Wing edge diffraction suppression and RCS reduction amplitude regulation and control method
By establishing the edge diffraction suppression theoretical model of irregular edge wings, an irregular edge wing model was calculated and designed, and RCS reduction of more than 12dB in the frequency band of 3.3GHz~40GHz and 20°<θ<90° incident angle range was achieved, solving the problem of backward radar scattering cross-section enhancement caused by the aircraft edge diffraction effect.
Patent Information
- Application Number
- CN202510076867.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2025-05-23
AI Technical Summary
The prior art is difficult to effectively suppress the enhanced cross-section of the backward radar scattering caused by the diffraction effect of the wing edge of the aircraft, especially when TE and TM polarized waves are incident at high angles.
By establishing the theoretical model of edge diffraction suppression of irregular edge wings, an irregular edge wing model was calculated and designed to achieve RCS reduction of more than 12dB within the operating frequency band of 3.3GHz~40GHz and the incident angle range of 20°<θ<90°.
Significant RCS reduction in wide frequency bands and large angle incident conditions has been achieved, effectively solving the problem of backward radar scattering cross-section enhancement caused by aircraft edge diffraction.
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Figure CN120030673A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of stealth equipment, and in particular to a method for controlling wing edge diffraction suppression and RCS reduction amplitude. Background Art
[0002] In the design of high-value radar targets, Radar Cross Section (RCS) is a key indicator to measure the detectability of the target. Therefore, reducing RCS has become one of the core goals in modern aircraft design.
[0003] The technical means to achieve RCS reduction mainly include the application of absorbing materials, the use of curved air inlets, and the optimization of the shape to deviate the electromagnetic waves to the radar detection direction; by optimizing the shape design or applying absorbing materials, the main specular scattering can be effectively reduced or eliminated; however, due to the discontinuity of the target surface, especially when it comes to objects with sharp edges or large curvature changes (wings and missile edges), the edge diffraction effect caused has a particularly significant impact on the rear RCS.
[0004] The methods for suppressing edge diffraction are mainly divided into three categories: electromagnetic absorption, electromagnetic metasurface loading technology and edge shaping technology; electromagnetic absorption is to use absorbing materials to reduce the surface current of the metal conductive layer to achieve the purpose of reducing the rear RCS, however, its narrow band, heavy weight and high price limit its application scope; electromagnetic metasurface loading technology achieves the purpose of suppressing edge diffraction by loading tapered periodic sheets (TPS) on the edge to achieve impedance continuity and smooth transition of surface current. However, the narrowband characteristics of TPS are difficult to meet the requirements of multi-band stealth; edge shaping technology deviates its energy from the radar detection direction by shaping the edge, however, the design of the sawtooth size requires continuous optimization and iteration, therefore, the present invention proposes a method for controlling the amplitude of wing edge diffraction suppression and RCS reduction to solve the problems existing in the prior art. Summary of the invention
[0005] In view of the above problems, the purpose of the present invention is to propose a wing edge diffraction suppression and RCS reduction amplitude control method to solve the problem of backscattering radar cross section enhancement caused by aircraft edge diffraction under large-angle incidence of TE and TM polarized waves. The wing edge diffraction suppression and RCS reduction amplitude control method realizes an irregular edge wing model designed by edge diffraction suppression theoretical model calculation, and realizes an operating frequency band of 3.3GHz~40GHz, an incident angle of 20°< In the range of <90°, the RCS reduction of more than 12dB effectively solves the above problems.
[0006] To achieve the purpose of the present invention, the present invention is implemented by the following technical solution: a method for controlling wing edge diffraction suppression and RCS reduction amplitude, comprising the following steps: Step 1: Establish a theoretical model for edge diffraction suppression of irregular edge wings; Step 2: Set the initial frequency , stop frequency , reduction and the incident angle of the plane wave ; Step 3: Calculate the number of sub-regions N and the unit length of the sub-regions based on the model in step 1 and the parameters in step 2 and variables The value of Step 4: Calculate the length distribution of N rectangular sub-areas using the Babel formula; Step 5: Establish a wing model with regular concave and convex edges according to the calculated N sawtooth length distributions, and complete the wing edge diffraction suppression amplitude regulation according to the model.
[0007] A further improvement is that: the theoretical model establishment process in step 1 is: when the irregular edge wing constructed is composed of N rectangular sub-regions of different lengths, the electromagnetic wave is The RCS reduction function of N irregular wing edges of different lengths is expressed by the following formula based on the one-dimensional N-element array factor function of array theory and the multivariate phase cancellation principle: Assume that the amplitude of N units With respect to central symmetry, the corresponding relationship between the RCS reduction function and the Chebyshev polynomial is constructed, , , after normalization, the cosine form of the RCS reduction function is expressed as follows From It is concluded that the RCS reduction function is expressed as a cosine function. At the same time, the RCS reduction function with an odd total number of sub-regions corresponds to an even-order Chebyshev polynomial, and the RCS reduction function with an even total number of sub-regions corresponds to an odd-order Chebyshev polynomial. make =R, 20log (R) is the pre-given RCS reduction value, and thus a mapping relationship based on Chebyshev polynomials to achieve equal-amplitude RCS reduction is established. Based on this given reduction value, the R value can be obtained. From R and the number of sub-regions N, the m=N-1 order Chebyshev polynomial can be obtained. , that is, if it is realized The RCS reduction of Chebyshev equation is expressed as follows According to the definition of the solution of the Chebyshev function, we get the following formula From It can be concluded that The value of is determined by the number of sub-regions N and the reduction value R. , in the first cycle The starting frequency of the equal amplitude reduction is expressed by the following formula make , in the first cycle The end frequency of the equal amplitude reduction is expressed by the following formula In the first cycle The relative bandwidth of equal amplitude reduction is expressed by the following formula That is, the theoretical model is obtained.
[0008] A further improvement is that the variable According to the formula Calculate the number of sub-regions N according to the formula Calculate the unit length of the sub-region According to the formula calculate.
[0009] A further improvement is that: in step 4, when N is an even number, N=2M When N is an odd number, N=2M+1 .
[0010] The beneficial effects of the present invention are as follows: the present invention realizes the working frequency range of 3.3GHz~40GHz and the incident angle of 20°< In the range of <90°, the RCS reduction of more than 12dB effectively solves the problem of enhanced backscattering radar cross section caused by diffraction at the edge of the aircraft under large-angle incidence of TE and TM polarized waves, and provides a reliable control method for the key indicators of high-value radar target design. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 This is a schematic diagram of the edge wing of Example 2 of the present invention.
[0012] Figure 2Schematic diagram of the length of N serrated irregular edge wings in Example 2 of the present invention.
[0013] Figure 3 In Example 2 of the present invention The RCS reduction of theoretical calculation and simulation varies with frequency when the angle is 70°.
[0014] Figure 4 The TE polarized wave in Example 2 of the present invention is When the incident angle is 70° and vertical to the edge of the wing =11.365° plane bi-station RCS distribution diagram.
[0015] Figure 5 The TM polarized wave in Example 2 of the present invention is When the incident angle is 70° and vertical to the edge of the wing =0° plane bi-station RCS distribution diagram.
[0016] Figure 6 This is the RCS heat map of the regular edge wing of the electromagnetic wave at 0°~90°&1~40GHz in Example 2 of the present invention.
[0017] Figure 7 This is the RCS heat map of the irregular edge wing of the electromagnetic wave at 0°~90°&1~40GHz in Example 2 of the present invention.
[0018] Figure 8 This is a heat map of the RCS reduction of the irregular edge wing of the electromagnetic wave at 0°~90°&1~40GHz in Example 2 of the present invention. DETAILED DESCRIPTION
[0019] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.
[0020] Example 1 This embodiment provides a method for controlling wing edge diffraction suppression and RCS reduction amplitude, comprising the following steps: Step 1: Establish a theoretical model for edge diffraction suppression of irregular edge wings; The theoretical model establishment process is as follows: When the irregular edge wing is composed of N rectangular sub-regions of different lengths, the electromagnetic wave is The RCS reduction function of N irregular wing edges of different lengths is expressed by the following formula based on the one-dimensional N-element array factor function of array theory and the multivariate phase cancellation principle: Assume that the amplitude of N units With respect to central symmetry, the corresponding relationship between the RCS reduction function and the Chebyshev polynomial is constructed, , , after normalization, the cosine form of the RCS reduction function is expressed as follows From It is concluded that the RCS reduction function is expressed as a cosine function. At the same time, the RCS reduction function with an odd total number of sub-regions corresponds to an even-order Chebyshev polynomial, and the RCS reduction function with an even total number of sub-regions corresponds to an odd-order Chebyshev polynomial. make =R (R dimensionless), 20log (R) is the pre-given RCS reduction value, thus establishing a mapping relationship based on Chebyshev polynomials to achieve equal-amplitude RCS reduction. Based on this given reduction value, the R value can be obtained. From R and the number of sub-regions N, the m=N-1 order Chebyshev polynomial can be obtained. , that is, if it is realized The RCS reduction of Chebyshev equation is expressed as follows According to the definition of the solution of the Chebyshev function, we get the following formula From It can be concluded that The value of is determined by the number of sub-regions N and the reduction value R. , in the first cycle The starting frequency of the equal amplitude reduction is expressed by the following formula make , in the first cycle The end frequency of the equal amplitude reduction is expressed by the following formula In the first cycle The relative bandwidth of equal amplitude reduction is expressed by the following formula That is, the theoretical model of RCS reduction based on Chebyshev polynomials and multivariate phase cancellation is obtained.
[0021] Step 2: Set the initial frequency 3.3GHz, end frequency 40GHz, reduced amplitude is 12dB and the incident angle of the plane wave is 70°.
[0022] Step 3: Calculate based on the model in step 1 and the parameters in step 2. Specifically, according to the formula Calculate the number of sub-regions N, according to the formula Calculate the sub-area unit length And according to the formula Calculated variables The numerical value of .
[0023] Step 4: Calculate the length distribution of N rectangular sub-areas using the Babel formula; When N is an even number, N=2M When N is an odd number, N=2M+1 Step 5: Establish a wing model with regular concave and convex edges according to the calculated N sawtooth length distributions, and complete the wing edge diffraction suppression amplitude regulation according to the model.
[0024] Example 1 according to Figure 1-Figure 8 As shown, this embodiment provides an example of a method for controlling wing edge diffraction suppression and RCS reduction amplitude.
[0025] As the instruction manual Figure 1 As shown in (b), the designed irregular edge wing is trapezoidal (a in the figure is a regular edge wing), with the right angle waist (wing trailing edge) and the oblique waist (wing leading edge) lengths of 600mm and 612mm respectively. The irregular edge wing is composed of 30 serrations of different lengths. The specific lengths are as shown in the attached manual. Figure 2 As shown. Among them, the width of the rectangular block of the right-angle waist 20 mm, rectangular sawtooth width with oblique waist The wing has a sheet metal thickness of 3 mm.
[0026] As the instruction manual Figure 2 What is shown is a length diagram of N sawtooth irregular edge wings, and the specific size derivation process is calculated by formulas (4) to (9) in Example 1.
[0027] As the instruction manual Figure 3 Shown is The graph of the RCS reduction with frequency when the angle of the angular displacement is 70° shows that the sawtooth irregular edge wing achieves an equal-amplitude RCS reduction of 12 dB for TE polarized waves (Figure a) and TM polarized waves (Figure b) in the target frequency band of 3.3 GHz to 40 GHz. It should be pointed out that this equal-amplitude RCS reduction means that the sidelobe peak remains consistent throughout the frequency band, rather than the idealized situation where the RCS reduction value is exactly the same throughout the frequency band. The theoretical calculation results are consistent with the simulation data as a whole, which fully demonstrates the effectiveness of the irregular edge wing design based on Chebyshev polynomials in ultra-wideband edge diffraction suppression and RCS reduction amplitude regulation.
[0028] As the instruction manual Figure 4 The TE polarized wave is shown in When the incident angle is 70° and vertical to the edge of the wing =11.365° plane. At the representative frequencies of 4GHz (a in the figure), 15GHz (b in the figure), 25GHz (c in the figure) and 35GHz (d in the figure), the bistatic RCS results show that compared with the regular edge wing, the sawtooth irregular edge wing shows a significant RCS reduction effect in the backward range of 0°~180°.
[0029] As the instruction manual Figure 5 The TM polarized wave is shown in When the incident angle is 70° and vertical to the edge of the wing =0° plane. At the representative frequencies of 4 GHz (a in the figure), 15 GHz (b in the figure), 25 GHz (c in the figure) and 35 GHz (d in the figure), the bistatic RCS results show that compared with the regular edge wing, the sawtooth irregular edge wing exhibits a significant RCS reduction effect in the backward range of 0°~180°.
[0030] As the instruction manual Figure 6 Shown are the RCS heat maps of the regular edge wing at 0°~90°&1~40GHz for electromagnetic waves TE polarized waves (Figure a) and TM polarized waves (Figure b).
[0031] As the instruction manual Figure 7 The RCS heat map of the TE polarized wave (a) and TM polarized wave (b) of the irregular edge wing at 0°~90°&1~40GHz is shown. Compared with the RCS heat map of the regular edge wing, the RCS of the irregular edge wing is significantly reduced.
[0032] As the instruction manual Figure 8 The RCS reduction heat map of the TE polarized wave (a) and TM polarized wave (b) at 0°~90°&1~40GHz of the irregular edge wing is shown. <20°, the RCS reduction value tends to 0, which is mainly due to the mirror reflection of the backscattered field; in the medium and large incident angle range (20°< <75°, most frequency bands achieve an RCS reduction greater than 12dB; at large incident angles (75°< <90°), the RCS reduction effect in the low-frequency band is more significant, while a blind spot of RCS reduction appears in the high-frequency band (near 40 GHz). This is because as the incident angle increases, the corresponding RCS reduction blind spot moves toward the low frequency, but the relative bandwidth remains unchanged.
[0033] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.
Claims
1. A method for controlling wing edge diffraction suppression and RCS reduction amplitude, characterized in that: The following steps are involved: Step 1: Establish a theoretical model for edge diffraction suppression of irregular edge wings; Step 2: Set the initial frequency , stop frequency , reduction and the incident angle of the plane wave ; Step 3: According to the theoretical model in step 1, the number of sub-regions N and the unit length of the sub-regions are calculated in combination with the parameters in step 2. and variables The value of Step 4: Calculate the length distribution of N rectangular sub-areas using the Babel formula; Step 5: Establish a concave-convex irregular edge wing model based on the calculated N sawtooth length distributions, and complete the wing edge diffraction suppression and RCS reduction amplitude regulation based on the model.
2. A method for controlling wing edge diffraction suppression and RCS reduction amplitude according to claim 1, characterized in that: The theoretical model establishment process in step 1 is as follows: when the irregular edge wing constructed is composed of N rectangular sub-regions of different lengths, the electromagnetic wave When incident to the radar detection target, according to the one-dimensional N-unit array factor function in array theory and the principle of multivariate phase cancellation, the RCS reduction function of N irregular wing edges of different lengths is expressed by the following formula: Assume that the amplitude of N units With respect to central symmetry, the corresponding relationship between the RCS reduction function and the Chebyshev polynomial is constructed, , , after normalization, the cosine form of the RCS reduction function is expressed as follows From It is concluded that the RCS reduction function is expressed as a cosine function. At the same time, the RCS reduction function with an odd total number of sub-regions corresponds to an even-order Chebyshev polynomial, and the RCS reduction function with an even total number of sub-regions corresponds to an odd-order Chebyshev polynomial. make =R, 20log (R) is the pre-given RCS reduction value, and thus a mapping relationship based on Chebyshev polynomials to achieve equal-amplitude RCS reduction is established; based on this given reduction value, the R value can be obtained, and from R and the number of sub-regions N, the m=N-1 order Chebyshev polynomial can be obtained. , that is, if it is realized The RCS reduction of Chebyshev equation is expressed as follows According to the definition of the solution of the Chebyshev function, we get the following formula From It can be concluded that The value of is determined by the number of sub-regions N and the reduction value R. , in the first cycle The starting frequency of the equal amplitude reduction is expressed by the following formula make , in the first cycle The end frequency of the equal amplitude reduction is expressed by the following formula In the first cycle The relative bandwidth of equal amplitude reduction is expressed by the following formula That is, the theoretical model is obtained.
3. A method for controlling wing edge diffraction suppression and RCS reduction amplitude according to claim 2, characterized in that: The variable According to the formula Calculate the number of sub-regions N according to the formula Calculate the unit length of the sub-region According to the formula calculate.
4. The method for controlling wing edge diffraction suppression and RCS reduction amplitude according to claim 1, characterized in that: In step 4, when N is an even number, N=2M When N is an odd number, N=2M+1