A full-space staring digital array radar system

Abstract

This invention provides a full-space staring digital array radar system. The system includes a digital antenna array, a radio frequency front-end, a beamforming network, and a control and processing center. The digital antenna array adopts a structure combining hemispherical and cylindrical surfaces, and the height of the cylindrical array and the radius of the hemispherical array must satisfy a certain relationship. During transmission, the radar controls the beamforming network and corresponding antenna elements of each subarray to transmit signals through the control and processing center. During reception, the radar echo is received by the receiving elements of the digital antenna array to form multiple echo signals, which are then processed by the control and processing center for target detection and tracking. The full-space staring digital array radar system of this invention has superior multi-target and full-space simultaneous surveillance capabilities, improving the radar's early warning efficiency across the entire airspace. It can simultaneously track multiple targets from various airspace angles, providing strong real-time full-space surveillance capabilities.

Description

Technical Field

[0001] This invention relates to the field of radar technology, and in particular to a full-space staring digital array radar system. Background Technology

[0002] With the rapid development of technologies such as drone swarms and the increasing demands for various security measures, the types and numbers of targets that radar needs to monitor are constantly increasing, making detection tasks more and more complex. Radar systems need to have the ability to detect wide-area, multi-target targets in real time.

[0003] Currently, most existing radar systems use planar arrays or parabolic antennas, which can only achieve time-division monitoring of multiple targets within a certain airspace. If the targets are distributed throughout the entire airspace surrounding the radar system, traditional radar cannot simultaneously track and measure multiple targets within the entire airspace.

[0004] Existing planar phased array radar antennas mostly employ a combination of mechanical and electronic scanning to achieve time-division scanning of azimuth and part of elevation angles. When tracking and measuring multiple targets, the radar system suffers from low data rates and cannot achieve coverage of the airspace at large elevation angles. To achieve real-time scanning capability across the entire airspace, the optimal approach is to use a hemispherical antenna array. Hemispherical antenna arrays have high element utilization, ensuring isotropic uniformity of antenna radiation across the entire airspace. However, a problem with hemispherical antenna arrays is that their effective radiating area changes as the elevation scanning angle decreases. When the effective area exceeds a certain value, it will decrease, and at the limiting scan angle of 90°, its effective radiation area will decrease to half. To ensure the radiation uniformity of the digital antenna array in the elevation direction, the spherical surface can be extended downwards, thereby keeping the effective area of ​​the antenna constant throughout the scanning process.

[0005] Therefore, researching and designing a multi-target radar detection system covering the entire airspace is of great application value for solving the problems of monitoring, measuring and controlling multiple targets across the entire airspace. Summary of the Invention

[0006] Embodiments of the present invention provide a full-airspace staring digital array radar system to effectively improve the radar's early warning and surveillance efficiency over the entire airspace.

[0007] To achieve the above objectives, the present invention adopts the following technical solution.

[0008] A full-space staring digital array radar system includes: a digital antenna array, a radio frequency front-end, a beamforming network, and a control and processing center. The digital antenna array adopts a structure combining hemispherical and cylindrical surfaces, and the height of the cylindrical array and the radius of the hemispherical array must satisfy a certain relationship.

[0009] During transmission, the radar controls the beamforming network and corresponding antenna elements of each subarray to transmit signals through the control and processing center. During reception, the radar echo is received by each receiving element of the digital antenna array to form multiple echo signals, which are then processed by the control and processing center for target detection and tracking.

[0010] Preferably, during beam scanning, the all-space staring digital array radar system has two beam scanning modes: omnidirectional beam transmission and narrow beam reception, and narrow beam transmission and narrow beam reception. The omnidirectional beam transmission and narrow beam reception mode is used to complete the search and early warning of targets in the entire airspace, while the narrow beam transmission and narrow beam reception mode is used for long-range target detection and tracking.

[0011] Preferably, when the system operates in omnidirectional beam transmitting and narrow beam receiving mode, each antenna element on the radar array acts as an independent transmitting unit, forming an omnidirectional transmitting beam with uniform gain in space. During reception, each antenna receiving unit receives reflected signals from space and forms multiple high-gain narrow beams through beamforming and signal processing techniques, enabling simultaneous search and detection of multiple targets in the entire airspace.

[0012] Preferably, when the system operates in narrow beam transmit and narrow beam receive mode, each antenna element on the radar array is composed of several subarrays through a feeding network. Each subarray forms a narrow, high-gain transmit and receive beam in the corresponding direction by transmitting beam combining, thereby enabling simultaneous long-range detection and tracking of multiple airspace targets.

[0013] Preferably, the radius of the hemispherical antenna array and the cylindrical antenna array in the digital antenna array is R. a The height of the cylindrical antenna array is The antenna array of the digital antenna array adopts a cylindrical surface with a cross-section equal to the diameter of the sphere, extending downwards. The entire antenna array is in the form of a hemispherical plus cylindrical surface. At low elevation angles, beamforming is achieved by adding some cylindrical array elements to realize the uniformity of gain of the entire antenna array when tracking the target in the entire airspace.

[0014] Preferably, the beamforming network includes a subarray-level beamforming network and an inter-subarray beamforming network. Amplitude and phase weighting at the array element level is performed in the subarray-level beamforming network processor. The subarray-level beamforming processor realizes the primary digital beamforming of the corresponding beam, which is then converted into an optical signal via electro-optic conversion and transmitted to the inter-subarray beamforming processor via optical fiber. The inter-subarray beamforming processor is used to perform secondary beamforming on the beamforming signals output by each subarray to form multiple high-gain narrow beams.

[0015] As can be seen from the technical solutions provided by the embodiments of the present invention described above, the all-space staring digital array radar system of the present invention has a superior ability to monitor multiple targets and the entire airspace simultaneously, which can improve the radar's early warning and surveillance efficiency for the entire airspace. Because the all-space staring digital array radar can continuously and in real-time detect the entire airspace, it can simultaneously track multiple targets at various airspace angles, has a high system data rate, and strong real-time all-space surveillance capability.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the array surface model in an all-space staring digital array radar antenna provided in an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of an all-space staring digital array radar with omnidirectional beam transmission and narrow beam reception mode provided in an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of a narrow-beam transmission and narrow-beam reception mode for an all-space staring digital array radar provided in an embodiment of the present invention;

[0021] Figure 4 A schematic diagram illustrating the basic structure and working principle of an all-space staring digital array radar system provided in this embodiment of the invention;

[0022] Figure 5 This is a schematic diagram illustrating the beamforming principle of an all-space staring digital array radar provided in an embodiment of the present invention. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or couplings. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0025] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0026] To facilitate understanding of the embodiments of the present invention, the following will provide further explanation and description with reference to the accompanying drawings and several specific embodiments. These embodiments do not constitute a limitation on the embodiments of the present invention.

[0027] Full-space detection refers to the ability to monitor target signals within an azimuth range of 0–360° and an elevation range of 0–90°. Multi-target surveillance refers to the simultaneous detection of multiple targets in different positions and states. Unlike traditional planar phased array radars, which use time-division multiplexing to form high-gain, narrow-beam scanning with a fixed direction in space, full-space staring radars employ a fully digital array. The transmitted signal can use a low-gain, wide-beam transmission to cover the entire airspace. During reception, beamforming networks and signal processing techniques are used to form multiple beams simultaneously, significantly reducing the scanning time across the entire detection airspace and improving the monitoring and tracking performance of multiple targets, thus achieving rapid, real-time scanning across the entire airspace.

[0028] A schematic diagram of the array surface model in a full-space staring digital antenna array provided in this embodiment of the invention is shown below. Figure 1 As shown, the radius of the hemispherical antenna array and the cylindrical antenna array is R. a The height of the cylindrical antenna array is The antenna array in the all-space staring digital array radar system provided in this invention adopts a cylindrical shape with a cross-section equal to the diameter of a sphere, extending downwards. The entire antenna array is a combination of a hemispherical and cylindrical surface. This array configuration ensures the azimuth radiation symmetry of the antenna. At low elevation angles, beamforming by incorporating some cylindrical array elements can compensate for the gain loss of the antenna at low elevation angles, thereby ensuring the gain uniformity of the entire antenna array when tracking targets in the entire airspace.

[0029] During beam scanning, the radar has two beam scanning modes: omnidirectional beam transmission with narrow beam reception and narrow beam transmission with narrow beam reception. Omnidirectional beam transmission with narrow beam reception can be used for searching and early warning of targets across the entire airspace, while narrow beam transmission with narrow beam reception can be used for detecting and tracking long-range targets.

[0030] Figure 2 This diagram illustrates an omnidirectional beam-transmitting and narrow-beam-receiving mode for an all-space staring digital array radar, as provided in an embodiment of the present invention. When the system operates in omnidirectional beam-transmitting and narrow-beam-receiving mode, each antenna element on the radar array acts as an independent transmitting element, forming an omnidirectional transmitting beam with uniform gain in space. During reception, each antenna receiving element receives reflected signals from space, and multiple high-gain narrow beams are simultaneously formed through beamforming and signal processing techniques, thereby enabling simultaneous search and detection of multiple targets in the entire airspace.

[0031] Figure 3 This is a schematic diagram of a narrow-beam transmit and narrow-beam receive mode for a full-space staring digital array radar provided in an embodiment of the present invention. When the system operates in the narrow-beam transmit and narrow-beam receive mode, the antenna elements on the radar array are connected by a feeding network to form several subarrays. Each subarray forms a narrow, high-gain transmit and receive beam in the corresponding direction through transmit beam combining, enabling simultaneous long-range detection and tracking of multiple airspace targets.

[0032] A schematic diagram illustrating the basic structure and working principle of an all-space staring digital antenna array radar system provided in this invention is shown below. Figure 4 As shown, the system comprises four subsystems: a digital antenna array, a radio frequency front-end, a beamforming network, and a control and processing center. During transmission, the radar, through the control and processing center, controls the beamforming networks and corresponding antenna elements of each subarray to transmit signals. After up-conversion, each antenna element forms a corresponding coverage beam in space. During reception, the radar echo is received by the receiving elements of the antenna array, forming multiple analog echo signals. After down-conversion, amplification, and AD sampling, these are converted into multiple baseband echo signals. After amplitude and phase error compensation and beamforming, multiple beam signals can be output. These signals are then processed by the control and processing center for target detection and tracking, enabling target monitoring and measurement within the corresponding airspace.

[0033] The digital antenna array subsystem consists of several receiving elements, transmitting elements, and transceiver components (T / R), integrating the transmission and reception functions of radio frequency signals in traditional radar systems.

[0034] The RF front-end subsystem includes up / down converters, amplifiers, amplitude and phase error correction (A / D) systems, and analog-to-analog converters (AD / DA) systems. Up / down conversion enables the conversion between RF and baseband signals. Amplifiers and AD systems convert received analog signals into digital signals. Amplitude and phase error correction compensates for amplitude and phase inconsistencies in each channel. Before the radar is put into operation, the compensation factors for each antenna element are generated by testing the amplitude and phase characteristics of each receiving channel using a reference signal. These correction factors are then used to compensate for the inconsistencies in each channel. The compensated digital signal is then serially transmitted and output to the downstream subarray beamforming network processing section.

[0035] The beamforming network is used to form and control the transmit and receive beams. To reduce the large number of cables and connectors required by massive MIMO (Massively Multi-Area Transceiver Units), and to lower system complexity and the amount of data processed, the all-space staring digital array radar employs a hierarchical beamforming approach. The beamforming network consists of two parts: a subarray-level beamforming network and an inter-subarray beamforming network. Amplitude and phase weighting at the element level is performed in the subarray-level beamforming network processor. Primary digital beamforming (DBF) of the corresponding beam is achieved in the subarray-level beamforming processor, converted into optical signals via electro-optical conversion, and transmitted to the inter-subarray beamforming processor via optical fiber. The inter-subarray beamforming processor is responsible for secondary beamforming of the beamforming signals output from each subarray, ultimately forming multiple high-gain narrow beams. By employing a hierarchical beamforming network, the number of data transmission cables and the amount of data processed by the system can be significantly reduced. Simultaneously, it ensures good scalability and reconfigurability for implementing different array sizes and functions.

[0036] The control and processing center mainly controls the working status and beam scanning mode of the radar system, as well as performs processing functions such as target detection, parameter measurement, tracking and identification of received signals. These processing functions are similar to those of traditional radar processing methods, and will not be described in detail in this solution.

[0037] A schematic diagram of the beamforming principle of an all-space staring digital array radar provided in this embodiment of the invention is shown below. Figure 5As shown. The all-space staring digital array radar system of this invention uses a beamforming network to control the amplitude and phase of the radiated signals of each antenna element, thereby achieving beamforming and coverage of multiple antenna array elements in the desired direction.

[0038] Assume the antenna transceiver elements are uniformly arranged on the hemispherical and cylindrical surfaces. The position vector of the nth element relative to the phase reference point is (x... n ,y n ,z n ), distance is Based on the transformation relationship between cylindrical coordinates and rectangular coordinates, we have:

[0039]

[0040] Assuming its radiation pattern is The feed amplitude and phase of the antenna element are A n and η n When the radar operates in omnidirectional beam transmission and narrow beam reception mode, the total radiation pattern synthesized in space by the entire spherical array can be represented as:

[0041]

[0042] Where N is the total number of effective radiating elements in the entire antenna array, and λ is the operating wavelength of the radar system.

[0043] During reception, a two-stage beamforming method is employed to achieve reception of multiple spatial high-gain narrow beams. Assume the entire antenna array is divided into K subarrays, with each element in each subarray receiving the electromagnetic wave signal reflected from the target. During receive beamforming, firstly, all receiving antenna elements within a subarray perform subarray beamforming, and then multiple receiving subarrays undergo a second-stage beamforming process between subarrays. Assume the spatial position of the m-th target is... If the k-th subarray needs to be oriented... If beamforming is performed on the array, the beam synthesis model within the subarray can be expressed as:

[0044]

[0045] Where N k Let n be the number of antenna elements in the k-th subarray. This refers to the echo signal received by the nth receiving antenna element in the receiving subarray. and This is the amplitude and phase weighting factor for the receiving antenna element. It can be represented as:

[0046]

[0047] in, Let be the coordinate position of the nth antenna element in the kth subarray. After beamforming processing of each subarray in this direction, beamforming is performed between all K subarrays of the entire antenna array in this direction. The beamforming model between subarrays can be expressed as:

[0048]

[0049] In the above formula, and These are the amplitude and phase weighting factors of the synthesized signal of the k-th subarray, respectively. By performing simultaneous multi-beam synthesis in the above manner, multiple high-gain narrow receiving beams can be formed throughout the entire space, enabling simultaneous coverage and detection of multiple distributed targets in the entire airspace.

[0050] Similarly, when the radar operates in narrow beam transmit and narrow beam receive mode, its beamforming control method is similar to the receiving beamforming method described above.

[0051] In summary, this invention addresses the need for simultaneous detection of multiple targets across the entire airspace. This patent proposes a full-airspace staring digital array radar system. Based on an antenna array combining hemispherical and cylindrical surfaces, it effectively solves problems such as low scanning data rate and gain loss with scanning angle in planar phased arrays, enabling simultaneous coverage and detection of multiple targets in the airspace. Furthermore, through hierarchical beamforming processing, it reduces system structural complexity and development costs, effectively decreasing the amount of data transmitted and processed, while improving system scalability and reconfigurability. The technical method of this invention has high application value in real-time multi-target detection across the entire airspace and represents an important future development direction for phased array radar.

[0052] The all-space staring digital array radar system of this invention has superior multi-target and all-space simultaneous surveillance capabilities, improving the radar's early warning and surveillance efficiency across the entire airspace. Because the all-space staring digital array radar can continuously and in real-time detect the entire airspace, it can simultaneously track multiple targets from various airspace angles, resulting in a high system data rate and strong real-time all-space surveillance capabilities.

[0053] The all-space staring digital array radar system of this invention has high anti-interception capability, improving the battlefield survivability of the radar system. The all-space staring digital array radar uses an omnidirectional transmitting antenna with low transmission gain, making it difficult to intercept and highly concealed, effectively improving the battlefield survivability of the equipment.

[0054] The all-space staring digital array radar system of this invention has a simple structure and strong upgrade and expansion capabilities. Since the transmitting end only uses an omnidirectional transmitting antenna, the structure is simple and easy to implement. At the same time, both the transceiver units use digital arrays and beamforming networks for control, which improves the system's upgrade and expansion capabilities.

[0055] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of one embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing the present invention.

[0056] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

[0057] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for apparatus or system embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. The apparatus and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0058] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A full-space staring digital array radar system, characterized in that, include: The system includes a digital antenna array, a radio frequency front-end, a beamforming network, and a control and processing center. The digital antenna array adopts a structure combining hemispherical and cylindrical surfaces, and the height of the cylindrical surface and the radius of the hemispherical surface must satisfy a certain relationship. During transmission, the radar controls the beamforming network and corresponding antenna elements of each subarray to transmit signals through the control and processing center; during reception, the radar echo is received by each receiving element of the digital antenna array to form multiple echo signals, which are then processed by the control and processing center for target detection and tracking. The radius dimensions of the hemispherical antenna array and the cylindrical antenna array in the digital antenna array are: The height of the cylindrical antenna array is The antenna array of the digital antenna array adopts a cylindrical surface with a cross section equal to the diameter of the sphere, extending downwards. The entire antenna array is in the form of a hemispherical plus cylindrical surface. At low elevation angles, beamforming is achieved by adding some cylindrical array elements to realize the uniformity of gain of the entire antenna array when tracking the target in the entire airspace.

2. The system according to claim 1, characterized in that, When performing beam scanning, the all-space staring digital array radar system has two beam scanning modes: omnidirectional beam transmission and narrow beam reception, and narrow beam transmission and narrow beam reception. Omnidirectional beam transmission and narrow beam reception are used to complete the search and early warning of targets in the entire airspace, while narrow beam transmission and narrow beam reception are used for long-range target detection and tracking.

3. The system according to claim 2, characterized in that, When the system operates in omnidirectional beam transmit and narrow beam receive mode, each antenna element on the radar array acts as an independent transmitting unit, forming an omnidirectional transmit beam with uniform gain in space. During reception, each antenna receiving unit receives reflected signals from space and forms multiple high-gain narrow beams through beamforming and signal processing techniques, enabling simultaneous search and detection of multiple targets in the entire airspace.

4. The system according to claim 2, characterized in that, When the system operates in narrow beam transmit and narrow beam receive mode, the antenna elements on the radar array are connected by a power supply network to form several subarrays. Each subarray forms a narrow, high-gain transmit and receive beam in the corresponding direction by transmitting beam combining, enabling simultaneous long-range detection and tracking of multiple airspace targets.

5. The system according to any one of claims 1 to 4, characterized in that, The beamforming network includes a subarray-level beamforming network and an inter-subarray beamforming network. Amplitude and phase weighting at the array element level is performed in the subarray-level beamforming network processor. The subarray-level beamforming processor realizes the primary digital beamforming of the corresponding beam, which is then converted into an optical signal via electro-optic conversion and transmitted to the inter-subarray beamforming processor via optical fiber. The inter-subarray beamforming processor is used to perform secondary beamforming on the beamforming signals output by each subarray to form multiple high-gain narrow beams.

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