Electromagnetic protection method and device based on random phase

Abstract

The application relates to the technical field of electromagnetic protection, and provides an electromagnetic protection method and device based on random phases. The application constructs a wide-range random reflection phase distribution, so that the high-power electromagnetic energy signals are uniformly dispersed in all directions in space in a protection state, the electromagnetic energy entering a feed source is significantly reduced, and efficient and stable electromagnetic protection is realized. Through the establishment of a parameterized curved surface model and the mapping and integration of reflection-type ESS units to corresponding positions of the parameterized curved surface model, the curved surface parameterization modeling and unit mapping method is used to realize the high-precision and high-efficiency integration of the reflection-type ESS units on any complex curved surface.

Description

Technical Field

[0001] This application relates to the field of electromagnetic protection technology, and in particular to an electromagnetic protection method and device based on random phase. Background Technology

[0002] As a front-door coupling channel, the antenna is susceptible to high-power electromagnetic signals. These signals can couple into the receiver front end through the antenna, causing performance degradation or even permanent damage to sensitive components such as low-noise amplifiers.

[0003] Among existing electromagnetic protection methods, Energy Selective Surfaces (ESS) achieve adaptive switching of field-induced impedance through nonlinear devices, enabling low insertion loss transmission under normal signal conditions and exhibiting high shielding under high-power electromagnetic signals. However, existing research mainly focuses on planar configurations, which are difficult to conformally integrate with large-size curved radomes or reflectors, and suffer from electromagnetic distribution distortion and performance degradation in curved states.

[0004] For reflector antennas, existing research has attempted to achieve "weak field focusing and strong field defocusing" by loading reflective ESS elements to change the phase distribution of the reflector under high-power electromagnetic environments. However, in existing methods, the adjustment of the reflection phase under protective conditions is relatively simple, making it difficult to achieve a continuously adjustable random phase distribution over a wide phase range, thus limiting the protection effectiveness. On the other hand, the lack of systematic surface parametric modeling and element mapping methods makes it difficult to efficiently achieve high-precision integration of reflective ESS elements on complex curved reflector surfaces. Summary of the Invention

[0005] Therefore, it is necessary to provide an electromagnetic protection method and device based on random phase to address the aforementioned technical problems.

[0006] An electromagnetic protection method based on random phase, the method comprising the following steps: Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, and based on Huygens' principle, a reflective ESS element array is constructed, consisting of reflective ESS elements arranged in a fixed period size. The reflective ESS element includes an I-shaped metal patch, an air dielectric layer, and a metal backplate arranged from top to bottom. The longitudinal arm of the I-shaped metal patch has a gap, and a PIN diode is loaded in the gap to evenly divide the I-shaped metal patch. The reflection phase of each reflective ESS element under protection is constructed using a wide-range random phase distribution method; Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, a parameterized surface model is established. The phase-reconfigurable reflective ESS elements are mapped one by one and integrated into the corresponding positions of the parameterized surface model to generate a surface electromagnetic protection structure model.

[0007] In one embodiment, the length of the horizontal strip of the I-shaped metal patch is adjustable.

[0008] In one embodiment, the reflection phase of each reflective ESS element in the protected state is constructed using a wide-range random phase distribution method, including: Within a wide phase range, the reflection phase of each reflective ESS cell is randomly generated, and the reflection phases of all reflective ESS cells are independent of each other and follow a uniform random distribution.

[0009] In one embodiment, based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, a parameterized surface model is established. Phase-reconfigurable reflective ESS elements are mapped and integrated one by one into the corresponding positions of the parameterized surface model to generate a surface electromagnetic protection structure model, including: Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, a parameterized surface equation is established. The grid is divided according to the period of the reflective ESS element array, and the center point coordinates of each reflective ESS element are determined. Calculate the normal and tangential vectors at each center point and establish a local coordinate system; Based on the reflection phase of each reflective ESS unit, a corresponding I-shaped metal patch is generated in each local coordinate system, and integrated with the curved substrate through Boolean operations to generate a curved electromagnetic protection structure model.

[0010] In one embodiment, the length of the horizontal strip of the I-shaped metal patch can be adjusted from 4 mm to 24 mm.

[0011] In one embodiment, the PIN diode is equivalent to a capacitor in the off state and to a series resistor and inductor in the on state.

[0012] In one embodiment, the reflector antenna of the large-aperture parabolic antenna to be protected has an aperture size of 600mm and a focal length of 218.75mm, and the feed adopts an S-band standard rectangular open waveguide.

[0013] In one embodiment, the arrangement period of the reflective ESS unit is 25 mm.

[0014] In one embodiment, the width of the longitudinal arm is 3.5 mm and the length of the longitudinal arm is 14 mm.

[0015] An electromagnetic protection device based on random phase, the device comprising: The unit array construction module is used to construct a reflective ESS unit array based on Huygens' principle, according to the reflective surface curved configuration of the large-aperture parabolic antenna to be protected. The reflective ESS unit includes an I-shaped metal patch, an air dielectric layer, and a metal backplate arranged from top to bottom. The longitudinal arm of the I-shaped metal patch is provided with a gap, and a PIN diode is loaded in the gap to evenly divide the I-shaped metal patch. The reflection phase construction module is used to construct the reflection phase of each reflective ESS unit under protection conditions using a wide-range random phase distribution method. The electromagnetic protection module is used to establish a parametric surface model based on the reflector surface configuration of the large-aperture parabolic antenna to be protected. It maps and integrates the phase-reconfigurable reflective ESS elements one by one to the corresponding positions of the parametric surface model to generate a surface electromagnetic protection structure model.

[0016] The aforementioned electromagnetic protection method and device based on random phase constructs a wide-range random reflection phase distribution, thereby uniformly dispersing the incident high-power electromagnetic energy signal in all directions of space under protective conditions, significantly reducing the electromagnetic energy entering the feed source and achieving efficient and stable electromagnetic protection. By establishing a parametric surface model and mapping and integrating reflective ESS elements to their corresponding positions on the parametric surface model, high-precision and high-efficiency integration of reflective ESS elements on arbitrarily complex surfaces is achieved using surface parametric modeling and element mapping methods. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating an electromagnetic protection method based on random phase in one embodiment; Figure 2 This is a schematic diagram of a reflector antenna model of a large-aperture parabolic antenna to be protected in one embodiment; Figure 3 This is a schematic diagram of a reflective ESS unit in one embodiment; Figure 4 This is a reflection phase curve diagram of a reflective ESS unit under different structural parameters in one embodiment, wherein, Figure 4 (a) is the reflection phase curve of the diode in the off state. Figure 4 (b) is the reflection phase curve of the diode in the on state; Figure 5 This is a top view of a curved ESS array employing a wide range of random phase distribution in one embodiment; Figure 6 This is a comparison of the E-plane radiation pattern of a large-aperture parabolic antenna before and after the addition of a curved electromagnetic protection structure in one embodiment. Figure 7This is a three-dimensional radiation pattern of a large-aperture parabolic antenna under two states after adding a curved electromagnetic protection structure in one embodiment. Figure 7 (a) shows the three-dimensional radiation pattern of a large-aperture parabolic antenna in the cutoff state. Figure 7 (b) is the three-dimensional radiation pattern of the large-aperture parabolic antenna in the conducting state; Figure 8 This is a phase distribution diagram of the electromagnetic field on the reflective surface of a large-aperture parabolic antenna under two states in one embodiment, after adding a reflective protection structure with random phase. Figure 8 (a) shows the electric field phase distribution in the diode's off state. Figure 8 (b) shows the magnetic field phase distribution in the diode's cutoff state. Figure 8 (c) shows the electric field phase distribution in the diode's on-state. Figure 8 (d) shows the magnetic field phase distribution when the diode is in the conducting state; Figure 9 This is a structural block diagram of an electromagnetic protection device based on random phase in one embodiment. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] In one embodiment, refer to Figure 1 An electromagnetic protection method based on random phase is provided, the method comprising the following steps: Step 201: Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, and based on Huygens' principle, construct a reflective ESS element array consisting of reflective ESS elements arranged at a fixed period size. The reflective ESS element includes an I-shaped metal patch, an air dielectric layer, and a metal backplate arranged from top to bottom. The longitudinal arm of the I-shaped metal patch has a gap, and a PIN diode is loaded in the gap to evenly divide the I-shaped metal patch.

[0020] Reflective ESS unit such as Figure 3 As shown.

[0021] Step 202: The reflection phase of each reflective ESS element under protection is constructed using a wide-range random phase distribution method.

[0022] Step 203: Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, establish a parameterized surface model, map and integrate the phase-reconfigurable reflective ESS elements one by one to the corresponding positions of the parameterized surface model, and generate a surface electromagnetic protection structure model.

[0023] In the aforementioned electromagnetic protection method based on random phase, a wide-range random reflection phase distribution is constructed to uniformly disperse the incident high-power electromagnetic energy signal in all directions of space under protective conditions, significantly reducing the electromagnetic energy entering the feed source and achieving efficient and stable electromagnetic protection. By establishing a parametric surface model and mapping and integrating the reflective ESS elements to their corresponding positions on the parametric surface model, high-precision and high-efficiency integration of reflective ESS elements on arbitrarily complex surfaces is achieved using surface parametric modeling and element mapping methods.

[0024] Based on the curved reflector configuration of the large-aperture parabolic antenna to be protected, this invention presents a protective design for nonlinear reconstruction of the surface electromagnetic flow phase, based on Huygens' principle.

[0025] It should be noted that Huygens' principle states that the equiphase surface of an electromagnetic wave at any given time can be equivalent to several Huygens units. Each Huygens unit can act as a new radiation source, and the resulting field is the superposition of the radiation fields generated by the equivalent currents and magnetic currents of all Huygens units. Understandably, after being excited by an incident wave, each reflective ESS unit is equivalent to a source of a secondary spherical wavelet, and the wavefront at subsequent times is the tangent plane of the envelopes of these wavelets. When the phases of the reflective ESS units are randomly distributed, the interference between the wavelets causes energy to disperse in space without a fixed main lobe direction, thereby suppressing strong reflected echoes and achieving reflective electromagnetic protection.

[0026] In one embodiment, reference Figure 2 The reflector antenna of the large-aperture parabolic antenna to be protected has an aperture size of 600mm and a focal length of 218.75mm. The feed adopts an S-band standard rectangular open waveguide.

[0027] In one embodiment, the length of the horizontal strip of the I-shaped metal patch is adjustable.

[0028] In this embodiment, the length of the horizontal strip of the I-shaped metal patch is adjusted. a This enables wide-range continuous control of the reflected phase within a broad phase range while the diode is in conduction mode (i.e., electromagnetic protection mode), without the need for external control circuitry. It features fast response speed, high reliability, and reconstruction of the phase characteristics of the reflective ESS unit.

[0029] For incident electromagnetic waves with electric field polarization parallel to the diode direction, the length of the horizontal stripe of the reflective ESS cell in different I-shaped metal patches is obtained through full-wave simulation. a Below are the reflection phase curves of the diode in the off and on states, as shown in the figure. Figure 4 As shown, simulation results indicate that when the diode is off (corresponding to normal signal incidence), the reflected phase changes with...a The changes are small, with a phase variation of less than 15° in the 2.75GHz~3.2GHz range, which can be considered consistent; when the diode is turned on (corresponding to the incident high-power electromagnetic signal), the reflected phase changes with... a The phase changes significantly with increasing frequency, exceeding 250° within the 2.75GHz to 3.2GHz range, achieving wide-range continuous tunability over a broad phase range. This demonstrates that the reflective ESS unit designed in this invention can achieve effective nonlinear reconstruction of the surface electromagnetic current distribution under protected conditions, thus meeting the design objectives.

[0030] In one embodiment, the length of the horizontal strip of the I-shaped metal patch can be adjusted from 4 mm to 24 mm.

[0031] In one embodiment, the arrangement period of the reflective ESS unit is 25 mm.

[0032] In one embodiment, the width of the longitudinal arm is 3.5 mm and the length of the longitudinal arm is 14 mm.

[0033] Specifically, refer to Figure 3 Width of the longitudinal arm sw The length of the trailing arm is 3.5mm. l The arrangement period of the reflective ESS unit is 14mm. P The gap width set for the longitudinal arm is 25mm. g It is 1mm.

[0034] In one embodiment, the PIN diode is equivalent to a capacitor in the off state and to a series resistor and inductor in the on state.

[0035] Specifically, the PIN diode is an SMP1345 type, which is equivalent to a capacitor C in the off state. p =0.15pF, the equivalent series resistance R in the on-state is 0.15pF. s =3Ω and inductance L p =0.45nH.

[0036] In one embodiment, step 202, constructing the reflection phase of each reflective ESS element in the protected state using a wide-range random phase distribution method, includes: Within a wide phase range, the reflection phase of each reflective ESS cell is randomly generated, and the reflection phases of all reflective ESS cells are independent of each other and follow a uniform random distribution.

[0037] Specifically, within a wide phase range, that is, from 0° to greater than 250°, the phase can be understood as... The range is , It can achieve wide phase coverage and realize effective nonlinear reconstruction of surface electromagnetic flow distribution under protective conditions.

[0038] After generating the reflection phase of each reflective ESS unit, according to Figure 4 The obtained reflection phase and a The correspondence is used to map each reflection phase value to the corresponding... a This allows us to determine the specific geometric parameters of each reflective ESS element.

[0039] In one embodiment, step 203 involves establishing a parameterized surface model based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, mapping and integrating the phase-reconfigurable reflective ESS elements one by one to the corresponding positions in the parameterized surface model, and generating a surface electromagnetic protection structure model, including: Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, a parameterized surface equation is established. The grid is divided according to the period of the reflective ESS element array, and the center point coordinates of each reflective ESS element are determined. Calculate the normal and tangential vectors at each center point and establish a local coordinate system; Based on the reflection phase of each reflective ESS unit, a corresponding I-shaped metal patch is generated in each local coordinate system, and integrated with the curved substrate through Boolean operations to generate a curved electromagnetic protection structure model.

[0040] Specifically, based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, a parameterized surface equation is established. The array is then meshed according to the period of the reflective ESS element array to determine the coordinates of the center point of each reflective ESS element. The normal and tangential vectors of each center point are calculated to establish a local coordinate system. Finally, each reflective ESS element is confirmed using its reflection phase value. a A loop is constructed to generate corresponding I-shaped metal patches in each local coordinate system, and then integrated with the curved surface substrate through Boolean operations to generate a curved electromagnetic protection structure model.

[0041] Reference Figure 5 , Figure 5 To generate a top view of the curved electromagnetic shielding structure model, which contains 449 reflective ESS elements. In each reflective ESS element, the length of the horizontal strips of the I-shaped metal patch is randomly distributed within the range of 4mm to 24mm, and the corresponding reflection phase is randomly distributed within a wide phase range.

[0042] To verify the effectiveness of this invention, the generated curved electromagnetic protection structure model was mounted on the large-aperture parabolic antenna model to be protected (located between the reflector and the feed, 8mm from the reflector), establishing an integrated electromagnetic simulation model. Plane wave excitation was set at a frequency of 2.76GHz. The E-plane radiation pattern of the antenna was calculated under two states (diode cutoff state, simulating normal signal incidence; diode conduction state, simulating high-power electromagnetic signal incidence). The results are as follows: Figure 6 As shown, in the cutoff state, after adding the curved electromagnetic protection structure, the antenna's main lobe gain, beamwidth, and sidelobe level are compared with those without the structure. Figure 6 The curves of the original antenna are basically consistent, and the average insertion loss in the -10dB beam range of the main lobe is less than 0.1dB, indicating that the curved electromagnetic protection structure has little impact on the normal reception performance of the antenna. When in the conducting state, the gain of the original antenna main lobe position (near Theta=0°) drops significantly, the average attenuation of the radiated field strength in the -10dB beam range is about 15.87dB, and the attenuation at Theta=0° exceeds 25dB. Figure 7 The three-dimensional radiation patterns in the two states are shown, which intuitively demonstrate that in the conducting state, the electromagnetic energy originally concentrated in the main lobe is dispersed to various directions in space, achieving the protective effect of "weak field focusing and strong field defocusing".

[0043] The tangential electric and magnetic field phase distributions on the inner surface of the reflecting surface under two states are obtained by setting up a field monitor, such as... Figure 8 As shown in (a) and (b), in the cutoff state, the phase distribution exhibits a uniform change from the center to the outside, indicating the formation of a good spherical wavefront, and the electromagnetic wave is focused onto the feed source; as Figure 8 As shown in (c) and (d), in the conducting state, the phase distribution becomes chaotic (the reflected phase of each unit is randomly distributed over a wide phase range), which disrupts the formation conditions of the spherical wavefront, causing the electromagnetic wave to no longer converge at the feed source, but instead scatter freely into space. This physically verifies the effective dispersion of incident high-power electromagnetic energy signals by a full-range random phase distribution.

[0044] It can be seen that the electromagnetic protection method based on random phase proposed in this invention can effectively cope with the influence of high-power electromagnetic signals while ensuring the normal receiving performance of large-aperture parabolic antennas. It has the advantages of low insertion loss, high protection efficiency, fast response speed and good conformal integration.

[0045] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0046] In one embodiment, such as Figure 9 As shown, an electromagnetic protection device based on random phase is provided, the device comprising: The unit array construction module 901 is used to construct a reflective ESS unit array based on the reflective surface curved configuration of the large-aperture parabolic antenna to be protected, and on the basis of Huygens' principle. The reflective ESS unit includes an I-shaped metal patch, an air dielectric layer, and a metal backplate arranged from top to bottom. The longitudinal arm of the I-shaped metal patch is provided with a gap, and a PIN diode is loaded in the gap to evenly divide the I-shaped metal patch.

[0047] The reflection phase construction module 902 is used to construct the reflection phase of each reflective ESS unit in the protection state using a wide-range random phase distribution method.

[0048] Electromagnetic protection module 903 is used to establish a parametric surface model based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, and to map and integrate the phase-reconfigurable reflective ESS elements one by one to the corresponding positions of the parametric surface model to generate a surface electromagnetic protection structure model.

[0049] Specific limitations regarding random phase-based electromagnetic protection devices can be found in the above description of the limitations of random phase-based electromagnetic protection methods, and will not be repeated here. Each module in the aforementioned random phase-based electromagnetic protection device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.

[0050] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. An electromagnetic protection method based on random phase, characterized in that, The method includes the following steps: Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, and based on Huygens' principle, a reflective ESS element array is constructed, consisting of reflective ESS elements arranged in a fixed period size. The reflective ESS element includes an I-shaped metal patch, an air dielectric layer, and a metal backplate arranged from top to bottom. The longitudinal arm of the I-shaped metal patch has a gap, and a PIN diode is loaded in the gap to evenly divide the I-shaped metal patch. The reflection phase of each reflective ESS element under protection is constructed using a wide-range random phase distribution method; Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, a parameterized surface model is established. The phase-reconfigurable reflective ESS elements are mapped one by one and integrated into the corresponding positions of the parameterized surface model to generate a surface electromagnetic protection structure model.

2. The electromagnetic protection method based on random phase according to claim 1, characterized in that, The length of the horizontal strip of the I-shaped metal patch is adjustable.

3. The electromagnetic protection method based on random phase according to claim 1, characterized in that, The reflection phase of each reflective ESS element in the protected state is constructed using a wide-range random phase distribution method, including: Within a wide phase range, the reflection phase of each reflective ESS cell is randomly generated, and the reflection phases of all reflective ESS cells are independent of each other and follow a uniform random distribution.

4. The electromagnetic protection method based on random phase according to claim 3, characterized in that, Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, a parameterized surface model is established. Phase-reconfigurable reflective ESS elements are mapped and integrated one by one into the corresponding positions of the parameterized surface model, generating a surface electromagnetic protection structure model, including: Based on the reflector surface configuration of the large-aperture parabolic antenna to be protected, a parameterized surface equation is established. The grid is divided according to the period of the reflective ESS element array, and the center point coordinates of each reflective ESS element are determined. Calculate the normal and tangential vectors at each center point and establish a local coordinate system; Based on the reflection phase of each reflective ESS unit, a corresponding I-shaped metal patch is generated in each local coordinate system, and integrated with the curved substrate through Boolean operations to generate a curved electromagnetic protection structure model.

5. The electromagnetic protection method based on random phase according to claim 2, characterized in that, The length of the horizontal strip of the I-shaped metal patch can be adjusted from 4mm to 24mm.

6. The electromagnetic protection method based on random phase according to claim 1, characterized in that, The PIN diode is equivalent to a capacitor in the off state and to a series resistor and inductor in the on state.

7. The electromagnetic protection method based on random phase according to claim 1, characterized in that, The large-aperture parabolic antenna to be protected has a reflector antenna aperture of 600mm and a focal length of 218.75mm. The feed source adopts an S-band standard rectangular open waveguide.

8. The electromagnetic protection method based on random phase according to claim 7, characterized in that, The arrangement period of the reflective ESS unit is 25mm.

9. The electromagnetic protection method based on random phase according to claim 7, characterized in that, The width of the trailing arm is 3.5mm, and the length of the trailing arm is 14mm.

10. An electromagnetic protection device based on random phase, characterized in that, The device includes: The unit array construction module is used to construct a reflective ESS unit array based on Huygens' principle, according to the reflective surface curved configuration of the large-aperture parabolic antenna to be protected. The reflective ESS unit includes an I-shaped metal patch, an air dielectric layer, and a metal backplate arranged from top to bottom. The longitudinal arm of the I-shaped metal patch is provided with a gap, and a PIN diode is loaded in the gap to evenly divide the I-shaped metal patch. The reflection phase construction module is used to construct the reflection phase of each reflective ESS unit under protection conditions using a wide-range random phase distribution method. The electromagnetic protection module is used to establish a parametric surface model based on the reflector surface configuration of the large-aperture parabolic antenna to be protected. It maps and integrates the phase-reconfigurable reflective ESS elements one by one to the corresponding positions of the parametric surface model to generate a surface electromagnetic protection structure model.

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