Single-base radar narrow beam antenna array and calibration method and system

Abstract

The invention belongs to the field of radars, and discloses a single-base radar narrow beam antenna array and a calibration method. A large-aperture antenna array design is adopted, so that the HPBW is effectively reduced, and the angle precision is improved; the antenna array is composed of a plurality of antenna units, the directions and shapes of beams can be flexibly adjusted by electronically controlling the phases and the amplitudes of all the units, and rapid and accurate beam scanning and tracking are achieved. The narrow-beam antenna array is superior to a double-layer structure wide-beam antenna array and a small-aperture antenna designed based on a single antenna in the aspect of HPBW. The calibration method selects a far-field calibration method and adopts an automatic measurement mode, directional diagrams of the transmitting antenna and the receiving antenna after calibration form sharp wave beams in the 0-degree direction, the power of a main lobe is improved by more than 10dBm compared with that before calibration, and the side lobe power of the wave beams is 10dBm lower than that of the main lobe.

Description

TECHNICAL FIELD

[0001] The present application belongs to but is not limited to the field of radar technology, and particularly relates to a single-base radar narrow-beam antenna array and a calibration method and system. BACKGROUND

[0002] Radar detects targets through electromagnetic waves and has the ability to penetrate through rain, snow, fog and other bad weather. Compared with optical sensors such as cameras, radar has the characteristics of all-weather, long detection distance, high accuracy of ranging and speed measurement, etc. At present, this technology has expanded from the military field to the civilian market, supporting emerging applications such as intelligent transportation, industrial detection and medical monitoring, and has become a key link in promoting intelligent upgrading.

[0003] In modern radar systems, the antenna is a key component and is the key node for realizing bidirectional conversion of spatial electromagnetic waves and electrical signals in the radar system, and shoulders the heavy responsibility of signal transmission and reception. Its design quality directly affects the overall performance of the radar.

[0004] The signal transmitted by the phased array antenna array is the superposition of the signals transmitted by all single antennas, and its performance depends on the accurate control of each antenna unit. Therefore, calibration is crucial for phased array antenna arrays. Each antenna unit forms a beam by adjusting the phase and controls its direction and shape. If there is an error in the phase of the array, it may cause the beam to point inaccurately or have an uneven radiation power distribution, thereby affecting the performance of the system.

[0005] In actual engineering, there are many problems. First, at the hardware composition level, there are process deviations in the manufacturing process of radio frequency chips, size deviations of antenna units, dispersion of material properties, and coupling between antennas. These factors will all cause differences between the theoretical calculation and the actual antenna beam. Second, from the signal transmission link, the loss characteristics of the transmission line in the transmission and reception channels of the radio frequency front end are different due to different materials and lengths. At the same time, poor contact of the connecting parts will introduce additional noise and signal attenuation. These factors will distort the transmission signal, and calibration is needed to compensate for the loss and distortion in the signal transmission process to ensure signal quality. Third, as the application scenarios of phased array antennas become increasingly complex, external environmental interference becomes more prominent. Changes in temperature and humidity will cause the antenna material to expand or shrink, thereby changing the electrical parameters; electromagnetic interference will disturb the normal signal and affect the detection accuracy of the antenna on the target. Calibration can identify and correct these problems in a timely manner, compensate for the phase and gain of each unit, adapt to environmental changes in real time, dynamically adjust the antenna parameters, and ensure that it works stably and accurately in complex and variable environments, continuously delivering optimal performance.

[0006] Therefore, calibration can not only improve the pointing accuracy of the array, but also improve the quality of the signal and the reliability of the system, especially in radar, communication, electronic warfare and other applications with high precision requirements, to ensure that the array can always meet the design performance standards.

[0007] The electronic scanning phased array antenna system shown in the prior art US6597312B1 is characterized by generating multiple beams using phase control and sharing the phase center to fully utilize the available power of large aperture radiation. The system adopts a planar phased array structure, each antenna element integrates a phase shifter, accurately controls the phase by electronic means, realizes flexible adjustment of beam direction and shape, and further suppresses the sidelobe or adjusts the beam amplitude distribution through the amplitude controller

[0008] Similar designs are widely used in many modern AESA (Active Electronically Scanned Array) radars, such as the PAVE PAWS radar, each element with an independent T / R module, achieving high power output and fast scanning. In the industrial literature, there are also many reviews on phased array antenna design and testing, pointing out that the general architecture and principles of such systems are highly consistent with the "multiple antenna elements controlled by electronic means to realize flexible adjustment of beam direction and shape" described in the claims of this application. Therefore, US6597312B1 and related AESA technology can be considered as the closest prior art.

[0009] Although the existing phased array can realize narrow beam through phase and amplitude adjustment, when realizing large aperture and element spacing less than half wavelength, the coupling and mutual influence between the elements will cause the actual beam to deviate from the ideal simulation results, affecting the angle accuracy and sidelobe suppression effect, and complex optimization is needed in the design and layout of the antenna elements. The integrated phase shifter and adjustable attenuator can accurately adjust the phase and amplitude, but the additional hardware circuits (such as PIN diodes, phase shifters, attenuators, T / R modules, etc.) of each element will significantly increase the system cost, power consumption and volume, and bring greater thermal management pressure, which requires more engineering resources in power amplification, heat dissipation design and reliability. When the beam is scanned at a large angle, the scanning gain loss, beam distortion (such as scanning tilt effect) and the appearance of stray sidelobes or zero regions need to be compensated by more complex beam forming networks or digital beam forming techniques, which puts higher requirements on real-time control and back-end signal processing. In the wideband or multi-frequency working scenario, the frequency response characteristics of the phase shifter and the attenuator may cause the beam pointing to deviate or the amplitude to be inconsistent at different frequencies, which requires additional measures such as true time delay elements or wideband phase shift design to ensure the stability of the beam performance, further increasing the design complexity SUMMARY

[0010] In view of the problems existing in the prior art, the present application provides a single-base radar narrow-beam antenna array and a calibration method.

[0011] The application is implemented as a single-base radar narrow-beam antenna array, which adopts a large-aperture planar array design and is composed of a plurality of antenna units with a spacing less than one-half of the working wavelength;

[0012] Each antenna unit integrates a phase modulation unit, an amplitude modulation unit and a thermal management structure, the phase modulation unit including a true time delay module for maintaining the consistency of different frequency band beam directions under wideband or multi-frequency working conditions;

[0013] The amplitude modulation unit includes a programmable attenuator for dynamically adjusting the amplitude response of each antenna unit to optimize the beam shape and sidelobe performance;

[0014] The thermal management structure includes a micro-channel liquid cooling channel or a high-thermal-conductivity substrate for maintaining stable operation of the array under high-power working conditions;

[0015] The array further includes an adaptive calibration network for measuring the output of each antenna unit in real time and correcting phase and amplitude errors through feedback control;

[0016] The antenna array has the functions of reducing the half-power beamwidth, suppressing far sidelobes, improving angular accuracy and enhancing wide-band directional Figure One consistency.

[0017] Further, the antenna unit integrates a phase shifter and an adjustable attenuator for high-precision adjustment of phase and amplitude.

[0018] The application also provides an antenna array calibration method, which includes the following steps:

[0019] (1) Build a transmission calibration scene, connect the radar, turntable and spectrum analyzer to the host computer through the communication protocol, and control the radar and spectrum analyzer and record the transmission beam conditions;

[0020] (2) Select a certain transmission antenna unit as a reference antenna, continuously adjust the register configuration of each transmission antenna unit, and synthesize the amplitude according to the spectrum analyzer data record until the optimal register configuration is obtained;

[0021] (3) Build a receiving calibration environment, make the calibration transmission source transmit signals of fixed frequency and fixed direction, and after the radar receives the signals, the host computer continuously adjusts the register configuration of each receiving antenna unit and records the receiving beam conditions until the optimal receiving configuration is determined.

[0022] Further, in step (2), the host computer uses a search algorithm to traverse the register values of each transmission antenna unit according to the transmission beam data of the reference antenna unit, records the corresponding synthesized amplitude, and writes the obtained optimal register configuration into the radio frequency chip.

[0023] Further, in step (3), the host computer controls the register of each receiving antenna unit to adjust step by step, determines the optimal phase setting of each register by reading the received radio frequency signal amplitude data, and saves the calibration result to the radio frequency chip.

[0024] The application also provides a radar system comprising the single-base radar narrow-beam antenna array of claim 1 and the antenna array calibration method of claim 4 implemented for the antenna array.

[0025] The application also provides an antenna array calibration device, which comprises:

[0026] A transmitting calibration chamber for accommodating the radar and the turntable;

[0027] A receiving calibration chamber for accommodating the receiving antenna and the calibration transmitting source;

[0028] A spectrum analyzer connected with the host computer through a network;

[0029] A host computer for performing the calibration process and recording the beam data by communicating with the radar, the turntable and the spectrum analyzer through a communication protocol;

[0030] The host computer calculates the optimal configuration of the register and loads it to the radio frequency chip according to the recorded data.

[0031] Further, the calibration transmitting source continuously transmits radio frequency signals of fixed frequency and fixed direction for receiving calibration.

[0032] The application also provides a radar, characterized in that the radar comprises a radio frequency chip cluster and a processor, and the register configuration of the radio frequency chip cluster adopts the calibration result of claim 5 or claim 6 to accurately control the phase and amplitude of each antenna unit in operation.

[0033] In combination with the above technical solutions and the solved technical problems, the technical solution to be protected by the application has the following advantages and positive effects:

[0034] Firstly, the narrow-beam antenna array of the application has achieved a revolutionary breakthrough in HPBW, and its performance is significantly superior to existing mainstream solutions. Compared with the 10° HPBW of the traditional double-layer structure wide-beam antenna array and the 3.1° HPBW of the small-aperture antenna based on single-antenna design, the HPBW of the application is compressed to 0.4°. This ultra-narrow beam characteristic directly translates into an 8-fold improvement in angle resolution, completely solving the angle ambiguity problem of wide-beam antennas in dense target scenarios. At the same time, its 23dB high-gain characteristic further enhances the signal detection capability, providing a hardware foundation for high-precision applications such as intelligent driving and industrial detection.

[0035] The automatic calibration method of the application is verified by experiments to have excellent effectiveness. Before calibration, the antenna pattern has problems of beam distortion and energy dispersion; after optimization by the rotating vector calibration system, the transmitting and receiving antennas form sharp main lobe beams in the 0° direction, and the performance improvement is reflected in two core indicators: the main lobe power is significantly enhanced, and the main lobe power after calibration is increased by more than 10 dBm compared with that before calibration, greatly improving the signal detection distance and signal-to-noise ratio; the sidelobe suppression capability is broken through, and the sidelobe power after calibration optimization is strictly suppressed to be 10 dBm lower than the main lobe power, effectively eliminating multipath interference and false targets.

[0036] Secondly, the application takes ultra-narrow beam width and high gain as the core advantages, and realizes a leap in angle resolution compared with traditional millimeter wave arrays. At the same time, relying on the full-automatic rotating vector calibration system, high-precision phase control is completed within minutes, the main lobe power is increased by more than 10 dBm, and the sidelobe is effectively suppressed by 10 dBm. This combination of technologies directly translates into three revenue paths: first, the hardware product can realize high-priced sales, and the high-performance array module, with its irreplaceability of 0.4° beam width and 23 dB gain, significantly enhances the pricing power in the high-end radar market, while the automatic calibration system reduces the cost of mass production, forming a double competitiveness of "high performance + low cost"; secondly, the calibration service can build sustainable revenue, providing mass production line calibration equipment and algorithm subscription services to radar manufacturers to solve the yield bottleneck of phased array antennas in mass production, while extending the service life of terminal equipment through periodic operation and calibration to bind long-term value of customers; finally, technology licensing will expand marginal revenue, and the array topology design and rotating vector calibration algorithm can be licensed to chip manufacturers to expand the revenue boundary.

[0037] Traditional millimeter wave arrays are limited by small aperture physical size, and the HPBW has been stuck at more than 3.1° for a long time, and the wide beam antenna is as high as 10°, which is difficult to meet the needs of high-precision scenarios. Through innovative array topology design, the application first realizes 0.4° ultra-narrow beam width under the same physical size, and the angle resolution is nearly 8 times higher than existing solutions, and the gain is increased to 23 dB.

[0038] Existing phased array calibration schemes at home and abroad generally rely on manual operation or semi-automatic equipment, and a single calibration takes several hours and has limited accuracy. The application builds a full-link automatic calibration system: based on the rotating vector method theory, the radar control end, spectrum analyzer and turntable are integrated through Python scripts to realize minute-level closed-loop calibration; the core innovation is to realize 5.625° phase stepping control through the PSR register, and combined with the real-time feedback of main lobe / sidelobe power data by the spectrum analyzer, the optimal phase combination is automatically optimized. The main lobe power after calibration is increased by more than 10 dBm, and the sidelobe suppression is 10 dBm, solving the large-scale production yield problem caused by hardware discreteness.

[0039] Industry tradition believes that: limited by the wavelength characteristics of millimeter wave band, the HPBW of small aperture antenna array must be greater than 3.1°, and the wide beam double-layer structure can simplify the design but the HPBW is greater than or equal to 10°. The present application realizes 0.4° ultra-narrow beam width under the same physical size through innovative array topology design, which is nearly 8 times higher than the traditional small aperture array, while maintaining a high gain of 23dB, which proves that small size antennas can realize ultra-high angular resolution and completely break the inherent cognition that size and precision cannot be compatible. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is the antenna array design diagram provided by the embodiment of the present application;

[0041] Figure 2 is the principle diagram of the rotating vector method provided by the embodiment of the present application;

[0042] Figure 3 is the transmission calibration field diagram provided by the embodiment of the present application: (a) radar during calibration; (b) frequency spectrum instrument receiving end for calibration;

[0043] Figure 4 is the block diagram of the transmission calibration provided by the embodiment of the present application;

[0044] Figure 5 is the corresponding power diagram of the transmission phase shifter provided by the embodiment of the present application;

[0045] Figure 6 is the transmission calibration result diagram provided by the embodiment of the present application;

[0046] Figure 7 is the receiving calibration field diagram provided by the embodiment of the present application: (a) standard transmission source for calibration; (b) radar during calibration;

[0047] Figure 8 is the block diagram of the receiving calibration provided by the embodiment of the present application;

[0048] Figure 9 is the corresponding power diagram of the receiving phase shifter provided by the embodiment of the present application;

[0049] Figure 10 is the receiving calibration result diagram provided by the embodiment of the present application;

[0050] Figure 11 is the antenna array directional diagram simulation provided by the embodiment of the present application: (a) small aperture antenna directional diagram simulation three-dimensional diagram; (b) small aperture antenna directional diagram simulation two-dimensional diagram; (c) antenna directional diagram simulation three-dimensional diagram designed by the present application; (d) antenna directional diagram simulation three-dimensional diagram designed by the present application. DETAILED DESCRIPTION

[0051] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0052] The embodiment of the present application provides a single base radar narrow beam antenna array which is composed of a plurality of antenna units, the phase and amplitude of each unit are controlled by electronics, the beam direction and shape can be flexibly adjusted, and fast and accurate beam scanning and tracking are realized. This electronic scanning does not need mechanical rotation, has fast response speed and high reliability, and is particularly suitable for scenes such as radar, communication and satellite tracking.

[0053] The traditional millimeter wave radar antenna array often uses a small aperture antenna array, which will increase the E-plane HPBW (Half-Power Beamwidth) of the antenna, so that the angle accuracy is poor. Although the double-layer structure wide beam antenna provides a certain reference value for the design of the antenna array of the millimeter wave radar, the HPBW is generally 10°, which cannot meet the high-precision point cloud imaging. The large-aperture antenna array design adopted in the present application can effectively reduce the HPBW and increase the angle accuracy. The antenna array design is as shown in Figure 1 .

[0054] The common calibration is divided into near-field calibration and far-field calibration. The near-field calibration is performed in a region close to the antenna, and the distance between the probe and the phased array antenna to be measured is usually 3-5 times the wavelength of the test signal of the vector network analyzer; the far-field calibration requires that the measurement distance satisfies the far-field condition, and generally has the constraint as shown in formula (1-1).

[0055]

[0056] In the formula, D is the antenna aperture, λ is the wavelength, and R is the distance between the array antenna and the receiving end.

[0057] Compared with the near-field calibration, the far-field calibration has lower implementation difficulty, simple equipment requirement and better calibration effect, so the far-field calibration method is selected in the present application.

[0058] In the present application, the antenna aperture D is 0.481 m, the wavelength λ is about 3.846 mm, and formula (1-1) is substituted into formula (1-1) to obtain:

[0059] R>120.31m (1-2)

[0060] That is, the antenna needs to keep a distance of more than 120 m from the receiving end during calibration.

[0061] The commonly used method for far-field calibration is the rotating vector method. The basic principle of the rotating vector method is as follows: For a phased array antenna array, the signal transmitted by each antenna can be considered as a vector, and the synthesized signal is the superposition of the signals from each individual antenna. While keeping the amplitude and phase of other antennas constant, calibration is achieved by controlling the phase of one antenna to vary between 0 and 360 degrees and measuring the amplitude of the synthesized signal. Hence, it is called the rotating vector method. Its principle is as follows: Figure 2 As shown.

[0062] exist Figure 2 middle, These are the signals transmitted by the four single antennas, and Q is the signal synthesized by the phased array antenna, as shown in equation (1-3).

[0063]

[0064] Keep By keeping the three vectors fixed and changing the value of Q, maximizing the Q value is achieved. Calibration. For the RF chip ADT2001, the phase of a single antenna is controlled by the Program Status Register (PSR) register. The value of the PSR register is 0-63, corresponding to a phase of 0-2π, that is, the phase control accuracy is 5.625 degrees.

[0065] Since calibration requires constantly changing the PSR register to change the Q value, which is too cumbersome, this paper adopts an automated measurement method. First, a system is built as follows: Figure 3 The launch calibration scenario shown is as follows. Figure 3 (a) is the transmitting dark box for calibrating the transmitting antenna. 1 is the radar and 2 is the turntable. Both are connected to the computer through a specific protocol and are controlled by the computer. Figure 3 (b) is the receiving dark box for calibrating the transmitting antenna, 3 is the receiving horn antenna, 4 is the spectrum analyzer. The horn antenna is connected to the spectrum analyzer via a coaxial cable. The spectrum analyzer is connected to the computer via a network cable. The computer accesses the data of the spectrum analyzer through the Standard Commands for Programmable Instruments (SCPI) protocol.

[0066] The system block diagram for calibrating the transmitting antenna is as follows: Figure 4As shown, the host computer runs the python script, first selects a certain root antenna as the reference antenna, sends instructions to the radar through the serial port to configure the PSR register of each transmitting antenna of each chip in the radar, at the same time reads the current radar board transmitting beam from the spectrum analyzer, records the corresponding synthesized amplitude of each PSR register, until the optimal register configuration is found. And save the optimal register configuration result, write the calibrated result into the RF chip when using the radar.

[0067] Select four of the antenna channels, draw the curve of the synthesized signal power of each channel and the reference channel changing with the PSR register, as shown in Figure 5 . By observation, it is found that the power of the synthesized signal changes with the change of the PSR register of the antenna.

[0068] After calibration, the host computer controls the turntable to drive the radar board to rotate, and reads the corresponding data, to obtain the beam pattern, and finally obtain the beam pattern as shown in Figure 6 .

[0069] Build a receiving calibration environment as shown in Figure 7 . Figure 7 (a) is the transmitting dark box when calibrating the receiving antenna, and the red box shows the 3102 transmitting source that transmits the standard signal to the radar, Figure 7 (b) is the receiving dark box when calibrating the receiving antenna, which is the same as Figure 3 (a).

[0070] The block diagram of calibrating the receiving antenna is shown in Figure 8 . When calibrating the receiving, the 3102 transmitting source transmits a beam of fixed frequency and fixed direction, the radar board receives the beam, the host computer changes the PSR register of each receiving antenna of each chip of the radar to adjust the antenna phase, at the same time reads the received beam from the radar board, until the optimal solution is found.

[0071] Similarly, select four of the antenna channels, draw the curve of the synthesized signal power of each channel and the reference channel changing with the PSR register, as shown in Figure 9 . By observation, it is found that the power of the synthesized signal changes with the change of the PSR register of the antenna.

[0072] After calibration, the host computer controls the turntable to drive the radar board to rotate, and reads the corresponding data, to obtain the beam pattern. As shown in Figure 10 .

[0073] From Figure 6 and Figure 10It can be seen from the figures that: after calibration, the directional patterns of the transmitting antenna and the receiving antenna both form sharp beams in the 0° direction, compared with before calibration, the power of the main lobe is increased by more than 10 dBm, and the side lobe power of the beam is lower than the main lobe by 10 dBm. It can be shown that the calibration method designed in the application is effective.

[0074] Based on the three core technologies of 0.4° ultra-narrow beam, 10 dBm main lobe enhancement and side lobe suppression, and minute-level dynamic calibration, the millimeter wave antenna array of the application realizes breakthrough application in the following fields:

[0075] In the field of intelligent driving and traffic monitoring, the 0.4° ultra-narrow beam realizes 1.4 meter angle resolution at a distance of 200 meters, accurately distinguishing adjacent lane dense vehicles; the 10 dBm side lobe power suppression capability eliminates the multipath reflection of guardrails, road signs, etc., and reduces the false target rate by more than 90%; the calibration system guarantees that the main lobe power fluctuation is less than or equal to ±1 dBm in the environment of-40℃ to 85℃, meeting the all-weather reliability requirements of vehicle level.

[0076] In the field of industrial automation and precision detection, 23 dB high gain combined with 0.4° beam realizes sub-millimeter positioning accuracy for 0.1 mm level mechanical vibration; 10 dBm side lobe suppression shields equipment multipath interference in strong reflection workshops, and the signal-to-noise ratio is improved by 10 times; minute-level automatic calibration supports continuous operation of production lines, and real-time compensation of mechanical arm motion deformation error.

[0077] In the field of low-altitude security and unmanned aerial vehicle control, the 0.4° beam has a bearing resolution of 0.7 meters for a group of unmanned aerial vehicles in a 100-meter airspace, realizing a tracking capacity of more than 10 per square kilometer; the dynamic calibration system suppresses the beam distortion caused by rain and snow, and the main lobe power stability is ±1 dBm, guaranteeing the continuous monitoring capability in extreme weather.

[0078] In order to verify the performance of the antenna array designed in the application, the data of the antenna array and a single antenna are imported into MATLAB, the directional pattern simulation of the phased array antenna array is carried out in MATLAB, and the small aperture array based on a single antenna is also simulated, and the simulation results are as shown in Figure 11 Figure 11 (a) and (b) are the simulation three-dimensional and two-dimensional results of the small aperture (32λ) array antenna directional pattern, the maximum power is about 15 dB, and the HPBW is about 3.1°. Figure 11 (c) and (d) are the simulation of the narrow beam antenna array designed in the application, from which it can be seen that the maximum power is about 23 dB, and the HPBW is about 0.4°, which is much better than the antenna array shown in Figure 11 (a) and (b).

[0079] ​Through simulation, it is known that the narrow-beam antenna array of the application is not only superior to the double-layer wide-beam antenna array in the aspect of HPBW, but also superior to the small-aperture antenna based on the single-antenna design.

[0080] It should be noted that the embodiments of the present application can be realized by hardware, software or a combination of software and hardware. The hardware part can be realized by special logic; the software part can be stored in a memory and executed by a suitable instruction execution system, such as a microprocessor or a specially designed hardware. Those skilled in the art can understand that the above-mentioned devices and methods can be realized by computer executable instructions and / or included in processor control codes, for example, such codes are provided on a carrier medium, such as a magnetic disk, a compact disc (CD) or a digital versatile disc-read only memory (DVD-ROM), a programmable memory, such as a read-only memory, or a data carrier, such as an optical or electronic signal carrier. The devices of the present application and their modules can be realized by hardware circuits, such as very large scale integrated circuits or gate arrays, semiconductors, such as logic chips, transistors, etc., or programmable hardware devices, such as field programmable gate arrays, programmable logic devices, etc., by software executed by various types of processors, or by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0081] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any modification, equivalent replacement and improvement made by those skilled in the art within the technical range disclosed by the present application, as long as it is within the spirit and principle of the present application, should be covered within the protection scope of the present application.

Claims

1. A single base radar narrow beam antenna array, characterized by, The antenna array adopts a large-aperture design, and is designed as a large-aperture planar array composed of a plurality of antenna units with a spacing less than one-half of a working wavelength; Each antenna unit is integrated with a phase modulation unit, an amplitude modulation unit and a thermal management structure, the phase modulation unit including a true time delay module for maintaining the consistency of different frequency band beam directions under wideband or multi-frequency working conditions; The amplitude modulation unit includes a programmable attenuator for dynamically adjusting the amplitude response of each antenna unit to optimize the beam shape and sidelobe performance; The thermal management structure includes a micro-channel liquid cooling channel or a high-thermal-conductivity substrate for maintaining stable operation of the array under high-power working conditions; The array further includes an adaptive calibration network for measuring the output of each antenna unit in real time and correcting phase and amplitude errors through feedback control.

2. The single-base radar narrow-beam antenna array of claim 1, wherein, The plurality of antenna units are arranged in a planar array with a spacing between the units less than one-half of a working wavelength.

3. The single-base radar narrow-beam antenna array of claim 1, wherein, The antenna units are integrated with a phase shifter and an adjustable attenuator for high-precision adjustment of the phase and amplitude.

4. A method of antenna array calibration, the method comprising: The method includes the following steps: (1) Set up a transmission calibration scene, connect the radar, turntable and spectrum analyzer to the host computer through a communication protocol, control the radar and spectrum analyzer by the host computer, and record the transmission beam conditions; (2) Select a certain transmission antenna unit as a reference antenna, continuously adjust the register configuration of each transmission antenna unit, and synthesize the amplitude according to the spectrum analyzer data record until the optimal register configuration is obtained; (3) Set up a receiving calibration environment, make the calibration transmission source transmit signals of a fixed frequency and a fixed direction, continuously adjust the register configuration of each receiving antenna unit by the host computer after the radar receives the signals, and record the receiving beam conditions until the optimal receiving configuration is determined.

5. The antenna array calibration method of claim 4, wherein, In step (2), the host computer uses a search algorithm to traverse the register values of each transmission antenna unit according to the transmission beam data of the reference antenna unit, records the corresponding synthesized amplitude, and writes the obtained optimal register configuration into the radio frequency chip.

6. The antenna array calibration method of claim 4, wherein, In step (3), the host computer controls the register of each receiving antenna unit to adjust gradually, determines the optimal phase setting of each register by reading the received radio frequency signal amplitude data, and saves the calibration results to the radio frequency chip.

7. A radar system, characterized by The single-base radar narrow-beam antenna array of claim 1 and the antenna array calibration method of claim 4 implemented for the antenna array.

8. An antenna array calibration apparatus, characterized by, The device comprises: a transmission calibration chamber for accommodating the radar and the turntable; a receiving calibration chamber for accommodating the receiving antenna and the calibration transmission source; a spectrum analyzer connected to the host computer through a network; a host computer for executing the calibration process and recording the beam data by communicating with the radar, the turntable and the spectrum analyzer through a communication protocol; The host computer calculates the optimal register configuration according to the recorded data and loads it into the radio frequency chip.

9. The antenna array calibration apparatus of claim 8, wherein, The calibration transmission source continuously transmits radio frequency signals of a fixed frequency and a fixed direction for receiving calibration.

10. A radar, characterized by The radar includes a radio frequency chip cluster and a processor, and the register configuration of the radio frequency chip cluster uses the calibration results of claim 5 or claim 6 to accurately control the phase and amplitude of each antenna unit in operation.

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