A 128-beam phased array based on 16 / 32 subarray partitioning

Abstract

The application belongs to the technical field of phased array antennas, and particularly relates to a 128-beam phased array based on 16 / 32 subarray division. The phased array is composed of a large-scale antenna array, a reconfigurable subarray division network, a subarray-level processing unit, a global beam synthesis unit, a beam control unit and a calibration unit. The subarray division network supports dynamic configuration of the antenna array into 16 or 32 subarrays, the subarray-level processing unit performs digital beam forming on the signals of each subarray to generate subarray-level beams, the global beam synthesis unit performs secondary synthesis on all the subarray-level beams to obtain 128 independent beams, the beam control unit provides two-stage weighting coefficients, and the calibration unit realizes real-time calibration of channel amplitude and phase. The application realizes optimal balance between hardware complexity and beam forming capability through 16 / 32 subarray flexible switching, and is suitable for large-scale multi-beam application scenarios such as low-orbit satellite communication and radar.

Description

Technical Field

[0001] This invention belongs to the field of phased array antenna technology, specifically involving the subarray partitioning and beamforming design of large-scale multi-beam phased arrays. It is particularly suitable for scenarios requiring large-scale multi-beamforming (128 beams) such as low-Earth orbit satellite communication payloads, ground communication terminals, and radar systems. This phased array utilizes a reconfigurable 16 / 32 subarray partitioning architecture to achieve dynamic switching of subarray modes, balancing gain requirements and beamforming flexibility in different application scenarios. It solves the problem that traditional fixed subarray partitioning cannot adapt to the needs of multiple scenarios and is compatible with the application requirements of mainstream satellite communication frequency bands such as S, Ku, and Ka. Background Technology

[0002] The rapid development of low-Earth orbit satellite communication constellations has placed stringent demands on the large-scale multi-beam capabilities of phased array antennas, with 128 beams and above becoming an industry trend. While all-digital phased arrays can achieve any number of independent beams, each antenna element requires an independent digital channel. When the number of antenna elements reaches hundreds, the system complexity, power consumption, and manufacturing cost increase dramatically, making it difficult to implement in engineering applications.

[0003] Subarray partitioning technology, by dividing a large-scale antenna array into several subarrays and then combining them after subarray-level beamforming, can significantly reduce the number of digital channels, becoming a core technology for large-scale phased arrays. However, existing subarray partitioning schemes all adopt a fixed number of subarrays, which cannot be dynamically adjusted according to the application scenario: large subarray size (few subarrays) has high gain but low beamforming freedom, suitable for long-distance communication; small subarray size (multiple subarrays) has high beam flexibility but lower gain, suitable for complex electromagnetic environments with multiple users. Fixed subarray partitioning cannot meet the performance requirements of different scenarios, becoming a technical bottleneck restricting the multi-scenario adaptability of large-scale multi-beam phased arrays. Summary of the Invention

[0004] The purpose of this invention is to propose a 128-beam phased array based on a 16 / 32 subarray division, which solves the technical problem that the traditional phased array has a fixed subarray division and cannot dynamically adapt to different application scenarios. Through the flexible switching of the 16 / 32 subarray mode, the optimal balance is achieved between hardware complexity, beam gain and beamforming flexibility.

[0005] This phased array includes a large-scale antenna array, a subarray partitioning network, a subarray-level processing unit, a global beamforming unit, a beam control unit, and a calibration unit. The large-scale antenna array contains N≥512 antenna elements, supporting S / Ku / Ka single-band or multi-band common-aperture design to ensure sufficient aperture and gain. The subarray partitioning network is a reconfigurable RF switch matrix, which can dynamically configure the antenna array into 16 or 32 subarrays. The 16-subarray mode uses a 4×8 rectangular partition with 32 elements per subarray, while the 32-subarray mode uses a 4×4 rectangular partition with 16 elements per subarray. The mode switching time is ≤5ms.

[0006] The number of subarray-level processing units matches the number of subarrays and is implemented using FPGA / ASIC. It performs digital down-conversion and weighted summation on the K digital signals from each subarray to generate P subarray-level beams. When M=16, P=8; when M=32, P=4, satisfying the beamforming requirement of M×P=128. The global beamforming unit is implemented using a high-speed DSP, performing secondary weighted synthesis of the M×P subarray-level beam signals to output 128 independent beams. The beam control unit employs a two-level weighting strategy, generating and updating subarray-level and global-level weighting coefficients in real time to adapt to satellite motion and user movement. The calibration unit measures the amplitude-phase inconsistency of the measurement channels, fusing the calibration coefficients with the weighting coefficients to achieve real-time calibration.

[0007] This invention achieves dynamic switching between 16 and 32 subarrays. The 16-subarray mode offers high gain, making it suitable for long-distance communication, while the 32-subarray mode provides high beam flexibility and strong interference suppression capabilities, making it suitable for complex electromagnetic environments. At the same time, it significantly reduces the number of digital channels, lowers the backend processing pressure, and balances system performance, complexity, and adaptability to multiple scenarios. Attached Figure Description

[0008] Figure 1 is a block diagram of the overall architecture of a 128-beam phased array based on a 16 / 32 subarray. Figure 2 is a schematic diagram of the antenna array partitioning structure in the 16-subarray mode; Figure 3 is a schematic diagram of the antenna array partitioning structure in the 32-subarray mode; Figure 4 is a block diagram of the internal structure of the subarray-level processing unit; Figure 5 shows the internal structure of the global beamforming unit. Explanation of reference numerals in the attached figures

[0009] 101: Massive Array 102: Subarray Partitioning Network 103: Subarray-Level Processing Unit 104: Global Beamforming Unit 105: Beam Control Unit 106: Calibration Unit 201: 32×16 rectangular antenna array; 202: 16-subarray pattern subarray; 203: Antenna element. 301: 32×16 rectangular antenna array; 302: 32-subarray pattern subarray; 303: Antenna element. 401: K-channel digital signal input; 402: Digital down-converter module; 403: Beamweighting network; 404: Accumulator; 405: P-channel subarray-level beam output; 406: Control interface 501: M×P subarray-level beam input; 502: Global weighting network; 503: Accumulator array; 504: 128-channel beam output; 505: Synchronization control interface. Detailed Implementation

[0010] The invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale. Furthermore, some well-known parts may not be shown in the drawings.

[0011] Many specific details of the invention, such as array size, operating frequency, and hardware selection, are described below to provide a clearer understanding of the invention. However, as those skilled in the art will understand, the invention may be implemented without following these specific details.

[0012] Figure 1 shows the overall architecture block diagram of a 128-beam phased array based on a 16 / 32 subarray division. As shown in Figure 1, the phased array in this invention includes a massive MIMO antenna array 101, a subarray partitioning network 102, a subarray-level processing unit 103, a global beamforming unit 104, a beam control unit 105, and a calibration unit 106. The massive MIMO antenna array 101 is a 512-element Ka-band microstrip patch array with a working frequency of 30 GHz, an element spacing of 0.5λ, and arranged in a 32×16 rectangular grid. The subarray partitioning network 102 is a PIN diode reconfigurable RF switch matrix that supports dynamic switching between 16 / 32 subarray modes with a switching time ≤5ms. The subarray-level processing unit 103 is an FPGA array, configured with 16 or 32 subarrays, which performs digital beamforming on the signals of each subarray to generate subarray-level beams. The global beamforming unit 104 is a high-speed DSP that performs secondary synthesis on all subarray-level beams, outputting 128 independent beams with a beam coverage range of ±60°. The beam control unit 105 is an ARM Cortex-A9 processor. The processor updates the weighting coefficients every 1ms; the calibration unit 106 has a built-in coupling network and a reference signal source to achieve real-time amplitude and phase calibration of the channels. All modules work together to achieve 16 / 32 subarray mode switching and stable 128-beamformation.

[0013] Figure 2 shows a schematic diagram of the antenna array partitioning structure in the 16-subarray mode. As shown in Figure 2, the 16-subarray mode partitioning in this invention is based on a 32×16 512-element rectangular antenna array 201, which is divided into 16 independent subarrays 202 by thick lines. Each subarray 202 is a 4×8 rectangular structure containing 32 antenna elements 203 with an element spacing of 0.5λ. The 16 subarrays 202 are evenly arranged in a 4×4 array in the 32×16 antenna array 201, with no overlap between subarrays, covering the entire antenna aperture. Each subarray 202 is an independent signal processing unit, connected to the corresponding subarray-level processing unit. In this mode, the subarray scale is large, and the beam gain is about 3dB higher than that of the 32-subarray mode, making it suitable for long-distance satellite communication links.

[0014] Figure 3 shows a schematic diagram of the antenna array partitioning structure in the 32-subarray mode. As shown in Figure 3, the 32-subarray mode partitioning in this invention is based on the same 32×16 512-element rectangular antenna array 301, which is divided into 32 independent subarrays 302 by thick lines. Each subarray 302 is a 4×4 rectangular structure containing 16 antenna elements 303, with the element spacing remaining at 0.5λ. The 32 subarrays 302 are evenly arranged in an 8×4 array within the 32×16 antenna array 301, with no overlap between subarrays, completely covering the antenna aperture. Each subarray 302 is connected to a corresponding subarray-level processing unit. This mode has a large number of subarrays, a high degree of freedom in beamforming, and an interference suppression capability that is about 10dB higher than the 16-subarray mode, making it suitable for multi-user applications in complex electromagnetic environments.

[0015] Figure 4 shows the internal structure block diagram of the subarray-level processing unit. As shown in Figure 4, the subarray-level processing unit in this invention includes K-channel digital signal input 401, a digital down-conversion module 402, a beam weighting network 403, an accumulator 404, P-channel subarray-level beam output 405, and a control interface 406. The number of K-channel digital signal inputs 401 matches the number of subarray units: K=32 when M=16 and K=16 when M=32. The digital down-conversion module 402 performs down-conversion and filtering on the input digital signals to obtain the baseband signal. The beam weighting network 403 receives the weighting coefficients from the beam control unit through the control interface 406 and performs amplitude and phase weighting on the baseband signal. The accumulator 404 sums the weighted signals to generate the subarray-level beam signal. The number of P-channel subarray-level beam outputs 405 matches the mode: P=8 when M=16 and P=4 when M=32. The control interface 406... It enables high-speed data interaction with the beam control unit, and completes coefficient loading and status feedback.

[0016] Figure 5 shows the internal structure block diagram of the global beamforming unit. As shown in Figure 5, the global beamforming unit in this invention includes an M×P subarray-level beam input 501, a global weighting network 502, an accumulator array 503, 128 beam outputs 504, and a synchronization control interface 505. The M×P subarray-level beam input 501 is the output of all subarray-level processing units, with 128 inputs in both 16-subarray and 32-subarray modes. The global weighting network 502 receives the global weighting coefficients from the beam control unit through the synchronization control interface 505 and performs secondary amplitude and phase weighting on the input subarray-level beam signals. The accumulator array 503 contains 128 independent accumulators, which perform parallel summation on the weighted signals to generate 128 independent beam signals. The 128 beam outputs 504 are the final beam signal outputs, meeting the requirements of large-scale multi-beam applications. The synchronization control interface 505 enables synchronous communication with the beam control unit, ensuring real-time updating and loading of the weighting coefficients.

[0017] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the included set of elements (such as a process, method, article, or apparatus) includes not only those elements but also other elements not expressly listed. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements besides those included.

[0018] In this invention, the embodiments do not exhaustively describe all details, nor are they intended to limit the invention to the specific embodiments described. Many variations can be made based on the above description. These embodiments have been selected and specifically described in this specification to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and make modifications based on it. This invention is limited only by the claims and their full scope and equivalents.

Claims

1. A 128-beam phased array based on a 16 / 32 subarray division, characterized in that, It includes a large-scale antenna array, a subarray partitioning network, subarray-level processing units, a global beamforming unit, and a beam control unit. The large-scale antenna array contains N≥512 antenna elements. The subarray partitioning network configures the array into M=16 or 32 subarrays, where M×K≥N. There are M subarray-level processing units, each forming P subarray-level beams with M×P≥128. The global beamforming unit performs secondary synthesis on the M×P subarray-level beams, outputting 128 independent beams. The beam control unit generates and configures the subarray-level and global weighting coefficients.

2. The phased array according to claim 1, characterized in that, When M=16, P=8, and 16×8=128 is selected by the global unit for output; when M=32, P=4, and 32×4=128 is weighted by the global unit for synthesis. The subarray is divided into a reconfigurable RF switch matrix, supporting dynamic switching between 16 / 32 subarray modes.

3. The phased array according to claim 1, characterized in that, The subarray-level processing unit is implemented using FPGA / ASIC and integrates multi-channel digital downconversion, beam weighting and accumulation modules; the global beamforming unit is implemented using high-speed DSP / dedicated beamforming chip and supports 128 beams in parallel computing.

4. The phased array according to claim 1, characterized in that, The beam control unit adopts a two-level weighting strategy. The first level generates the weighting coefficients of the cells within the subarray relative to the phase center of the subarray. The second level generates the weighting coefficients of the phase center of the subarray relative to the phase center of the array. The two levels of coefficients are cascaded to obtain the weighted value of the entire array.

5. The phased array according to claim 1, characterized in that, The large-scale antenna array operates in S / Ku / Ka single-band or multi-band common aperture design. When M=16, the subarray is divided into 4×8 rectangles with 32 elements, and when M=32, the subarray is divided into 4×4 rectangles with 16 elements.

6. The phased array according to claim 1, characterized in that, It also includes a calibration unit, which measures the amplitude-phase inconsistency of each channel, integrates the calibration coefficients with the beam weighting coefficients, and achieves real-time channel calibration to ensure beam quality.

7. The phased array according to claim 1, characterized in that, The number of subarray-level beams P can be dynamically adjusted. When high precision is required, reducing P increases the global synthesis degree of freedom. When low data volume is required, increasing P reduces the number of global synthesis inputs. The mode switching time is ≤5ms.

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