Large-scale digital array antenna design method and device for stratospheric airship-borne radar
By designing a large-scale digital array antenna for stratospheric airships, using a fully digital orientation and pitch beamforming scheme, combining genetic algorithms to optimize unit amplitude and phase, the problem of insufficient timeliness and continuity of the aerospace radar in regional information guarantee is solved, and efficient long-distance monitoring and detection is achieved.
Patent Information
- Application Number
- CN202510546644.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-28
- Publication Date
- 2025-08-15
AI Technical Summary
In the prior art, the timeliness and continuity of the regional information guarantee of the aerospace radar is insufficient, the traditional space-based, air-based and ground-based radars lack long-range threat warning capabilities, and there is a lack of public reports on the research on large-scale array antennas of the aerospace device.
A large-scale digital array antenna for stratospheric airships was designed, and a digital array antenna scheme with azimuth and pitch beam shape was adopted. Combined with genetic algorithms to optimize the unit amplitude and phase, it realized a 96-unit full digital architecture and a 10-unit series feeding array, meeting the lightweight and low power consumption requirements of large-scale array antennas.
It has achieved large-scale and high-sensitivity monitoring and detection capabilities, overcomes the contradiction between large-scale array antennas and lightweight and low-power consumption, provides a solid technical foundation for stratospheric airship radar, and improves detection distance and anti-interference capabilities.
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Figure CN120493701A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of radar antennas, and in particular relates to a design method and device for a large-scale digital array antenna of a stratospheric airship-borne radar. Background Art
[0002] Integrated land, sea, air, and space early warning and detection is a key future development direction for radar technology. Aerostats utilize the buoyancy provided by gases with a lower density than air (such as helium) to propel themselves. They offer advantages such as long-term persistence, strong survivability, high cost-effectiveness, large payload capacity, and excellent stealth. Traditional space-based radars are limited by their orbits and constellation size, resulting in significant shortcomings in the timeliness and continuity of regional information assurance. Air-based radars, on the other hand, are limited by their flight speed and altitude, resulting in limited sensing range and sustained operation. Ground-based and sea-based radars are hampered by the curvature of the Earth and the concealment of terrain, making them difficult to provide long-range threat warnings. In contrast, aerostat-borne radars offer superior early warning capabilities, effectively addressing the shortcomings of existing early warning methods and enabling large-scale, highly sensitive, and continuous reconnaissance and surveillance in both the air and sea. Furthermore, due to their different detection angles, aerostat-borne radars also possess certain anti-stealth capabilities. Currently, research on aerostat-borne radars primarily focuses on tethered sphere platforms, which demonstrate significant surveillance and detection capabilities.
[0003] Research on stratospheric airship-borne radars has primarily focused on evaluating radar system performance and optimizing imaging algorithms. However, there is a lack of public coverage of research on large-scale array antennas mounted on aerostats. Therefore, we are focusing on enhancing the high-altitude surveillance and reconnaissance potential of aerostat-borne radars, particularly in areas such as the combined design of radar systems and large-scale array antennas, and innovative optimization of signal processing algorithms, to promote the advancement and application of related technologies. Summary of the Invention
[0004] To solve the above technical problems, the present invention provides a design method and device for a large-scale digital array antenna for stratospheric airship-borne radar. Following the design principle of maximizing radar performance, the present invention demonstrates the overall technical requirements of the stratospheric airship-borne radar antenna, proposes a digital array antenna solution with full digital in azimuth and beamforming in elevation, studies key digital array beamforming technologies such as beamforming, simultaneous multi-beam, and adaptive interference suppression, and provides test results of the large-scale digital array antenna for stratospheric airship-borne radar, providing a solid technical foundation for the application of stratospheric airship-borne radar.
[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:
[0006] In one aspect, the present invention provides a method for designing a large-scale digital array antenna for a stratospheric airship-borne radar, the method comprising:
[0007] Step 1: Calculate the technical requirements of the array antenna based on the stratospheric airship platform parameters and radar detection requirements;
[0008] Step 2: Based on the technical requirements, design a digital array antenna that is fully digital in azimuth and beam-forming in elevation, and use a genetic algorithm to optimize the unit amplitude and phase of the digital array antenna; the digital array antenna includes a 96-unit fully digital architecture in azimuth and a 10-unit series-fed beamforming array in elevation.
[0009] In another aspect, the present invention provides a device for designing a large-scale digital array antenna for a stratospheric airship-borne radar, comprising:
[0010] A calculation module is used to calculate the technical requirements of the array antenna based on the stratospheric airship platform parameters and radar detection requirements;
[0011] The output module is used to design a digital array antenna that is fully digital in azimuth and beam-forming in elevation according to the technical requirements, and to optimize the element amplitude and phase of the digital array antenna using a genetic algorithm; the digital array antenna includes a 96-element fully digital architecture in azimuth and a 10-element series-fed beamforming array in elevation.
[0012] In a third aspect, the present invention provides an electronic device comprising: one or more processors; and a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned method for designing a large-scale digital array antenna for a stratospheric airship-borne radar.
[0013] In a fourth aspect, the present invention provides a computer-readable storage medium having executable instructions stored thereon, which, when executed by a processor, enables the processor to implement the aforementioned method for designing a large-scale digital array antenna for a stratospheric airship-borne radar.
[0014] The beneficial effects of the present invention are:
[0015] Taking into account the platform's payload capacity and power limitations, the design requirements for stratospheric airship-borne radar antennas were clarified, and a digital array antenna design scheme with fully digital azimuth and beamforming in elevation was proposed. This scheme overcomes the contradiction between the large-scale, wide-angle scanning design of the array antenna and the lightweight and low-power requirements of the stratospheric airship, providing a solid technical foundation for the application of stratospheric airship-borne radars. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 Flowchart of the design method for large-scale digital array antenna for stratospheric airship-borne radar;
[0017] Figure 2 Schematic diagram of the maximum detection range of radars on different platforms for targets at different altitudes;
[0018] Figure 3 This is a diagram showing the relationship between SNR and radar power;
[0019] Figure 4 Schematic diagram of the relationship between radar detection probability, false alarm rate and SNR;
[0020] Figure 5 This is a schematic diagram of the digital array antenna's elevation beam coverage;
[0021] Figure 6 Schematic diagram of the desired beam and cosecant square fitting results covering the target area;
[0022] Figure 7 Schematic diagram of objective function and beamforming results;
[0023] Figure 8 It is a schematic diagram of the array comprehensive amplitude value;
[0024] Figure 9 Schematic diagram of the array comprehensive phase value;
[0025] Figure 10 It is the simultaneous dual-beam pattern of the digital array antenna;
[0026] Figure 11 Adaptive interference suppression pattern for digital array antenna;
[0027] Figure 12 This is the test result of the digital array antenna pattern. DETAILED DESCRIPTION
[0028] The present invention will be further described below with reference to the accompanying drawings and examples.
[0029] The present invention provides a design method and device for a large-scale digital array antenna for a stratospheric airship-borne radar. First, from the perspective of the platform, the technical advantages of the stratospheric airship-borne radar are demonstrated, and the technical requirements of the array antenna are calculated based on the need to maximize the detection power of the airship-borne radar. Secondly, a digital array antenna scheme with full digital in azimuth and beamforming in elevation is proposed, and key technologies of digital array beamforming such as beamforming, simultaneous multi-beam and adaptive interference suppression are studied. Finally, the large-scale digital array antenna for the stratospheric airship-borne radar is tested to verify the effectiveness of the design method. Figure 1 As shown, specifically including:
[0030] Step 1: Calculate the technical requirements of the array antenna, including antenna gain, beam coverage, and detection range, based on the stratospheric airship platform parameters and radar detection requirements.
[0031] When a radar has sufficient power and sensitivity, its maximum detection range of a target is mainly determined by the line of sight. Taking into account the refraction effect of the atmosphere on electromagnetic waves, the radar's maximum line of sight to a target can be calculated using the following formula:
[0032] (1)
[0033] Where R is the radar viewing range in meters; h a is the radar lift-off height, in meters; h t is the target altitude in kilometers.
[0034] The detection distance of radars on different platforms for targets at different altitudes is as follows: Figure 2 As shown in the figure, a stratospheric airship can operate at an altitude of 20 km, far exceeding the maximum altitude of an aircraft of 8 km. Other platforms, such as manned airships, tethered spheres, and ground-based radars, operate at even lower altitudes. At an altitude of 20 km, the detection range of stratospheric airship radars for surface ships and other ground targets can reach 582 km, exceeding the 368 km range of airborne radars. This theoretically enables detection and early warning over a wider area at greater distances.
[0035] Considering the radar power and the anti-stealth characteristics of the dual-static system, the present invention adopts the L-band and dual-static system. According to the dual-static radar equation, the signal-to-noise ratio (SNR) after coherent integration can be expressed as:
[0036] (2)
[0037] Among them, SNR is the signal-to-noise ratio, in decibels; P av is the radiation source emission power, in watts; G t is the radiation source antenna gain, G r is the digital array antenna gain, in decibels; λ is the wavelength corresponding to the radar operating frequency, in meters; σ is the target radar cross section (RCS), in square meters; t is the radar exposure time, in seconds; R t is the distance from the radiation source to the target area, R r is the radar range in meters; k is the Boltzmann constant (1.38×10 -23 Joule / Kelvin); T0 is the effective noise temperature in Kelvin; F is the noise figure in decibels; L s is the radar loss in decibels.
[0038] The relationship between SNR and radar power is as follows Figure 3 As shown in FIG, the signal-to-noise ratio (SNR) is associated with the antenna gain and the detection range. That is, when the radar has a maximum detection range of 580 km, the signal-to-noise ratio (SNR) is 13.07 dB.
[0039] Detection probability Pd , signal-to-noise ratio (SNR) and false alarm probability The relationship between them is:
[0040] (3)
[0041] Where Q is the Marcum Q function.
[0042] Through this relationship, we can get the variation of detection probability with SNR under different false alarm probabilities. Figure 4 As shown in the figure, when the SNR is 13.05 dB, the corresponding detection probability is 0.85 and the false alarm probability is 10. -6 At this time, the corresponding digital array antenna gain is 32.8dBi. Therefore, the detection probability is 0.85 and the false alarm probability is 10. -6 Under the detection requirements of , the radar needs to achieve a maximum detection range of 580 km, and the array antenna gain must be greater than 32.8 dBi.
[0043] Figure 5 A schematic diagram of the elevation beam coverage of the airborne radar antenna is given. The stratospheric airship radar has a stationary altitude of 20 km, a maximum detection range of 582 km, and no beam coverage is required within a 50 km area. Calculations show that the elevation beam width of the digital array antenna is 19.83°. Assuming that the normal direction of the digital array antenna is horizontal, the elevation beam of the digital array antenna needs to cover 1.97°-21.80°. Based on the bistatic radar equation, the antenna gain requirement under target area coverage is calculated, and the target pattern of the digital array antenna can be obtained. Figure 6 As shown in the figure, the gain of the digital array antenna at the maximum detection distance is 32.8 dBi, which meets the radar gain requirement for maximum distance detection.
[0044] Step 2: Based on the technical requirements, a digital array antenna with full digital azimuth and beamforming in elevation is designed, and a genetic algorithm is used to optimize the unit amplitude and phase of the digital array antenna. The digital array antenna includes a 96-unit full digital architecture in azimuth and a 10-unit series-fed beamforming array in elevation. Early warning radar antennas usually use cosecant square beamforming. When the target moves at a constant height within the antenna beam, the echo signal received by the radar remains basically constant. The cosecant square function fitting result of the target pattern of the digital array antenna is shown in the figure below. Figure 5 As shown by the dotted line in the middle. According to the fitting results, the objective function is constructed:
[0045] (4)
[0046] Where θ is the elevation angle; SLL is the sidelobe level; θ0~θ min is the digital array antenna beam pointing; θ min ~θmax The beamforming angle of the digital array antenna.
[0047] According to the calculation results in step 1, θ0 is 1.97°, θ min is 10°, θ max is 21.80°. The objective function curve is as follows Figure 7 As shown in the figure, the dotted line is the objective function and the solid line is the synthesis result. Considering the requirements of spatial coverage and lightweight and low power design, 10 array elements are fed in series in the elevation direction to form a residual square beam. The genetic algorithm is used to perform array synthesis on the amplitude and phase of the 10 array elements. The shaping result meets the objective function of 1.97°-21.80° beam pointing and meets the -30 dB sidelobe level design. After array synthesis, the amplitude and phase values of the 10 array elements are shown in Figure 1. Figure 8 and Figure 9 .
[0048] In order to achieve the detection power of the stratospheric airship-borne radar, the digital array antenna must meet the gain requirement of 32.8 dBi. According to the relationship between antenna aperture and antenna gain:
[0049] (5)
[0050] Among them, G r is the digital array antenna gain, A is the digital array antenna aperture, is the wavelength corresponding to the radar operating frequency.
[0051] The digital array antenna utilizes a 10-element shaped array in elevation and 96 elements in azimuth, forming a 10×96 large-scale digital array antenna. This ensures the detection power required by stratospheric airship-borne radars. This digital array antenna utilizes a 96-channel all-digital architecture in azimuth, enabling ±60° beam scanning. It offers simultaneous multi-beam capability and adaptive anti-interference capabilities. In the direction of interference, it can achieve a typical null depth greater than -30 dB.
[0052] Assuming that the digital array antenna has two beams pointing at -30° and 30° respectively, and the sidelobe level is required to be less than -25 dB, the optimized radiation pattern can be obtained by optimizing the antenna unit amplitude and phase using a genetic algorithm. Figure 10 The dual-beam radiation pattern of the digital array antenna is given. The objective function is the dotted line, and the radiation pattern after genetic algorithm optimization is the solid line. The two beams point to -30° and 30° respectively, and the sidelobe level is less than -25 dB.
[0053] Assuming the interference direction is 21.5° to 25.5°, the required null depth is -40 dB and the sidelobe level is -25 dB. Figure 11The adaptive interference suppression pattern of the digital array antenna is shown. The dashed line represents the objective function, the solid line represents the pattern after amplitude and phase optimization using a genetic algorithm, and the gray area represents the null region. It can be seen that when the interference direction is between 21.5° and 25.5°, the digital array antenna can form a null with a depth of -40 dB, but the sidelobe level rises to -21.9 dB.
[0054] From the above discussion, it can be seen that the digital array antenna has the ability of beam scanning and adaptive interference suppression, which can meet the large-scale and long-distance detection requirements of stratospheric airship radar. In order to verify the effectiveness of the digital array antenna design, the digital array antenna was processed and tested, and the test results are as follows: Figure 12 The digital array antenna's azimuth pattern is generally consistent with the simulation results, and its elevation pattern exhibits good shaping characteristics. However, its beam pointing differs from the simulation results, and there is a pattern lift at -19°. This is due to the immature processing technology used in the ultimate lightweight design, resulting in large errors in the shaping network, which in turn affects the azimuth pattern shaping results.
[0055] On the other hand, the present invention provides a device for designing a large-scale digital array antenna for a stratospheric airship-borne radar, which includes modules capable of implementing the various steps of the aforementioned method, specifically including:
[0056] A calculation module is used to calculate the technical requirements of the array antenna based on the stratospheric airship platform parameters and radar detection requirements;
[0057] The output module is used to design a digital array antenna that is fully digital in azimuth and beam-forming in elevation according to the technical requirements, and to optimize the element amplitude and phase of the digital array antenna using a genetic algorithm; the digital array antenna includes a 96-element fully digital architecture in azimuth and a 10-element series-fed beamforming array in elevation.
[0058] In a third aspect, the present invention provides an electronic device comprising: one or more processors; and a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned method for designing a large-scale digital array antenna for a stratospheric airship-borne radar.
[0059] In a fourth aspect, the present invention provides a computer-readable storage medium having executable instructions stored thereon, which, when executed by a processor, enables the processor to implement the aforementioned method for designing a large-scale digital array antenna for a stratospheric airship-borne radar.
[0060] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for designing a large-scale digital array antenna for a stratospheric airship-borne radar, characterized in that: The design method includes: Step 1: Calculate the technical requirements of the array antenna based on the stratospheric airship platform parameters and radar detection requirements; Step 2: Based on the technical requirements, design a digital array antenna that is fully digital in azimuth and beam-forming in elevation, and use a genetic algorithm to optimize the unit amplitude and phase of the digital array antenna; the digital array antenna includes a 96-unit fully digital architecture in azimuth and a 10-unit series-fed beamforming array in elevation.
2. The method for designing a large-scale digital array antenna for a stratospheric airship-borne radar according to claim 1, characterized in that: The technical requirements include antenna gain, beam coverage and detection range.
3. The method for designing a large-scale digital array antenna for a stratospheric airship-borne radar according to claim 2, characterized in that: The technical requirements include that the digital array antenna has a maximum detection range of 580 km, a gain greater than 32.8 dBi, and an elevation beam coverage range of 1.97°-21.80°.
4. The method for designing a large-scale digital array antenna for a stratospheric airship-borne radar according to claim 2, characterized in that: The technical requirements are determined according to the bistatic radar equation, where the detection probability P d , signal-to-noise ratio (SNR) and false alarm probability The relationship between them is: （3） Wherein, Q is the Marcum Q function, and the signal-to-noise ratio (SNR) is associated with the antenna gain and the detection distance.
5. The method for designing a large-scale digital array antenna for a stratospheric airship-borne radar according to claim 4, characterized in that: The signal-to-noise ratio SNR is expressed as: （2） Among them, SNR is the signal-to-noise ratio, P av is the emission power of the radiation source, G t is the radiation source antenna gain, G r is the digital array antenna gain, λ is the wavelength corresponding to the radar operating frequency, σ is the target radar scattering cross section; t is the radar illumination time, R t is the distance from the radiation source to the target area, R r is the radar range, k is the Boltzmann constant, T0 is the effective noise temperature, F is the noise coefficient, L s Radar loss.
6. The method for designing a large-scale digital array antenna for a stratospheric airship-borne radar according to claim 1, characterized in that: In step 2, the target pattern of the digital array antenna is fitted using cosecant square shaping to construct an objective function: （4） Where θ is the elevation angle; SLL is the sidelobe level, θ0~θ min is the digital array antenna beam pointing, θ min ~θ max The beamforming angle of the digital array antenna.
7. The method for designing a large-scale digital array antenna for a stratospheric airship-borne radar according to claim 6, characterized in that: According to the technical requirements, the parameters of the objective function are calculated as follows: θ0 is 1.97°, θ min is 10°, θ max It is 21.80°.
8. A large-scale digital array antenna design device for stratospheric airship-borne radar, characterized in that: include: A calculation module is used to calculate the technical requirements of the array antenna based on the stratospheric airship platform parameters and radar detection requirements; The output module is used to design a digital array antenna that is fully digital in azimuth and beam-forming in elevation according to the technical requirements, and to optimize the element amplitude and phase of the digital array antenna using a genetic algorithm; the digital array antenna includes a 96-element fully digital architecture in azimuth and a 10-element series-fed beamforming array in elevation.
9. An electronic device, characterized in that: include: one or more processors; a memory for storing one or more programs; When one or more programs are executed by the one or more processors, the one or more processors implement the method for designing a large-scale digital array antenna for a stratospheric airship-borne radar as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that Executable instructions are stored thereon, and when the instructions are executed by a processor, the processor can implement a large-scale digital array antenna design method for a stratospheric airship-borne radar according to any one of claims 1 to 7.