24GHz rotation phased array millimeter wave radar system and device

Abstract

According to the 24GHz rotary phased array millimeter wave radar system and device, a phased array beam forming working mode is introduced, a plurality of transmitting antennas are synthesized into a highly-directive transmitting beam with highly concentrated energy for electronic scanning, and compared with a traditional time-sharing working mode, the transmitting power is remarkably improved, and the transmission efficiency is greatly improved. The detection capability of weak and small targets is improved; meanwhile, a high-efficiency mixed scanning mechanism is constructed by combining constant-speed continuous mechanical rotation with electronic scanning in a frame period, the mechanism realizes full-coverage scanning in an azimuth dimension through mechanical rotation, and spherical scanning is jointly formed by executing multiple pitching dimension electronic scanning in different directions in each preset frame period. And the space coverage range of the radar is greatly improved. Besides, through the adaptation of the frame period duration and the mechanical rotating speed, the synchronization of electronic scanning, data acquisition and processing flows is ensured, and guarantee is provided for continuously and reliably outputting multi-dimensional information such as the distance, the speed and the angle of a detected target.

Description

Technical Field

[0001] This invention relates to the field of millimeter-wave radar, and in particular to a 24GHz rotating phased array millimeter-wave radar system and equipment. Background Technology

[0002] In the field of drone perception and obstacle avoidance, 24GHz millimeter-wave radar is widely used due to its small size, light weight, low cost, and good environmental adaptability (such as the ability to penetrate fog and dust). However, as drone application scenarios become more complex and sophisticated, existing radar systems face severe challenges and urgently need to improve their detection capabilities for small targets such as utility poles and cable-stayed bridges.

[0003] Currently, monolithic integrated millimeter-wave radar chips are limited by physical size and power consumption, resulting in low single-channel transmit power. When detecting small targets, the echo signal is extremely weak, and the system signal-to-noise ratio is severely insufficient, leading to an effective detection range typically only a few meters or tens of meters. For high-speed drones, this distance is insufficient to provide enough reaction time for obstacle avoidance, posing a significant safety hazard. Furthermore, monolithic radars usually have a limited number of physical antenna channels and low angular resolution. This low resolution makes it difficult for the radar to effectively distinguish multiple adjacent small targets in space (such as multiple parallel power lines), leading to missed target detection or misclassification of multiple nearby targets as a single large target, resulting in obstacle avoidance decision errors.

[0004] To improve performance, the industry has attempted to use TDM-MIMO technology to enhance angular resolution through virtual channels. However, due to the time-division multiplexing principle of its transmitting antennas, this technology sacrifices the power-aperture product at the transmitting end, thus failing to fundamentally solve the core problems of insufficient transmission power and short detection range for weak targets. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a 24GHz rotating phased array millimeter-wave radar system and equipment to solve the technical problems of insufficient transmission power and short detection range of weak targets in existing 24GHz millimeter-wave radars.

[0006] To achieve the above and other related objectives, this application provides a 24GHz rotating phased array millimeter-wave radar system, characterized by comprising: a mechanical rotating device; a radar front-end module fixed on the mechanical rotating device and rotating continuously at a uniform speed following the mechanical rotating device; wherein the radar front-end module includes: a transmitting antenna unit and a receiving antenna unit, the transmitting antenna unit operating in a phased array beamforming mode; the transmitting antenna unit and the receiving antenna unit performing multiple electronic scans pointing to different directions within each preset frame period to complete a corresponding frame of data sampling, the frame period duration being adapted to the rotational speed of the mechanical rotating device; and a control and signal processing module, the control and signal processing module receiving and processing one frame of sampled data in each frame period and outputting multidimensional information of the detected target.

[0007] In some embodiments of the first aspect of this application, the transmitting antenna unit includes: a transmitting antenna unit chip, and a plurality of transmitting antennas disposed on the transmitting antenna unit chip, the plurality of transmitting antennas being linearly arranged on the transmitting antenna unit chip according to a preset first antenna spacing and a first antenna arrangement direction; the transceiver antenna unit includes: a transceiver antenna unit chip, and a plurality of receiving antennas disposed on the transceiver antenna unit chip, the plurality of receiving antennas being linearly arranged on the transceiver antenna unit chip according to a preset second antenna spacing and a second antenna arrangement direction.

[0008] In some embodiments of the first aspect of this application, the transceiver antenna unit chip is connected to the transmit antenna unit chip, and the transceiver antenna unit chip is used to provide a radio frequency signal source for the transmit antenna unit chip.

[0009] In some embodiments of the first aspect of this application, the electronic scanning plane corresponding to the multiple electronic scans pointing to different locations is perpendicular to the rotation plane of the mechanical rotating device; the transmitted beam synthesized by the multiple transmitting antennas includes: a first 3dB beamwidth in the electronic scanning plane, and a second 3dB beamwidth in a measurement plane perpendicular to the electronic scanning plane.

[0010] In some embodiments of the first aspect of this application, the number of transmitting antennas is the same as the number of receiving antennas.

[0011] In some embodiments of the first aspect of this application, the plurality of transmitting antennas are arranged with a first antenna spacing of λ / 2, and the plurality of receiving antennas are arranged with a second antenna spacing of λ / 2.

[0012] In some embodiments of the first aspect of this application, the transmitting antenna unit and the transceiver antenna unit perform multiple electronic scans pointing to different directions within a preset frame period to complete a corresponding frame data sampling, including: within each frame period, the transmitting antenna unit sequentially synthesizes a preset number of transmitting beams by changing the phase difference between the signals of adjacent transmitting antennas, wherein the pointing angle interval between two adjacent transmitting beams is not greater than half of the width of the first 3dB beam; the transceiver antenna unit completes multiple data sampling accordingly.

[0013] In some embodiments of the first aspect of this application, the rotation angle of the mechanical rotating device during each frame period is no greater than the second 3dB beamwidth.

[0014] In some embodiments of the first aspect of this application, the control and signal processing module receives and processes one frame of sampled data for each frame period and outputs multidimensional information of the detected target, including: performing a distance-dimensional fast Fourier transform on the sampled data to parse the target's distance information; performing a velocity-dimensional fast Fourier transform on the sampled data to parse the target's velocity information; and performing angle-dimensional processing on the sampled data to parse the target's angle information.

[0015] To achieve the above and other related objectives, a second aspect of this application provides a 24GHz rotating phased array millimeter-wave radar device, comprising: the aforementioned 24GHz rotating phased array millimeter-wave radar system.

[0016] As described above, the 24GHz rotating phased array millimeter-wave radar system, method, and device of this application have the following beneficial effects: By introducing a phased array beamforming operating mode, this invention combines multiple transmitting antennas into a highly concentrated, strongly directional transmitting beam for electronic scanning by controlling the phase of the transmitting antenna elements. Compared to the traditional time-division multiplexing operating mode, the transmitting power is significantly improved, enhancing the detection capability and maximum detection range for weak targets. Simultaneously, by combining uniform, continuous mechanical rotation with electronic scanning within a frame period, a highly efficient hybrid scanning mechanism is constructed. This mechanism achieves full azimuth coverage scanning through mechanical rotation and performs multiple elevation scans in different directions within each preset frame period, collectively forming a spherical scan, greatly improving the radar's spatial coverage. Furthermore, by adapting the frame period duration to the mechanical rotation speed, the synchronization of electronic scanning, data acquisition, and processing is ensured, guaranteeing the continuous and reliable output of multi-dimensional information such as the range, velocity, and angle of the detected target. Attached Figure Description

[0017] Figure 1 The diagram shown is a structural schematic of a 24GHz rotating phased array millimeter-wave radar system according to an embodiment of the present invention.

[0018] Figure 2 The flowchart shown is a 24GHz rotating phased array millimeter-wave radar system according to an embodiment of the present invention.

[0019] Figure 3 The diagram shown is a structural schematic of a 24GHz rotating phased array millimeter-wave radar system according to an embodiment of the present invention, with the transmitted wave velocity in the electronic scanning plane.

[0020] Figure 4 The diagram shown is a structural schematic of the transmitted wave velocity in the measurement plane of a 24GHz rotating phased array millimeter-wave radar system according to an embodiment of the present invention.

[0021] Figure 5 The flowchart shown is a 24GHz rotating phased array millimeter-wave radar system according to an embodiment of the present invention.

[0022] Figure 6 The diagram shown is a data processing flowchart of a 24GHz rotating phased array millimeter-wave radar system according to an embodiment of the present invention. Detailed Implementation

[0023] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0024] It should be noted that in the following description, reference is made to the accompanying drawings, which illustrate several embodiments of this application. It should be understood that other embodiments may also be used, and changes in mechanical composition, structure, electrical system, and operation may be made without departing from the spirit and scope of this application. The following detailed description should not be considered limiting, and the scope of the embodiments of this application is defined only by the claims of the published patent. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application. Spatially related terms, such as “upper,” “lower,” “left,” “right,” “below,” “below,” “lower part,” “above,” “upper part,” etc., may be used herein to illustrate the relationship between one element or feature shown in the figures and another element or feature.

[0025] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," and "holding" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data used can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising,” “including,” indicate the presence of the stated features, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, operations, elements, components, items, kinds, and / or groups. It should be further understood that the terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” An exception to this definition will only occur if the combination of elements, functions, or operations is inherently mutually exclusive in some way.

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the invention.

[0028] like Figure 1 The diagram shows a structural schematic of a 24GHz rotating phased array millimeter-wave radar system according to an embodiment of the present invention, including: a mechanical rotating device 10, a radar front-end module 11, and a control and signal processing module 12.

[0029] The mechanical rotating device 10 can drive the radar front-end module 11 to rotate stably and continuously at a uniform speed, providing a reliable scanning reference for the system.

[0030] The radar front-end module 11 is fixedly installed on the mechanical rotating device 10 and rotates synchronously under the drive of the mechanical rotating device 10. The radar front-end module 11 and the mechanical rotating device 10 together constitute the spatial scanning basis of the system.

[0031] like Figure 2 As shown, the radar front-end module 11 includes a transmitting antenna unit 112 and a transceiver antenna unit 111. The transmitting antenna unit 112 includes a transmitting antenna unit chip 1122 and multiple transmitting antennas 1121 disposed on the transmitting antenna unit chip 1122; the transceiver antenna unit 111 includes a transceiver antenna unit chip 1112 and multiple receiving antennas 1111 disposed on the transceiver antenna unit chip 1112.

[0032] On the transmitting antenna unit chip 1122, all transmitting antennas 1121 are arranged according to the first antenna spacing d1 and the first antenna arrangement direction A. Except for direction A, there are no transmitting antennas 1121 in other directions. On the receiving antenna unit chip 1112, all receiving antennas 1111 are arranged according to the second antenna spacing d2 and the second antenna arrangement direction B. Except for direction B, there are no receiving antennas 1111 in other directions.

[0033] In this arrangement, all transmitting antennas 1121 or all receiving antennas 1111 are arranged along a selected direction, which is called linear arrangement.

[0034] The transmitting antenna unit 112 operates in a phased array beamforming mode. In this mode, the multiple transmitting antennas 1121 do not work independently, but are controlled by the transmitting antenna unit chip 1122 to transmit signals synchronously as a whole. The transmitting antenna unit chip 1122 can precisely control the phase of the signal of each transmitting antenna 1121, so that the signals transmitted by all antennas interfere in space and are synthesized into a transmitting beam with a specific directionality.

[0035] Its working principle is that by pre-setting a fixed phase difference between adjacent transmitting antennas 1121, the signals emitted by all transmitting antennas 1121 are spatially superimposed in phase in a specific direction, synthesizing a highly concentrated directional transmitting beam, i.e., the main lobe; while in other directions, the signals are weakened by being out of phase.

[0036] The transmitting antenna unit 112 and the receiving antenna unit 111 operate cyclically based on a preset frame period. Within each frame period, in order to achieve n electronic scans, the transmitting antenna unit chip 1122 changes the phase difference between the signals of adjacent transmitting antennas 1121, so that multiple transmitting antennas 1121 sequentially synthesize n transmitting beams pointing to different directions.

[0037] When synthesizing a transmit beam pointing to a specific direction, the phase difference between the signals of adjacent transmit antennas of the multiple transmit antennas 1121 is a fixed value. The fixed This directly determines the pointing angle θ of the emitted beam within the electronic scanning plane. By setting this fixed phase difference value to... This allows control over the pointing angle of the transmitted beam within the electronic scanning plane. .

[0038] For each transmit beam synthesized based on a specific phase difference value, the transceiver antenna unit 111 performs a corresponding data sampling once. When all n phase difference values ​​corresponding to different directions have been traversed and all n corresponding data samplings have been completed, the data sampling task for the current frame period is considered complete. The set of n data samples obtained at this time constitutes a complete frame of sampled data.

[0039] It should be noted that the electronic scanning plane is determined by the physical arrangement of the multiple transmitting antennas 1121. When the transmitting antenna element 112 operates in phased array beamforming mode, the direction of the transmitted beam synthesized by the multiple transmitting antennas 1121 is constrained to vary within a plane that is parallel to the antenna arrangement direction and the maximum radiation direction of the transmitted beam, and includes both directions. This plane is the electronic scanning plane, and the scanning that occurs on this electronic scanning plane is called electronic scanning. Within the electronic scanning plane, the pointing angle θ of the transmitted beam is defined as follows: taking the normal direction of the plane where the multiple transmitting antennas 1121 are located as a reference, θ represents the angle between the maximum radiation direction of the transmitted beam and the normal direction. In addition, the number of sampling points is the same for each electronic scan, and within one frame period, multiple transmitted beams are transmitted continuously in time.

[0040] The control and signal processing module 12 includes a signaling control unit 122 and a signal processing unit 121. The signal processing unit 121 works in conjunction with the radar front-end module 11, operating cyclically based on a preset frame period. Within each frame period, it is responsible for processing and extracting information from a complete frame of sampled data. The signal processing unit 121 executes a series of signal processing algorithms to parse multi-dimensional information of the target from the complete frame of sampled data; this information includes at least the target distance, velocity, and angle, thereby achieving three-dimensional perception and target tracking of the target. The signaling control unit 122 sends control commands to control the various modules in the system to operate according to preset parameters.

[0041] It should be noted that the frame period duration is adapted to the rotational speed of the mechanical rotating device 10. This is to ensure that the radar front-end module 11 rotates through a fixed preset angle within each frame period. This adaptation is crucial for the coordinated operation of mechanical and electronic scanning, enabling the radar front-end module 11 to sample the target at fixed angular intervals during continuous uniform rotation. The start time of each frame period strictly corresponds to a unique and definite rotation angle, thus precisely synchronizing the rotation angle information of the mechanical rotating device 10 with the data frames sampled by the electronic scanning in time. Furthermore, the frame period duration must ensure that multiple electronic scans and the corresponding complete sampling data processing are completed within one frame period to ensure stable system operation.

[0042] The radar front-end module 11 also includes an analog-to-digital converter 113, which is used to convert the analog signal output by the transceiver antenna unit 111 into a digital signal in real time, and then transmit the digital signal to the control and signal processing module 12 for processing.

[0043] In one specific embodiment, phase control of each transmitting antenna 1121 is achieved by setting a reference antenna. Specifically, when synthesizing a transmitting beam pointing to a specific direction, the phase difference between each transmitting antenna 1121 and the reference antenna is... The formula relating this transmitted beam's pointing angle θ within the electronic scanning plane is as follows:

[0044]

[0045] in, λ represents the phase difference of each transmitting antenna relative to the reference antenna, λ is the wavelength of the transmitted signal, D is the distance of each transmitting antenna relative to the reference antenna, and θ is the pointing angle of the synthesized transmitted beam.

[0046] To facilitate understanding of this formula, assume that the transmitting antenna element 112 has m transmitting antennas 1121. For each desired pointing angle θ, the distance of each transmitting antenna relative to the reference antenna is... Substituting the values ​​into the formula above, calculate the phase difference of each transmitting antenna relative to the reference antenna. By controlling the phase configuration of each transmitting antenna accordingly, the synthesized transmitting beam can be directed at an angle θ in the electronic scanning plane.

[0047] It should be noted that for a transmit beam with a specific pointing angle θ, the phase difference between the signals from adjacent transmit antennas is essentially a fixed value, as mentioned above. .

[0048] In one embodiment, the radar front-end module 11 employs a functionally separated chip architecture. Specifically, the transceiver antenna unit chip 1112 is connected to the transmit antenna unit chip 1122. The transceiver antenna unit chip 1112 generates the radio frequency signal source required by the system; the transmit antenna unit chip 1122 acts as a beamformer, receiving the radio frequency signal source and driving multiple transmit antennas 1121 to synthesize a transmit beam with a specific pointing angle.

[0049] In one specific embodiment, the transmitting antenna unit chip 1122 may be a dedicated radio frequency front-end chip for beamforming. The number of its transmitting channels corresponds to the number of transmitting antennas 1121 in the transmitting antenna unit 112, and is used to independently drive each transmitting antenna 1121 and control the phase of its transmitted signal. For example, an MSRT1111 chip may be used.

[0050] The core function of this chip is to achieve multi-channel beamforming. It receives the radio frequency signal source provided by the transceiver antenna unit chip 1112, processes it into multiple parallel signals, then precisely controls the phase of each signal, and finally drives the transmitting antenna array to synthesize a transmitting beam with a specific direction.

[0051] In one embodiment, such as Figure 3 As shown, the transceiver antenna unit 111 includes a first transceiver antenna unit 114 and a second transceiver antenna unit 115. The first transceiver antenna unit 114 includes a first transceiver antenna unit chip 1142 and multiple receiving antennas 1141 disposed on the first transceiver antenna unit chip 1142. The multiple receiving antennas 1141 are arranged on the first transceiver antenna unit chip 1142 according to the second antenna spacing d2 and the second antenna arrangement direction B. The second transceiver antenna unit 115 includes a second transceiver antenna unit chip 1152 and multiple receiving antennas 1151 disposed on the second transceiver antenna unit chip 1152. The multiple receiving antennas 1151 are also arranged on the second transceiver antenna unit chip 1152 according to the second antenna spacing d2 and the second antenna arrangement direction B.

[0052] To construct the required number of receiving antennas 1111, a first transceiver antenna unit chip 1142 is cascaded as a slave chip and a second transceiver antenna unit chip 1152 is cascaded as a master chip. During cascading, the second transceiver antenna unit chip 1152 is connected to the first transceiver antenna unit chip 1142 via a first interface, and the distance between the receiving antenna 1151 at the beginning of the second transceiver antenna unit 1152 and the receiving antenna 1141 at the end of the first transceiver antenna unit 1142 is maintained at the second antenna spacing d2.

[0053] In addition, the second transceiver antenna unit chip 1152 also includes a second interface, through which the second transceiver antenna unit chip 1152 is connected to the transmitting antenna unit chip 1122, for providing a radio frequency signal source for the transmitting antenna unit chip 1122.

[0054] The analog-to-digital conversion unit 113 includes a first analog-to-digital conversion unit 1131 and a second analog-to-digital conversion unit 1132. The first analog-to-digital conversion unit 1131 is used to convert the analog signal output by the first transceiver antenna unit 114 into a digital signal in real time; the second analog-to-digital conversion unit 1132 is used to convert the analog signal output by the second transceiver antenna unit 115 into a digital signal in real time. All digital signals are synchronously transmitted to the control and signal processing module 12 for subsequent processing.

[0055] In one specific embodiment, to achieve the above-mentioned chip cascading function, the first and second transceiver antenna unit chips can be highly integrated millimeter-wave radar transceiver chips with cascading capabilities. For example, an SRK2402 chip can be used to construct the first transceiver antenna unit chip 1142 as a slave chip, and an SRK2401 chip can be used to construct the second transceiver antenna unit chip 1152 as a master chip.

[0056] This selection is primarily based on its cascading and synchronization capabilities. Cascading allows the receiving antennas of multiple chips to be integrated into a unified receiving antenna array with a larger aperture, providing the hardware foundation for subsequent angle estimation. Furthermore, this chip can provide the system with a stable and adjustable RF signal source.

[0057] In one embodiment, the electronic scanning plane is perpendicular to the rotation plane of the mechanical rotating device 10. In this configuration, the transmitted beam synthesized in each electronic scan includes a first 3dB beamwidth in the electronic scanning plane and a second 3dB beamwidth in a measurement plane perpendicular to the electronic scanning plane. Scanning in the electronic scanning plane is typically referred to as a pitch scan, and scanning in the measurement plane is typically referred to as an azimuth scan.

[0058] The 3dB beamwidth is an important parameter characterizing the width of the main lobe of the transmitted beam. It is defined as the angle between two directions in a plane containing the maximum radiation direction of the transmitted beam, where the radiated power density drops to half of the maximum main lobe value (i.e., -3dB). The narrower the 3dB beamwidth, the more concentrated the transmitted beam energy, the better the directivity, and the higher the corresponding angular resolution; conversely, the wider the 3dB beamwidth, the more dispersed the energy and the larger the coverage area.

[0059] To clearly illustrate the geometric relationship between the aforementioned angles and planes, we will now combine... Figure 4 and Figure 5 For example.

[0060] Figure 4 In the diagram, direction A represents the first antenna arrangement direction A of the multiple transmitting antennas 1121, direction C is the normal direction of the plane where the multiple transmitting antennas 1121 are located, and the electronic scanning plane 7 is a plane that is determined by direction A and the maximum radiation direction of the transmitted beam and includes both directions; the pointing angle 2 of the transmitted beam 1 is defined as the angle between the maximum radiation direction of the transmitted beam 1 and the normal direction C in the electronic scanning plane 7, and the first 3dB beamwidth 3 of the transmitted beam 1 is the 3dB beamwidth in the electronic scanning plane 7. Figure 5 In the measurement plane 8, the electronic scanning plane 7 is perpendicular to the measurement plane 8, and the second 3dB beamwidth 4 of the transmitted beam 1 is the 3dB beamwidth within the measurement plane 8.

[0061] In one embodiment, such as Figure 2 As shown, the number of transmitting antennas 1121 in the transmitting antenna unit 112 is the same as the number of receiving antennas 1111 in the transceiver antenna unit 111.

[0062] In one embodiment, such as Figure 2 As shown, the first antenna arrangement direction A of the transmitting antenna array and the second antenna arrangement direction B of the receiving antenna array are parallel to each other. When the transmitting antenna array and the receiving antenna array are arranged in the same direction, their corresponding electronic scanning planes tend to coincide or be parallel to each other in space, thereby ensuring a high degree of angular matching between the transmitting beam when it performs electronic scanning in the electronic scanning plane and the receiving beam when it performs beamforming.

[0063] It should be noted that the focus of this invention is on the collaborative working mechanism between the mechanical rotation device 10 and the electronic scanning when the transmitting antenna unit 112 operates in phased array beamforming mode. Its functionality does not entirely depend on the absolute symmetry of the number and arrangement direction of the transmitting and receiving antennas. For example, in other possible implementations, by adjusting the antenna spacing, optimizing the weighting coefficients of the beamforming algorithm, or employing a non-uniform array design, even when the number of antennas is not exactly the same or the arrangement direction has a certain angle, the technical effects described in this invention can still be achieved to a certain extent through system calibration and algorithm compensation.

[0064] In one embodiment, the multiple transmitting antennas 1121 are arranged with a first antenna spacing d1 that is no greater than half (λ / 2) of the operating wavelength λ; correspondingly, the multiple receiving antennas 1111 are also arranged with a second antenna spacing d2 that is no greater than λ / 2.

[0065] For the transmit beam: The primary purpose of this antenna spacing constraint is to avoid generating "grating lobes" in the transmit antenna pattern. A grating lobe refers to a side lobe with a gain similar to the main lobe. Once a transmit grating lobe appears, radar energy will be radiated simultaneously to multiple unrelated spatial directions. This not only wastes energy but also makes it impossible for the system to distinguish whether the target echo comes from the main lobe direction or the grating lobe direction, thus causing serious angle measurement errors.

[0066] For the receiving beam: This antenna spacing constraint also ensures that no grating lobes appear in the receiving antenna pattern. This is crucial for phase-based angle estimation algorithms. If grating lobes exist in the receiving pattern, a single target will generate multiple conflicting phase centers at the receiver, causing subsequent phase-based angle estimation algorithms to fail.

[0067] In a preferred embodiment, the plurality of transmitting antennas 1121 are arranged with a first antenna spacing d1 of λ / 2; correspondingly, the plurality of receiving antennas 1111 are also arranged with a second antenna spacing d2 of λ / 2.

[0068] Choosing the specific value λ / 2 ensures that, without generating grating lobes, the transmitting antenna array obtains the largest effective physical aperture when radiating signals, thereby forming the narrowest possible transmitting beam, which can greatly improve the system's angular resolution; at the same time, the receiving antenna array has a completely equivalent spatial sampling capability when receiving echoes, forming a receiving beam that matches the transmitting beam.

[0069] Furthermore, this antenna spacing provides a crucial guarantee for the robust performance of the phased array beam during large-angle scanning. When the pointing angle of the transmitted beam within the electronic scanning plane is large, the effective aperture of the transmitting antenna array decreases, leading to beam widening and a drop in gain. The λ / 2 antenna spacing provides ample design margin for this performance degradation, ensuring that the transmitted beam maintains a usable shape and gain throughout the entire electronic scanning range (e.g., ±51°).

[0070] In one embodiment, the transmitting antenna unit 112 and the receiving antenna unit 111 perform multiple electronic scans pointing to different directions within a preset frame period to complete the sampling of a corresponding frame of data, including:

[0071] The number of times the electronic scans are directed at different points is preset. Within each frame period, the transmitting antenna unit 112 controls the transmitting antenna 1121 to sequentially synthesize transmitting beams with different pointing angles a preset number of times by changing the phase difference between the signals of adjacent transmitting antennas 1121. To ensure continuous and complete coverage during multiple electronic scans, the pointing angle interval between two adjacent transmitting beams is configured to be no greater than half the width of the first 3dB beam. The specific implementation method of controlling the synthesis of a transmitting beam with a specific pointing direction by changing the phase difference between the signals of adjacent transmitting antennas 1121 has been described in the above embodiments and will not be repeated here.

[0072] Preferably, the pointing angle interval between two adjacent transmitted beams is equal to half the width of the first 3dB beam. This specific interval avoids detection blind spots caused by excessively large intervals, while preventing data redundancy and processing burden caused by excessively small intervals, thus providing a data foundation that balances completeness and efficiency for subsequent signal processing algorithms.

[0073] For each transmitted beam, the transceiver antenna unit 111 performs one data sampling. Once all the transmissions and samplings in different directions have been completed, a complete frame of sampled data is obtained.

[0074] The specific implementation process of a complete frame of sampled data has been described in the above embodiments and will not be repeated here.

[0075] In this embodiment, the preset number of electronic scans needs to be selected within a reasonable range: if the number of electronic scans is too small (e.g., only one scan), it will directly result in the total coverage area of ​​the electronic scan on the electronic scan plane being too small, and the performance advantages of the system cannot be fully utilized; the increase in the number of electronic scans means that the duration of a single frame period will be correspondingly longer. Under the premise that the rotation speed of the mechanical rotating device 10 is constant, this will result in the radar front-end module 11 having an excessively large physical rotation angle within a frame period. When this rotation angle exceeds the second 3dB beamwidth of the transmitted beam, the physical pointing reference of the transmitted beam will undergo a non-negligible deflection, resulting in a decrease in its pointing accuracy and ultimately leading to blurred imaging.

[0076] Therefore, in the system design of this invention, the preset number of electronic scans, the frame period duration, and the rotation speed of the mechanical rotating device 10 need to be coordinated and adapted to ensure that their values ​​can achieve a sufficiently large electronic scan coverage range while avoiding beam distortion introduced by mechanical rotation.

[0077] In one embodiment, the rotation angle of the mechanical rotation device 10 during each frame period is no greater than the second 3dB beamwidth. Corresponding the step angle of the mechanical rotation to the azimuth width of the transmitted beam (the second 3dB beamwidth) ensures that the coverage areas of the transmitted beams corresponding to two adjacent frame periods can continuously overlap in the azimuth dimension. This overlap design prevents detection blind spots in the scanning plane due to excessively large mechanical step angles.

[0078] Preferably, the rotation angle of the mechanical rotating device 10 during each frame period is equal to the second 3dB beamwidth. This selection ensures the continuity of detection while avoiding excessively long scanning time and data redundancy caused by too small a rotation step angle.

[0079] In one specific embodiment, a code disk is provided on the mechanical rotating device 10. The code disk is used to monitor the rotation angle of the mechanical rotating device 10 in real time and output it to the control and signal processing module 12, providing a position reference for the system to achieve scanning synchronization.

[0080] In one embodiment, such as Figure 6 As shown, the control and signal processing module 12 processes a complete frame of sampled data. This processing includes analyzing the three dimensions of the detected target: distance, velocity, and angle.

[0081] First, the sampled data undergoes a distance-dimensional Fast Fourier Transform (FFT). It's important to clarify that the sampled data is a temporally structured collection containing multiple sets of echo signals corresponding to different directional transmit beams. Specifically, within each frame period, the transmit antenna element 112 sequentially synthesizes multiple transmit beams with different directional angles. For each transmit beam, all receive antennas 1111 correspondingly acquire echoes and generate a time-domain sampling point sequence. Logically, a frame of sampled data constitutes a three-dimensional data set, with its dimensions corresponding to the number of sampling points, the number of transmit beams, and the number of receive antennas in each electronic scan.

[0082] By performing an FFT (Fast Fourier Transform) operation on all time-domain sampling point sequences within a frame period, the signal can be transformed from the time domain to the frequency domain. In this frequency domain, the peak frequency of the signal is proportional to the radial distance of the target, thereby resolving the target's distance information relative to the radar and forming a three-dimensional range-dimensional data matrix. The dimensions of this matrix are correspondingly the number of range gates, the number of transmit beams, and the number of receive antennas.

[0083] Secondly, after completing the range dimension analysis and forming the range dimension data matrix, the data matrix is ​​processed by the velocity dimension Fast Fourier Transform. Specifically, for each range gate and each receiving antenna in the matrix, the complex data sequence of multiple transmitted beams that are continuously transmitted across time is extracted, and the FFT operation is performed on this sequence.

[0084] The principle behind this operation is based on the Doppler effect of radar signals: for a moving target, the echoes reflected by multiple transmitted beams with different pointing angles will produce coherent phase changes in the receiving antenna 1111. By performing an FFT operation on this phase change sequence, a "Doppler frequency" proportional to the target's radial velocity can be obtained in the frequency domain, thereby resolving the target's velocity value.

[0085] After this step, the range-dimensional data matrix is ​​transformed into a velocity-dimensional data matrix. Based on the original dimensions, the "number of transmit beams" dimension is transformed into the "number of Doppler gates" dimension, forming a three-dimensional data matrix that includes the number of range gates, the number of Doppler gates, and the number of receive antennas.

[0086] Finally, angle-dimensional processing is performed based on the velocity-dimensional data obtained above. First, using digital beamforming technology, the complex data from different receiving antennas 1111 are coherently accumulated and weighted to synthesize multiple receiving beams that match the direction of the transmitted beam and are then detected, thereby obtaining coarse angle information of the target (its accuracy corresponds to half the width of the first 3dB beam). Second, for the detected target, based on its range and velocity gates, its complex data vectors on all receiving antennas 1111 are extracted from the velocity-dimensional data matrix, and a high-resolution angle estimation (DOA) algorithm (such as the MUSIC algorithm) is used to calculate the target's precise angle information.

[0087] It should be noted that the order of data processing for the distance, velocity, and angle dimensions can be selected based on the actual situation, and this invention does not impose any restrictions on this.

[0088] In one embodiment, the signaling control unit 122 and the signal processing unit 121 are integrated on a single chip. For example, a field-programmable gate array (FPGA) can be used.

[0089] 1. Control function: The FPGA internal logic implements the main control unit, which is responsible for managing the synchronization timing of the entire system, the preset parameter settings of each module, and the phase configuration switching of the transmission beam, etc.

[0090] 2. Signal processing function: The FPGA implements a signal processing unit 121 through parallel-designed hardware logic circuits, which is used to execute a series of algorithms such as distance dimension, velocity dimension and angle dimension at high speed.

[0091] 3. Integration Advantages: This highly integrated solution, through the hardware parallel processing capabilities and programmability of the FPGA, tightly integrates the system control signal processing, greatly optimizes the internal data flow, reduces processing latency, and ensures that complex algorithms are processed within a fixed frame period, thereby meeting the requirements for processing efficiency and real-time performance in the uniform rotation scanning mode.

[0092] In one embodiment, the signaling control unit 122 and the signal processing unit 121 are integrated on different chips. For example, the signaling control unit 122 is implemented by a microcontroller unit (MCU), which is responsible for managing the synchronization timing of the entire system, the preset parameter settings of each module, and controlling the phase configuration switching of the transmit beam, etc.; the signal processing unit 121 is implemented by a digital signal processor (DSP) or application-specific integrated circuit (ASIC), which focuses on high-speed execution of a series of algorithms in the distance, velocity, and angle dimensions.

[0093] To better describe the specific implementation scheme of the 24GHz rotating phased array millimeter-wave radar system, a preferred embodiment will be described below.

[0094] Example:

[0095] 1. System Configuration:

[0096] Mechanical rotating device 10: A motor is used to drive the radar front-end module 11 to rotate continuously at a uniform speed; and a code disk is set on the mechanical rotating device 10 to monitor its rotation angle in real time.

[0097] Radar front-end module 11: It is fixedly installed on the motor rotor, and its core components include: transceiver antenna unit 111 and transmitting antenna unit 112.

[0098] The transceiver antenna unit 111 includes an SRK2402 chip as a slave chip and an SRK2401 chip as a master chip. The SRK2401 chip is cascaded with the SRK2402 chip through a first interface. Four receiving antennas are linearly arranged on the two chips with a second antenna spacing d2 of λ / 2 and a second antenna arrangement direction B, respectively. When the two chips are cascaded, the spacing between the receiving antennas at the cascade point is maintained at the second antenna spacing d2. After cascading, eight receiving antennas 1111 are formed.

[0099] The transmitting antenna unit 112 includes an MSRT1111 chip, and eight transmitting antennas 1121 are linearly arranged on the MSRT1111 chip with a first antenna spacing d1 of λ / 2 and a first antenna arrangement direction A. The SRK2401 chip is connected to the MSRT1111 chip through a second interface. The first antenna arrangement direction A and the second antenna arrangement direction B are parallel. The transmitting antenna unit 112 operates in a phased array beamforming mode.

[0100] Transmit beam: The first 3dB beamwidth of the transmit beam, which is synthesized by 8 transmitting antennas 1121 and has a pointing angle of 0° in the electronic scanning plane, is ±6.375° and the second 3dB beamwidth is ±4.5°; the electronic scanning plane corresponding to the transmit beam is perpendicular to the rotation plane of the motor.

[0101] 2. System Scan:

[0102] This system employs a hybrid scanning mechanism that combines mechanical rotation with electronic scanning:

[0103] Mechanical rotation: One frame cycle is defined as 9° rotation of the motor.

[0104] Electronic scanning: Within each frame period, the transmitting antenna element 112 synthesizes 16 transmitting beams with different pointing angles sequentially in the electronic scanning plane by changing the phase difference between the signals of adjacent transmitting antennas 1121 at fixed intervals of 6.375°. Among them, the center pointing angle of the outermost transmitting beam is ±51°, thereby achieving electronic scanning coverage of ±51° in the electronic scanning plane.

[0105] Signal processing: Each electronic scan acquires 1024 sampling points, and after completing all 16 electronic scans within one frame period, the control and signal processing module 12 performs corresponding FFT data processing on the complete sampled data of the frame, and finally outputs the target distance, speed and angle information.

[0106] The FFT data processing in this preferred embodiment includes:

[0107] Range-dimensional FFT: Perform range-dimensional FFT operations on 8 receiving antennas 1111, 16 electronic scans, and 1024 sampling points corresponding to each electronic scan to transform the signal from the time domain to the frequency domain and output a range-dimensional data matrix of 512 (range gate) × 16 (transmit beam pointing) × 8 (receiving antenna 1111).

[0108] Velocity-dimensional FFT: Based on the Doppler effect, velocity-dimensional FFT calculations are performed on 16 consecutive beam pointing directions at each range gate and each receiving channel in the above range-dimensional data matrix. The transmit beam pointing dimension is converted into the velocity dimension, and a velocity-dimensional data matrix of 512 (range gate) × 16 (Doppler gate / velocity gate) × 8 (receiving antenna 1111) is output.

[0109] Coherent accumulation: In the velocity dimension data matrix, for each range gate and each velocity gate (i.e. each transmit beam pointing), the complex data corresponding to the same transmit beam pointing on the 8 receiving antennas 1111 are weighted and merged, and a range-velocity beam energy matrix of 512 (range gate) × 16 (transmit beam pointing) is output.

[0110] CFAR and Peak Detection: In the range-velocity beam energy matrix, constant false alarm rate (CFAR) detection and peak detection are performed to output the range, velocity, and approximate angle of the detected target. The angle resolution is determined by the electronic scanning pointing angle interval, with an accuracy of 6.375°.

[0111] High-resolution DOA estimation: For each target output by CFAR, the complex data vector of the target on the 8 receiving antennas is extracted from the higher-dimensional velocity dimension data matrix. The complex data vector is processed using a high-resolution angle estimation (DOA) algorithm (such as the multiple signal classification MUSIC algorithm) to output the precise angle of the target with an accuracy of < 1°.

[0112] Information output: Finally, the system outputs the target's distance, speed, and precise angle information.

[0113] The system design of this preferred embodiment can ultimately achieve full-range detection of 360° of the rotating plane and ±51° of the electronic scanning plane, and the intensity of the synthesized transmitted beam is improved by more than 3dB compared with TDM-MIMO. The detection range for weak targets reaches about 60 meters, which greatly improves the detection capability of weak targets.

[0114] Another embodiment of the present invention provides a 24GHz rotating phased array millimeter-wave radar device, including the 24GHz rotating phased array millimeter-wave radar system mentioned above. The specific implementation of the 24GHz rotating phased array millimeter-wave radar system of this embodiment has been described in the above embodiments and will not be repeated here.

[0115] In summary, the 24GHz rotating phased array millimeter-wave radar system, method, and device provided by this invention, by introducing a phased array beamforming operating mode and controlling the phase of the transmitting antenna elements, combines multiple transmitting antennas into a highly concentrated, strongly directional transmitting beam for electronic scanning. Compared to the traditional time-division multiplexing operating mode, the transmitting power is significantly improved, enhancing the detection capability and maximum detection range for weak targets. Simultaneously, by combining uniform, continuous mechanical rotation with electronic scanning within a frame period, a highly efficient hybrid scanning mechanism is constructed. This mechanism achieves full azimuth coverage scanning through mechanical rotation and performs multiple elevation scans in different directions within each preset frame period, collectively forming a spherical scan, greatly improving the radar's spatial coverage. Furthermore, by adapting the frame period duration to the mechanical rotation speed, the synchronization of electronic scanning, data acquisition, and processing is ensured, guaranteeing the continuous and reliable output of multi-dimensional information such as the range, velocity, and angle of the detected target.

[0116] Therefore, this application effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0117] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A 24 GHz rotating phased array millimeter wave radar system, characterized by, include: Mechanical rotating device; The radar front-end module is fixed on the mechanical rotating device and rotates continuously at a uniform speed following the mechanical rotating device; The radar front-end module includes a transmitting antenna unit and a receiving antenna unit, wherein the transmitting antenna unit operates in a phased array beamforming mode. The transmitting antenna unit and the receiving antenna unit perform multiple electronic scans pointing to different directions within each preset frame period to complete the sampling of a corresponding frame of data. The frame period duration is adapted to the rotation speed of the mechanical rotating device. The control and signal processing module receives and processes one frame of sampled data in each frame period and outputs multidimensional information of the detected target.

2. The 24 GHz rotating phased array millimeter wave radar system of claim 1, wherein, The transmitting antenna unit includes: a transmitting antenna unit chip, and multiple transmitting antennas disposed on the transmitting antenna unit chip, wherein the multiple transmitting antennas are linearly arranged on the transmitting antenna unit chip according to a preset first antenna spacing and a first antenna arrangement direction; The transceiver antenna unit includes: a transceiver antenna unit chip, and multiple receiving antennas disposed on the transceiver antenna unit chip. The multiple receiving antennas are linearly arranged on the transceiver antenna unit chip according to a preset second antenna spacing and a second antenna arrangement direction.

3. The 24 GHz rotating phased array millimeter wave radar system of claim 2, wherein, The transceiver antenna unit chip is connected to the transmit antenna unit chip, and the transceiver antenna unit chip is used to provide a radio frequency signal source for the transmit antenna unit chip.

4. The 24 GHz rotating phased array millimeter wave radar system of claim 2, wherein, The electronic scanning planes corresponding to the multiple electronic scans pointing to different points are perpendicular to the rotation plane of the mechanical rotating device; The transmitted beam synthesized by the multiple transmitting antennas includes: a first 3dB beamwidth in the electronic scanning plane, and a second 3dB beamwidth in a measurement plane perpendicular to the electronic scanning plane.

5. The 24 GHz rotating phased array millimeter wave radar system of claim 4, wherein, The number of transmitting antennas is the same as the number of receiving antennas.

6. The 24 GHz rotating phased array millimeter wave radar system of claim 4 or 5, wherein, The multiple transmitting antennas are arranged with a first antenna spacing of λ / 2, and the multiple receiving antennas are arranged with a second antenna spacing of λ / 2.

7. The 24 GHz rotating phased array millimeter wave radar system of claim 6, wherein, The transmitting antenna unit and the transceiver antenna unit perform multiple electronic scans pointing to different directions within a preset frame period to complete the sampling of a corresponding frame of data, including: Within each frame period, the transmitting antenna unit synthesizes a preset number of transmitting beams by changing the phase difference between the signals of adjacent transmitting antennas. The pointing angle interval between two adjacent transmitting beams is no greater than half the width of the first 3dB beam. The transmitting and receiving antenna unit completes multiple data samplings accordingly.

8. The 24 GHz rotating phased array millimeter wave radar system of claim 7, wherein, The rotation angle of the mechanical rotating device during each frame period is no greater than the second 3dB beamwidth.

9. The 24 GHz rotating phased array millimeter wave radar system of claim 1, wherein, The control and signal processing module receives and processes one frame of sampled data per frame period, and outputs multidimensional information about the detected target, including: Perform a distance-dimensional Fast Fourier Transform on the sampled data to extract the target's distance information; Perform a velocity-dimensional Fast Fourier Transform on the sampled data to extract the target's velocity information; The sampled data is processed to extract the angle information of the target.

10. A 24 GHz rotating phased array millimeter wave radar apparatus, characterized by, include: The 24GHz rotating phased array millimeter-wave radar system as described in any one of claims 1 to 8.

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