Phased array antenna

Abstract

The invention relates to the technical field of phased-array antennas, in particular to a phased-array antenna which comprises an ultra-wide-band receiving unit, a digital beam forming processor and three annular arrays with sequentially continuous frequency bands, the ultra-wide-band receiving unit is electrically connected with the digital beam forming processor and the three annular arrays, and the digital beam forming processor is electrically connected with the three annular arrays. The ultra-wideband receiving unit is used for controlling selection of annular array signals of three frequency bands, amplitude limiting, filtering and down-conversion processing are carried out on the detected signals, the signals are converted into intermediate-frequency signals, then the analog intermediate-frequency signals are converted into digital signals through sampling by the digital beam forming processor, and then the steps of signal detection, searching, parameter measurement and the like are completed. By adopting a frequency-band-division processing mode, the array element size of a low-frequency band can be increased, the array element spacing can be increased, the antenna gain of the low-frequency band is ensured, and meanwhile, the ultra-wideband receiving unit and the digital beam forming processor are combined, so that relatively good receiving and transmitting performance can be obtained at the frequency band of 0.38-18GHz.

Description

[0001] This case is a divisional application of the invention patent with the application date of December 29, 2023, the application number of CN202311861788.0, and the name of a high-bandwidth phased array antenna. TECHNICAL FIELD

[0002] The present application relates to the technical field of phased array antennas, in particular to a phased array antenna. BACKGROUND

[0003] The conventional phased array antenna usually uses a narrowband signal, and adjusts the amplitude and phase of each channel by using phase and amplitude digital control or continuously adjustable phase shifters and attenuators, so as to realize the adjustment of the antenna array beam pointing. For the phased array system using instantaneous wideband signal, the frequency dispersion phenomenon caused by the aperture effect cannot be ignored in the case of large aperture and large scanning angle range. The aperture effect will limit the signal bandwidth and scanning angle range of the phased array radar system, thereby seriously affecting the performance of the radar system. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a high-bandwidth phased array antenna that can reduce the limitation of aperture transition phenomenon on the signal bandwidth of the phased array radar.

[0005] In order to solve the above technical problems, the technical scheme adopted by the present application is: A high-bandwidth phased array antenna, comprising an ultra-wideband receiver group, a digital beam forming processor and three frequency band continuous ring arrays, the ultra-wideband receiver group is electrically connected with the digital beam forming processor and the three ring arrays respectively.

[0006] The present application has the following beneficial effects: This scheme uses an ultra-wideband receiver to control the selection of signals from a three-band ring array, and performs amplitude limiting, filtering, and down-conversion processing on the detected signals to convert them into intermediate frequency (IF) signals. A digital beamforming processor then samples and converts the analog IF signals into digital signals, completing signal detection, search, parameter measurement, and direction-finding beamforming. The ultra-wideband receiver and digital beamforming processor perform selection, amplitude limiting, amplification, and network calibration for each RF signal. The ultra-wideband receiver amplifies the RF signals via repeaters to overcome signal attenuation caused by excessive cable length, and simultaneously generates omnidirectional RF signals. The system includes RF self-test and function control; the digital beamforming processor enables instantaneous frequency measurement modules and direction-finding circuits in three frequency bands, measuring the frequency and azimuth of each arriving pulse; the high-bandwidth phased array antenna designed in this scheme adopts a frequency-band processing method, dividing the frequency into three segments. This increases the element size and spacing in the low-frequency band, ensuring the antenna gain in the low-frequency band. Combined with the ultra-wideband receiver and digital beamforming processor, it can achieve better receiving / transmitting performance in the 0.38GHz-18GHz frequency band, thereby reducing the limitation of the phased array radar signal bandwidth by the aperture crossing phenomenon. Attached Figure Description

[0007] Figure 1 A connection block diagram of a high-bandwidth phased array antenna according to the present invention; Figure 2 A top view of the layout of a ring array of high-bandwidth phased array antennas according to the present invention; Figure 3 A side view of the layout of a ring array of high-bandwidth phased array antennas according to the present invention; Figure 4 A connection block diagram of an ultra-wideband receiver unit with a high-bandwidth phased array antenna according to the present invention; Figure 5 This is a schematic diagram of the 0.38GHz~2GHz circular array phased array antenna arrangement of the high-bandwidth phased array antenna according to the present invention; Figure 6 Example diagrams of beam directions for high-bandwidth phased array antennas of the present invention under different element spacings; Figure 7 This is a schematic diagram of the 2GHz~6GHz rectangular grid phased array antenna arrangement of the high-bandwidth phased array antenna according to the present invention. Figure 8 This is a schematic diagram of the 6GHz~18GHz triangular grating phased array antenna arrangement of the high-bandwidth phased array antenna according to the present invention. Label Explanation: 1. Ultra-wideband receiver unit; 11. Limiter; 12. Low-noise amplifier; 13. Mixer; 14. Filter; 15. Coupler; 16. Gain-controlled intermediate frequency amplifier; 17. Digitally controlled attenuator; 18. Detector; 19. First switch; 110. Second switch; 2. Digital beamforming processor; 3. Ring array; 31. Antenna subarray; 4. Virtual circle; 5. Virtual square. Detailed Implementation

[0008] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0009] Please refer to Figure 1 The technical solution adopted in this invention is as follows: A high-bandwidth phased array antenna includes an ultra-wideband receiver unit, a digital beamforming processor, and three sequentially arranged ring arrays of frequency bands. The ultra-wideband receiver unit is electrically connected to the digital beamforming processor and the three ring arrays, respectively.

[0010] As can be seen from the above description, the beneficial effects of the present invention are as follows: This scheme uses an ultra-wideband receiver to control the selection of signals from a three-band ring array, and performs amplitude limiting, filtering, and down-conversion processing on the detected signals to convert them into intermediate frequency (IF) signals. A digital beamforming processor then samples and converts the analog IF signals into digital signals, completing signal detection, search, parameter measurement, and direction-finding beamforming. The ultra-wideband receiver and digital beamforming processor perform selection, amplitude limiting, amplification, and network calibration for each RF signal. The ultra-wideband receiver amplifies the RF signals via repeaters to overcome signal attenuation caused by excessive cable length, and simultaneously generates omnidirectional RF signals. The system includes RF self-test and function control; the digital beamforming processor enables instantaneous frequency measurement modules and direction-finding circuits in three frequency bands, measuring the frequency and azimuth of each arriving pulse; the high-bandwidth phased array antenna designed in this scheme adopts a frequency-band processing method, dividing the frequency into three segments. This increases the element size and spacing in the low-frequency band, ensuring the antenna gain in the low-frequency band. Combined with the ultra-wideband receiver and digital beamforming processor, it can achieve better receiving / transmitting performance in the 0.38GHz-18GHz frequency band, thereby reducing the limitation of the phased array radar signal bandwidth by the aperture crossing phenomenon.

[0011] Furthermore, the ring array includes four antenna elements, one end of which is arranged at equal intervals on the circumference of the same virtual circle, and the other end of which is located on the four sides of the same virtual square. The center of the virtual square coincides with the center of the virtual circle, and the antenna element includes four antenna subarrays that are non-uniformly arranged on the sides of the virtual square.

[0012] As described above, by setting up the aforementioned ring array, instantaneous omnidirectional coverage of 360° in all directions can be achieved, thereby reducing aperture effects and improving the performance of the radar system.

[0013] Furthermore, the antenna subarray is tilted along the edge of the virtual square.

[0014] As described above, the effect of tilting the antenna subarray is to make the radiated beams cross diagonally in space. If the beam is narrow, the time between different frequency pulse groups is longer, which can compensate for the antenna rotation scanning and make the radar stay at each elevation angle for a longer time, which is conducive to obtaining a better target detection probability.

[0015] Furthermore, the spacing between two adjacent antenna subarrays in the four antenna subarrays located in the same antenna element increases sequentially in a counterclockwise direction.

[0016] As described above, conventional uniformly periodic finite scanning arrays exhibit grating lobes due to the spacing exceeding one wavelength, leading to receiver angular multivariability and mistracking of the target. Grating lobe formation can be suppressed by increasing the spacing between adjacent antenna subarrays within the same antenna element in a counter-clockwise direction (i.e., using an aperiodic array of antenna subarrays). This further reduces aperture effects, thereby improving radar system performance.

[0017] Furthermore, the antenna subarray is an Archimedes spiral antenna.

[0018] As described above, as the operating frequency changes, the main radiating band of the Archimedes spiral antenna moves on the surface of the spiral antenna. When the frequency decreases, the diameter of the main radiating band increases and moves towards the periphery of the spiral antenna; when the frequency increases, the diameter of the main radiating band decreases and moves towards the inner circle of the spiral antenna. However, no matter how the operating frequency changes within the operating frequency band, the radiation pattern of the Archimedes spiral antenna can remain basically unchanged. Therefore, this type of antenna can achieve an extremely wide operating bandwidth.

[0019] Furthermore, the frequency bands of the three ring arrays are 0.38GHz~2GHz, 2GHz~6GHz and 6GHz~18GHz, respectively.

[0020] Furthermore, the ultra-wideband receiver unit includes a limiter, a low-noise amplifier, a mixer, a filter, a coupler, and a gain-controlled intermediate frequency amplifier connected in sequence. A digitally controlled attenuator is also connected between the limiter and the mixer. The ultra-wideband receiver unit also includes a detector, which is electrically connected to the coupler.

[0021] As described above, the 0.38GHz~18GHz signals input from the three-segment phased array antennas are first limited by a limiter to prevent excessive input signals from burning out subsequent circuits. The signal amplitude detected by the subsequent detector is then controlled by a switch. If the signal amplitude exceeds a set threshold, it passes through a digitally controlled attenuator channel, where the attenuation is appropriately controlled based on the amplitude. Conversely, it enters a low-noise amplifier for amplification. After amplitude processing, the signal enters a mixer, which controls the local oscillator output to a 1800MHz center frequency and a 1000MHz bandwidth intermediate frequency (IF) signal. The IF signal is then filtered to remove image frequencies. The filtered signal is output through a coupler, with the coupler's port connected to a detector for signal detection. The coupler's through-port outputs to a gain-controlled IF amplifier, whose gain is controlled to meet the requirements of different data types, such as blind sampling, pulse sampling, broadband, and narrowband.

[0022] Furthermore, the low-noise amplifier and the digitally controlled attenuator are connected to the limiter via a first switch, and the low-noise amplifier and the digitally controlled attenuator are connected to the mixer via a second switch.

[0023] Furthermore, the digital beamforming processor includes a GPU chip and an FPGA chip, both of which are electrically connected to the ultra-wideband receiver unit.

[0024] As described above, the GPU+FPGA-based architecture can simultaneously meet the requirements of ultra-wideband signal acquisition and high-speed data processing.

[0025] Furthermore, the ultra-wideband receiver unit is electrically connected to the three ring arrays via a three-to-one signal selection switch.

[0026] Please refer to Figures 1 to 8 As shown, Embodiment 1 of the present invention is as follows: Please refer to Figure 1 A high-bandwidth phased array antenna includes an ultra-wideband receiver group 1, a digital beamforming processor 2, and three sequentially arranged ring arrays 3. The ultra-wideband receiver group 1 is electrically connected to the digital beamforming processor 2 and the three ring arrays 3, respectively.

[0027] Please refer to Figure 2 and Figure 3 The ring array 3 includes four antenna elements. One end of the four antenna elements is arranged at equal intervals on the circumference of the same virtual circle 4. The other end of the four antenna elements is located on the four sides of the same virtual square 5. The center of the virtual square 5 coincides with the center of the virtual circle 4. The antenna element includes four antenna subarrays 31 that are non-uniformly arranged on the sides of the virtual square 5.

[0028] Please refer to Figure 2 The antenna subarray 31 is tilted and arranged on the side of the virtual square 5.

[0029] Please refer to Figure 3 The spacing between two adjacent antenna subarrays 31 located in the same antenna element increases sequentially in a counterclockwise direction.

[0030] The antenna subarray 31 is an Archimedes spiral antenna, which can obtain bidirectional circularly polarized radiation in a wide frequency band. Moreover, the input impedance of the antenna remains unchanged in a wide frequency band. By adding a reflector cavity to the back of the antenna, a unidirectional circularly polarized radiation antenna can be obtained. Its wide frequency band characteristics just meet the requirements of radar countermeasures.

[0031] The frequency bands of the three ring arrays 3 are 0.38GHz~2GHz, 2GHz~6GHz and 6GHz~18GHz, respectively.

[0032] After the sixteen Archimedes spiral antennas are arranged into a circular array, the diameters of the three frequency bands of the circular array 3 are 1.6m (0.38GHz~2GHz), 0.3m (2GHz~6GHz) and 0.16m (6GHz~18GHz), respectively, and the height is 0.35m.

[0033] The Archimedes spiral antenna (hereinafter referred to as the spiral antenna) has the following main parameters, which determine the basic characteristics of the antenna and should be selected according to the following principles: (1) Outer diameter D of the helical antenna: The outer diameter of the helical antenna is determined by the lower limit of its operating frequency band. The maximum wavelength corresponding to the lower limit frequency is denoted as D. Let C be the circumference of the outermost ring. Generally, D must satisfy the following conditions: ; (2) Inner diameter of the helical antenna The inner diameter of the spiral is the spacing between the feed points, which is determined by the upper limit frequency within the antenna's operating band and affects impedance matching. It is generally taken as... Not greater than , This indicates the wavelength corresponding to the upper limit frequency. (3) Growth rate α of helical antenna: The radius of curvature of helical antenna and the growth rate α of helical antenna have the same trend. When the outer diameter D of the helix is ​​fixed, different growth rates α of helical antenna will lead to changes in antenna performance. For example, when α is small, the total length of the coil increases with the increase of the number of coil turns n, more energy is radiated and the terminal effect is reduced, which improves the radiation efficiency of the antenna and maintains good band characteristics. Conversely, when α is large, the number of coil turns decreases and the loss increases, which greatly reduces the radiation efficiency of the antenna. Therefore, the selection of α should be appropriate. (4) Arm width W of the spiral antenna: When the arm width of the antenna and the gap between adjacent arms are equal, we call it "self-complementary". The theoretical input impedance of this type of antenna is 188.5Ω.

[0034] The specific method for calculating the diameter of the 0.38GHz~2GHz ring array 3 is as follows: Based on the structure and working principle of the helical antenna, the selection parameters for the detection helical antenna element in this frequency band are calculated: ① Maximum wavelength: ; ② Circumference of the outermost ring: ; ③Outer diameter of the helical antenna: ; For the 0.38GHz~2GHz frequency band, a 1×16 circular array is used, which is equivalent to a one-dimensional 16-element scanning phased array, such as... Figure 5 As shown, the spacing between adjacent units is d, and the beam direction is at an angle θ to the z-axis.

[0035] Each unit port is connected to a phase shifter, which controls the feed phase of each unit to achieve beam scanning.

[0036] Assuming each element is fed with equal amplitude and the radiation pattern of each element is identical, the normalized far-field array radiation pattern can be obtained by superimposing the radiation patterns of N elements, calculated according to the following formula: ; in ,Depend on If obtained, then , It is a frequency of wavenumber of time, It is the complex weight coefficient of the nth array element. This refers to the radiation pattern of a single antenna element (assuming the radiation pattern of each antenna element is equal). For this one-dimensional scanning array, when the desired beam points... At that time, weighting coefficient Defined as: ; Therefore, the matrix factor is: ; in, This expression indicates the use of a phase shifter to set the weighting coefficients. The above equation shows that the matrix factor is The direction pattern is a function of the direction cosine space, so if the array scans to certain angles, the direction pattern has a translation, but the shape remains unchanged. This is the main reason for using variables u and v, which are often referred to as the direction cosine space. Normalizing the above formula, we get: ; In the above formula, the expression achieves its maximum value when the denominator is 0, that is, when... When the beam gain is at its maximum, the maximum value appearing in the specified direction is called the main lobe beam; when more than one maximum value appears in the visible area, i.e., the ±90° area, the others are called grating lobes in addition to the main lobe in the required direction. The position of the grating petals is determined by Confirmed. Therefore, when At this time, no grating lobes will appear in the visible area. This is the condition for initially determining the element spacing of the phased array, namely: ; When the beam is pointed in the direction of the array surface normal, the radiation pattern under different element spacings is as follows: Figure 6 As shown, it can be seen that as the element spacing increases, the grating lobes gradually appear within the visible area; when the element spacing is 0.5 wavelengths, there are no grating lobes in the visible area; when the element spacing increases to one wavelength, the grating lobes appear at positions of ±90°; when the element spacing is 1.5 wavelengths, the grating lobes appear at positions of ±45°.

[0037] Since the axial mode is more suitable for radar signal reception, D in this frequency band can be taken as 0.314m. The condition of no grating lobes is met. Therefore, a helical antenna with an outer diameter D of 31.4 cm is selected and evenly arranged on the circumference, which gives a circumference diameter of 1.6 m.

[0038] The specific method for calculating the diameter of the 2GHz~6GHz ring array 3 is as follows: Based on the structure and working principle of the helical antenna, the selection parameters for the detection helical antenna element in this frequency band are calculated: ① Maximum wavelength: ; ② Circumference of the outermost ring: ; ③Outer diameter of the helical antenna: ; For the 2GHz~6GHz frequency band, a 2×16 circular array is used to form the phased array scanning surface, with the array arranged in a rectangular grid on the circumference; for example Figure 7 In the two-dimensional rectangular grid array shown, let the spacing between adjacent antenna elements along the x-axis be . The number of elements is M; the spacing between adjacent antenna elements along the y-axis is... The number of units is N.

[0039] Therefore, the relative positions of the antenna elements are expressed as: Similarly, we perform the same derivation as with the linear array, when the beam direction is... At that time, the matrix factor is: ; in, After normalizing the above equation, we get: ; Therefore, when or Grating lobes will appear. Therefore, we can derive the element spacing requirement for a rectangular grating phased array antenna as follows: ; ; in, and These are the maximum target scanning angles in the xoz and yoz planes, respectively. To achieve the maximum wide-angle target scanning, we take... and Both are 90°, then , Since axial modes are more suitable for radar signal reception, the outer diameter D of the helical antenna in this frequency band can be 60mm, which satisfies the condition of no grating lobes. Therefore, a helical antenna with an outer diameter D of 60mm is selected, according to... If the circumference is evenly distributed, the diameter of the circumference is 0.3m.

[0040] The specific method for calculating the diameter of the 6GHz~18GHz ring array 3 is as follows: Based on the structure and working principle of the helical antenna, the selection parameters for the detection helical antenna element in this frequency band are calculated: ① Maximum wavelength: ; ② Circumference of the outermost ring: ; ③Outer diameter of the helical antenna: ; For the 6GHz~18GHz frequency band, a 4×16 circular array is used to form the phased array scanning surface. The array is arranged in a triangular grid on the circumference.Figure 8 As shown, the antenna elements are arranged in a triangular grid in the xoy plane. The spacing between adjacent elements along the x-axis is... The distance between two adjacent rows of array elements on the y-axis is γ is the base angle of the grid triangle.

[0041] A simple way to synthesize this array is to view it as two rectangular grid arrays placed together, each with an element spacing of [missing information]. The array is structured such that even-numbered rows are considered as a separate antenna array, and odd-numbered rows are considered as a separate antenna array. To achieve a two-dimensional symmetrical structure and scanning range, an equilateral triangular grid is used. Finally, we obtain the requirement that the array should not have grating lobes: ; Therefore, we can deduce that when the same scanning angle is required, the area occupied by the antenna element in each square grid is... , In an equilateral triangular grating, the area occupied by each antenna element is the area of ​​the hexagon shown by the dashed lines above, which is... To achieve the maximum wide-angle scan target, take... If it is 90°, then Since axial modes are more suitable for radar signal reception, the outer diameter D of the helical antenna in this frequency band can be 20mm. At this point, the condition of no grating lobes is met. Therefore, a helical antenna with an outer diameter D of 20mm is selected, and the antenna elements are arranged in a triangular grid with an 8mm interval on the circumference. The diameter of the circumference is 0.16m.

[0042] In summary, after the sixteen Archimedes spiral antennas are arranged into a circular array, the diameters of the three frequency bands of the circular array 3 are 1.6m (0.38GHz~2GHz), 0.3m (2GHz~6GHz), and 0.16m (6GHz~18GHz), respectively, and the height is 0.35m.

[0043] The ultra-wideband receiver 1 includes a limiter 11, a low-noise amplifier 12, a mixer 13, a filter 14, a coupler 15, and a gain-controlled intermediate frequency amplifier 16 connected in sequence. A digitally controlled attenuator 17 is also connected between the limiter 11 and the mixer 13. The ultra-wideband receiver 1 also includes a detector 18, which is electrically connected to the coupler 15.

[0044] The low-noise amplifier 12 and the digitally controlled attenuator 17 are connected to the limiter 11 via a first switch 19, and the low-noise amplifier 12 and the digitally controlled attenuator 17 are connected to the mixer 13 via a second switch 110.

[0045] The digital beamforming processor 2 includes a GPU chip and an FPGA chip, both of which are electrically connected to the ultra-wideband receiver unit 1.

[0046] The GPU chip used is either NVIDIA's RTX 2080 Ti or NVIDIA's GeForce GTX 680 with a stream processor frequency of 1.5GHz. The domestic alternative chips are Jingjia Micro's JM5400 and JM7200.

[0047] The FPGA chip used is the Xilinx Zynq-7000 series FPGA chip or a chip with equivalent performance. The domestic alternative chips are Fudan Microelectronics FMQL45T900 and FMQL45T484.

[0048] The digital beamforming processor 2 adopts a GPU+FPGA architecture. The front-end processor needs to process 1GHz bandwidth signals to complete detection and parameter measurement. The data volume is very large, making real-time processing on the FPGA chip difficult. To improve signal processing speed, a GPU chip is used for multi-channel parallel processing. The GPU chip has extremely high computing power and energy efficiency (up to 1-4 TOPS / W). As a general-purpose computing chip, the GPU chip can simultaneously meet the fast processing needs of traditional algorithms and complex AI algorithms. It also supports signal processing algorithms such as signal monitoring, digital beamforming, and direction finding, as well as target parameter identification and sorting algorithms. The layered software architecture using the general-purpose GPU architecture has strong computing power, standardized software interfaces, software-defined functions, good openness, high intelligence, and easy expansion. The real-time processing software can complete parameter measurement for real-time processing of various signals and generate real-time data through the application of various innovative algorithms.

[0049] The high-bandwidth phased array antenna designed in this scheme adopts a frequency-band processing method, dividing the frequency into three segments. Each band consists of 16 helical antennas, which can achieve instantaneous omnidirectional coverage of 360° in all directions, thereby reducing the aperture effect and improving the performance of the radar system.

[0050] In summary, the phased array antenna provided by this invention controls the selection of signals from a three-band ring array using an ultra-wideband receiver group. The detected signals are then limited, filtered, and down-converted to intermediate frequency (IF) signals. A digital beamforming processor then samples and converts the analog IF signals into digital signals, completing signal detection, search, parameter measurement, and direction-finding beamforming. The ultra-wideband receiver group and digital beamforming processor perform selection, limiting amplification, and network calibration for each RF signal. The ultra-wideband receiver group amplifies the RF signals via repeater amplification to overcome signal attenuation caused by excessive cable length, while simultaneously... The system generates omnidirectional radio frequency signals, performs radio frequency self-tests, and controls functions. The digital beamforming processor enables instantaneous frequency measurement modules and direction-finding circuits across three frequency bands, measuring the frequency and azimuth of each arriving pulse. The high-bandwidth phased array antenna designed in this scheme employs a frequency-band division method, dividing the frequency into three segments. This increases the element size and spacing in the low-frequency band, ensuring antenna gain in the low-frequency band. Combined with an ultra-wideband receiver and digital beamforming processor, it achieves better receiving / transmitting performance in the 0.38GHz-18GHz frequency band, thereby reducing the limitation of phased array radar signal bandwidth caused by aperture crossover.

[0051] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A phased array antenna, characterized in that, It includes an ultra-wideband receiver unit, a digital beamforming processor, and three consecutive ring arrays of frequency bands. The ultra-wideband receiver unit is electrically connected to the digital beamforming processor and the three ring arrays, respectively. The ring array includes four antenna elements. One end of the four antenna elements is arranged at equal intervals on the circumference of the same virtual circle, and the other end of the four antenna elements is located on the four sides of the same virtual square. The center of the virtual square coincides with the center of the virtual circle. The antenna element includes four antenna subarrays that are non-uniformly arranged on the sides of the virtual square. The antenna subarray is tilted and positioned along the edge of the virtual square; The spacing between two adjacent antenna subarrays in the same antenna element increases sequentially in a counterclockwise direction; The antenna subarray is an Archimedes spiral antenna; The frequency bands of the three ring arrays are 0.38GHz~2GHz, 2GHz~6GHz and 6GHz~18GHz, respectively; After the sixteen Archimedes spiral antennas are arranged into a circular array, the diameter of the circular array in the 0.38GHz~2GHz frequency band is 1.6m, the diameter of the circular array in the 2GHz~6GHz frequency band is 0.3m, and the diameter of the circular array in the 6GHz~18GHz frequency band is 0.16m.

2. The phased array antenna according to claim 1, characterized in that, The ultra-wideband receiver unit includes a limiter, a low-noise amplifier, a mixer, a filter, a coupler, and a gain-controlled intermediate frequency amplifier connected in sequence. A digitally controlled attenuator is also connected between the limiter and the mixer. The ultra-wideband receiver unit also includes a detector, which is electrically connected to the coupler.

3. The phased array antenna according to claim 2, characterized in that, The low-noise amplifier and the digitally controlled attenuator are connected to the limiter via a first switch, and the low-noise amplifier and the digitally controlled attenuator are connected to the mixer via a second switch.

4. The phased array antenna according to claim 1, characterized in that, The digital beamforming processor includes a GPU chip and an FPGA chip, both of which are electrically connected to the ultra-wideband receiver unit.

5. The phased array antenna according to claim 1, characterized in that, The ultra-wideband receiver unit is electrically connected to the three ring arrays via a three-to-one signal selection switch.

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