaded surface, characterized in that, From bottom to top, this includes: Dielectric substrate layer and tunable functional layer; The adjustable functional layer includes a metal substrate and an active frequency selective surface layer disposed on the edge of the metal substrate. The active frequency selective surface layer is a periodically arranged array structure, each column including multiple units connected in series, each unit including the same metal pattern and each having a PIN diode. The length of each column is the same as the side length of the metal substrate. The column adjacent to the edge of the metal substrate is designated as the first column. The active frequency selective surface layer is divided into N columns from the metal substrate to the free space, where N≥1. The PIN diodes loaded on the same column have the same resistance value, and the PIN diodes on different columns may have the same or different resistance values.
2. The scattering amplitude dynamic control device according to claim 1, characterized in that, The The metal pattern types of the unit include: polygonal ring pattern, bow tie shape, cross shape, polygonal pattern, strip pattern, and square ring-strip composite pattern.
3. The scattering amplitude dynamic control device according to claim 2, characterized in that, The period of the unit is 5~40mm.
4. The scattering amplitude dynamic control device according to claim 2, characterized in that, The width of the metal strips within the metal pattern is 0.1~5 mm, and the width of the gaps between the metal strips is 0.1~1.5 mm.
5. The scattering amplitude dynamic control device according to claim 1, characterized in that, When the PIN diode is turned on, it is equivalent to a parallel connection of a variable resistor Rv and a parasitic capacitance Cp. The adjustable resistor Rv has a resistance range of 5~400 Ω. When the PIN diode is turned off, it is equivalent to a resistor of 10000 Ω.
6. The scattering amplitude dynamic control device according to claim 1, characterized in that, The dielectric substrate is made of glass fiber reinforced epoxy resin FR4, polytetrafluoroethylene F4B, or polyimide PI film, with a thickness of 0.025~1 mm.
7. The scattering amplitude dynamic control device according to claim 1, characterized in that, The thickness of the metal pattern is 35μm to 100μm.