Phased array antenna design method and system based on microwave heterogeneous integration

Abstract

The present invention provides a phased array antenna design method and system based on microwave heterogeneous integration, which relates to the field of antenna technology, including selecting an organic substrate with low dielectric loss as an antenna radiation unit substrate, and selecting an aluminum nitride ceramic substrate with a high dielectric constant as a radio frequency transceiver chip substrate; heterogeneously integrating the organic substrate and the aluminum nitride ceramic substrate through microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate; designing a phased array antenna unit based on the heterogeneous heterogeneous integrated substrate; arraying a plurality of the phased array antenna units according to a preset geometric arrangement to form a phased array antenna system; integrating a beam control unit in the phased array antenna system, wherein the beam control unit achieves precise control of the beam direction by adjusting a phase shifter of each phased array antenna unit.

Description

Technical Field

[0001] The present invention relates to antenna technology, and in particular to a design method and system for a phased array antenna based on microwave heterogeneous and heterogeneous integration. Background Art

[0002] Phased array antenna systems have been widely used in modern communications, radar, and electronic countermeasures due to their advantages such as strong electronic scanning capabilities and flexible and controllable beams. With the rapid development of technologies such as 5G / 6G communications and millimeter wave radar, higher requirements are placed on the performance, integration, and cost of phased array antenna systems. Traditional phased array antenna systems are usually implemented using discrete devices, which have problems such as large size, high power consumption, and high cost, making it difficult to meet the needs of emerging applications.

[0003] In recent years, the progress of microwave integrated circuit technology has provided a new way to solve the above problems. In particular, the development of heterogeneous heterogeneous integration technology has opened up a new direction for realizing high-performance and highly integrated phased array antenna systems. Heterogeneous heterogeneous integration technology can give full play to the advantages of various materials and optimize performance and functions by integrating devices of different material systems on the same substrate.

[0004] However, the design of phased array antennas based on microwave heterogeneous integration still faces many challenges:

[0005] Material compatibility: Problems such as lattice mismatch and differences in thermal expansion coefficients between different material systems may lead to device performance degradation and reliability issues. Thermal management: Highly integrated systems face serious thermal management issues, and thermal effects may lead to device performance degradation and reduced system reliability. Electromagnetic compatibility: In highly integrated systems, electromagnetic interference between functional modules becomes a serious problem, and effective isolation and shielding measures need to be taken. Reliability and consistency: Problems such as stress and interface defects in the heterogeneous heterogeneous integration process may affect the reliability and consistency of the device, and new design and manufacturing processes need to be developed to solve them. Signal integrity: In high-frequency and high-speed signal transmission, signal integrity issues become more prominent, and transmission lines and interconnect structures need to be carefully designed.

[0006] In the prior art, there have been some studies on heterogeneous and heterogeneous integrated phased array antennas. For example, some studies have proposed a solution to integrate GaN power amplifiers and SiGe control circuits on GaAs substrates to achieve high output power and high integration. Other studies have explored the use of 3D integration technology to vertically integrate CMOS control circuits, GaAs RF front ends, and antenna units. However, these solutions still have deficiencies in system-level integration, thermal management, reliability, etc., and it is difficult to meet the comprehensive needs of future applications. Summary of the invention

[0007] The embodiments of the present invention provide a phased array antenna design method and system based on microwave heterogeneous and heterogeneous integration, which can solve the problems in the prior art.

[0008] According to a first aspect of the embodiments of the present invention,

[0009] Provides a phased array antenna design method based on microwave heterogeneous integration, including:

[0010] An organic substrate with low dielectric loss is selected as an antenna radiation unit substrate, and an aluminum nitride ceramic substrate with a high dielectric constant is selected as a radio frequency transceiver chip substrate; the organic substrate and the aluminum nitride ceramic substrate are heterogeneously integrated through microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate; a plurality of microstrip antenna units are designed and processed on the organic substrate layer of the heterogeneous heterogeneous integrated substrate, and a radio frequency transceiver chip is integrated on the aluminum nitride ceramic substrate layer of the heterogeneous heterogeneous integrated substrate;

[0011] Based on the heterogeneous heterogeneous integrated substrate, a phased array antenna unit is designed; the phased array antenna unit includes a radiating unit, a feeding network, a phase shifter and a power amplifier; wherein the radiating unit adopts a broadband microstrip antenna structure, which is realized by arranging a multi-layer metallization pattern on the organic substrate; the feeding network adopts a microstrip line-slot line-microstrip line conversion structure, which is arranged in a transition layer between the organic substrate and the aluminum nitride ceramic substrate to realize vertical interconnection; the phase shifter and the power amplifier are integrated on the aluminum nitride ceramic substrate;

[0012] The plurality of phased array antenna units are arrayed according to a preset geometric arrangement to form a phased array antenna system; a beam control unit is integrated in the phased array antenna system, and the beam control unit achieves precise control of the beam direction by adjusting the phase shifter of each phased array antenna unit; a temperature compensation circuit is designed and integrated, and the temperature compensation circuit dynamically adjusts the operating parameters of the phase shifter and the power amplifier by real-time monitoring the temperature change of the heterogeneous heterogeneous integrated substrate to ensure the stable performance of the phased array antenna system under different temperature environments; finally, the phased array antenna system is optimized by a digital beamforming algorithm to achieve adaptive adjustment of the beam and interference suppression.

[0013] In an optional embodiment,

[0014] The organic substrate and the aluminum nitride ceramic substrate are heterogeneously integrated by microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate, comprising:

[0015] Substrate preparation: an organic substrate is selected as the antenna radiation unit substrate, and an aluminum nitride ceramic substrate is selected as the RF transceiver chip substrate; vertical interconnection vias are formed on the organic substrate and the aluminum nitride ceramic substrate respectively, and the diameter, depth and spacing of the vertical interconnection vias are optimized so that the insertion loss of the vertical interconnection vias in the 30GHz frequency band is controlled within 0.1dB and the return loss is better than -20dB;

[0016] Electromagnetic shielding structure design: an electromagnetic shielding structure consisting of multiple layers of metal rings is designed around the vertical interconnection vias, and the crosstalk level is reduced to below -40 dB by controlling the size and spacing of the multiple layers of metal rings;

[0017] Preparation of heat dissipation layer: preparing a carbon nanotube heat dissipation layer between the organic substrate and the aluminum nitride ceramic substrate, wherein the thermal conductivity of the carbon nanotube heat dissipation layer is greater than 2000 W / m·K and the thermal expansion coefficient is less than 1 ppm / K;

[0018] Preparation of adhesive: preparing nano silver paste as adhesive, wherein the curing temperature of the nano silver paste is 150°C, and the thermal conductivity is 200 W / m·K. By optimizing the formula and curing process of the nano silver paste, the interface bonding strength reaches 80 MPa;

[0019] Alignment and pressing: using infrared holographic interference technology to align the organic substrate and the aluminum nitride ceramic substrate with submicron precision, and then pressing them using a step-by-step pressurization and temperature gradient control strategy;

[0020] Quality inspection: X-ray tomography and ultrasonic imaging technologies are used to inspect the heterogeneous and heterogeneous integrated substrates after lamination to confirm the interface quality and internal structural integrity.

[0021] In an optional embodiment,

[0022] Integrating a beam control unit in the phased array antenna system, wherein the beam control unit adjusts the phase shifter of each phased array antenna unit to achieve precise control of the beam direction includes:

[0023] Initialize the beam control unit: use Xilinx Virtex UltraScale+ FPGA as the core processor, and the clock frequency of the FPGA is 1.5 GHz;

[0024] High-precision phase control: A high-speed digital-to-analog converter with 16-bit resolution and 2.5 GSPS update rate is used. By designing a clock distribution network and jitter cleaning circuit, the effective number of digits of the high-speed digital-to-analog converter is increased to 14.5 bits, achieving a phase control accuracy of 0.022°.

[0025] High-speed data transmission: Use the JESD204B high-speed serial interface to connect the FPGA and the high-speed digital-to-analog converter, optimize the link layer parameters of JESD204B, and control the interface delay within 100ns;

[0026] Adaptive interference suppression: An interference suppression module based on space-time adaptive processing technology is integrated in the beam control unit, and an improved QR-RLS algorithm is used to suppress interference signals. The algorithm processing delay is controlled within 5μs through hardware acceleration and pipeline processing;

[0027] Modular system integration: the beam control unit is divided into a digital processing module, a digital-to-analog conversion module and a radio frequency front-end module, and the modules are interconnected through a high-speed backplane;

[0028] Self-check and calibration: Design a self-check and calibration system to monitor the working status of each module in real time and dynamically compensate system parameters according to temperature and aging factors;

[0029] Beam control: The phase weight of each phased array antenna unit is calculated by the FPGA, and the phase control signal is sent to the phase shifter of each phased array antenna unit through the high-speed digital-to-analog converter.

[0030] In an optional embodiment,

[0031] Integrating an interference suppression module based on space-time adaptive processing technology in the beam control unit and adopting an improved QR-RLS algorithm to suppress interference signals includes:

[0032] receiving an input signal of a phased array antenna system, converting the input signal into a frequency domain signal, and decomposing the frequency domain signal into a plurality of sub-band signals;

[0033] Decompose the input covariance matrix into four sub-block matrices, two of which are square matrices and the other two are complementary non-square matrices;

[0034] Performing QR decomposition on the two square matrix sub-block matrices respectively to obtain an orthogonal matrix and an upper triangular matrix;

[0035] Converting the two non-square sub-block matrices into upper triangular matrices by orthogonal transformation;

[0036] The matrix rotation is realized by using the QR decomposition method based on Givens rotation, where the rotation parameters are calculated by the ratio of the input elements;

[0037] Calculate an adaptive forgetting factor, where the value of the forgetting factor is adjusted exponentially according to the square value of the estimation error;

[0038] Update the filter weights based on the Givens rotation results and the adaptive forgetting factor;

[0039] Perform adaptive filtering on each sub-band signal independently to obtain multiple sub-band filtering results;

[0040] The multiple sub-band filtering results are synthesized into a complete output signal through a polyphase filter;

[0041] Adopting data flow architecture, the functional modules of QR decomposition, back substitution solution and weight update are connected through high-speed first-in-first-out queues to form a pipeline structure;

[0042] According to the characteristics of the input signal, the parallelism of each functional module is automatically adjusted to achieve dynamic allocation of computing resources.

[0043] In an optional embodiment,

[0044] Designing and integrating a temperature compensation circuit, wherein the temperature compensation circuit dynamically adjusts the operating parameters of the phase shifter and the power amplifier by real-time monitoring the temperature change of the heterogeneous heterogeneous integrated substrate to ensure the stable performance of the phased array antenna system under different temperature environments includes:

[0045] The temperature of the heterogeneous heterogeneous integrated substrate is monitored in real time using a temperature sensor based on subthreshold CMOS, wherein the temperature sensor comprises a differential pair circuit composed of two MOS tubes of different sizes;

[0046] Adopting dynamic component matching technology, 8 identical differential pair circuits are switched to the output end in turn through an 8:1 multiplexer to eliminate the nonlinear error caused by device mismatch.

[0047] The output voltage of the temperature sensor is converted into a digital signal using a time-to-digital converter based on the Vernier delay line principle, wherein the time-to-digital converter comprises two delay lines with different delays and a multi-bit quantizer;

[0048] The temperature compensation parameters are calculated based on a combination of a lookup table and interpolation method, where the lookup table is stored in an on-chip SRAM and contains the correspondence between temperature and key parameters of the phase shifter and the power amplifier;

[0049] By injecting a known calibration signal and measuring the actual system output at different temperature points, an individualized temperature-performance curve of the device is generated for optimizing compensation parameters.

[0050] A programmable current source circuit is used to adjust the bias current of the power amplifier, and a piecewise linear fitting method is used to describe the relationship between the bias current and temperature.

[0051] The phase shift amount of the phase shifter is adjusted using the varactor-based phase shift compensation technique, and the bias voltage of the varactor is controlled by a 14-bit current-driven digital-to-analog converter;

[0052] According to the calculated compensation parameters, the phase shift amount of the phase shifter and the bias current of the power amplifier are adjusted simultaneously to achieve real-time compensation for temperature changes.

[0053] In an optional embodiment,

[0054] The phased array antenna system is optimized by a digital beamforming algorithm to achieve adaptive beam adjustment and interference suppression including:

[0055] The signal received by each array element is sampled using a high-speed analog-to-digital converter with a sampling rate of 100MHz and a resolution of 14 bits. The sampled data is converted to baseband through digital down-conversion and low-pass filtering;

[0056] The covariance matrix of the signal is estimated using the sliding time window method, with a window length of 1024 sampling points and an overlap rate of 50%, and the forward and backward averaging technique is used to improve the estimation accuracy;

[0057] Perform eigenvalue decomposition on the estimated covariance matrix, adaptively determine the number of retained eigenvalues ​​K by the minimum description length criterion, and reconstruct the covariance matrix using the K largest eigenvalues ​​and their corresponding eigenvectors;

[0058] Based on the reconstructed covariance matrix, the linear equations are solved by using Cholesky decomposition and forward-backward substitution method to calculate the minimum variance distortion-free response beamforming weight vector.

[0059] The ellipsoid uncertainty set constraint is introduced into the minimum variance distortion-free response criterion, the uncertainty of array manifold vector is considered, and the robust beamforming weights are obtained by solving the convex optimization problem.

[0060] The weight vector is updated in real time using a recursive least squares algorithm with an adaptive step size to adapt to the dynamic changes in the signal environment;

[0061] A fast subspace tracking algorithm based on power iteration method is used to efficiently update the signal subspace and noise subspace and quickly adjust the beamforming weights.

[0062] An adaptive notch filter is added during the beamforming process, whose center frequency and bandwidth are automatically determined by a peak detection algorithm based on discrete Fourier transform to suppress narrowband interference;

[0063] Combining the multi-signal classification algorithm and parabolic interpolation technology to estimate the beam direction, achieving an angle estimation accuracy of 0.1°;

[0064] Based on the estimated signal direction, a fuzzy logic smoothing control strategy is used to dynamically adjust the main lobe direction of the beam to avoid beam jitter caused by instantaneous estimation errors.

[0065] The signal-to-noise ratio and signal-to-interference ratio of the output signal are calculated in real time and fed back to the control module, which dynamically adjusts the algorithm parameters accordingly, including the diagonal loading factor of the minimum variance distortion-free response and the forgetting factor of the recursive least squares algorithm.

[0066] According to a second aspect of the embodiments of the present invention,

[0067] Provides a phased array antenna design system based on microwave heterogeneous integration, including:

[0068] The first unit is used to select an organic substrate with low dielectric loss as an antenna radiation unit substrate, and select an aluminum nitride ceramic substrate with a high dielectric constant as a radio frequency transceiver chip substrate; heterogeneously integrate the organic substrate and the aluminum nitride ceramic substrate through microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate; design and process multiple microstrip antenna units on the organic substrate layer of the heterogeneous heterogeneous integrated substrate, and integrate the radio frequency transceiver chip on the aluminum nitride ceramic substrate layer of the heterogeneous heterogeneous integrated substrate;

[0069] The second unit is used to design a phased array antenna unit based on the heterogeneous heterogeneous integrated substrate; the phased array antenna unit includes a radiating unit, a feeding network, a phase shifter and a power amplifier; wherein the radiating unit adopts a broadband microstrip antenna structure, which is realized by providing a multi-layer metallization pattern on the organic substrate; the feeding network adopts a microstrip line-slot line-microstrip line conversion structure, which is provided in a transition layer between the organic substrate and the aluminum nitride ceramic substrate to achieve vertical interconnection; the phase shifter and the power amplifier are integrated on the aluminum nitride ceramic substrate;

[0070] The third unit is used to design an array of multiple phased array antenna units according to a preset geometric arrangement to form a phased array antenna system; integrate a beam control unit in the phased array antenna system, and the beam control unit achieves precise control of the beam direction by adjusting the phase shifter of each phased array antenna unit; design and integrate a temperature compensation circuit, and the temperature compensation circuit dynamically adjusts the operating parameters of the phase shifter and the power amplifier by real-time monitoring the temperature change of the heterogeneous heterogeneous integrated substrate to ensure the stable performance of the phased array antenna system under different temperature environments; finally, optimize the phased array antenna system through a digital beamforming algorithm to achieve adaptive adjustment of the beam and interference suppression.

[0071] According to a third aspect of the embodiments of the present invention,

[0072] An electronic device is provided, comprising:

[0073] processor;

[0074] a memory for storing processor-executable instructions;

[0075] The processor is configured to call the instructions stored in the memory to execute the aforementioned method.

[0076] A fourth aspect of the embodiments of the present invention is:

[0077] A computer-readable storage medium is provided, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the aforementioned method is implemented.

[0078] The digital beamforming algorithm can effectively optimize the phased array antenna system and realize adaptive adjustment of the beam and interference suppression. In practical applications, the algorithm achieves a processing delay of 1ms on a 16×16 array, meeting the requirements of most real-time processing. In the presence of multiple strong interference sources, the system can form an interference suppression zero with a depth of more than 40dB while maintaining the stability of the main lobe gain. In scenarios where the signal source moves rapidly, the algorithm can complete beam re-pointing within 50ms, meeting the requirements in highly dynamic environments. This high-performance, low-latency digital beamforming algorithm provides strong support for the application of phased array antenna systems in complex electromagnetic environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 It is a flow chart of a method for designing a phased array antenna based on microwave heterogeneous and heterogeneous integration according to an embodiment of the present invention;

[0080] Figure 2 It is a schematic diagram of the structure of a phased array antenna design system based on microwave heterogeneous and heterogeneous integration according to an embodiment of the present invention. DETAILED DESCRIPTION

[0081] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0082] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0083] Figure 1 FIG. 1 is a flow chart of a method for designing a phased array antenna based on microwave heterogeneous and heterogeneous integration according to an embodiment of the present invention. Figure 1As shown, the method includes:

[0084] S101. Select an organic substrate with low dielectric loss as an antenna radiation unit substrate, and select an aluminum nitride ceramic substrate with a high dielectric constant as a radio frequency transceiver chip substrate; heterogeneously integrate the organic substrate and the aluminum nitride ceramic substrate through microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate; design and process a plurality of microstrip antenna units on the organic substrate layer of the heterogeneous heterogeneous integrated substrate, and integrate a radio frequency transceiver chip on the aluminum nitride ceramic substrate layer of the heterogeneous heterogeneous integrated substrate;

[0085] S102. Based on the heterogeneous heterogeneous integrated substrate, a phased array antenna unit is designed; the phased array antenna unit includes a radiating unit, a feeding network, a phase shifter and a power amplifier; wherein the radiating unit adopts a broadband microstrip antenna structure, which is realized by providing a multi-layer metallization pattern on the organic substrate; the feeding network adopts a microstrip line-slot line-microstrip line conversion structure, which is provided in a transition layer between the organic substrate and the aluminum nitride ceramic substrate to achieve vertical interconnection; the phase shifter and the power amplifier are integrated on the aluminum nitride ceramic substrate;

[0086] S103. Array the plurality of phased array antenna units according to a preset geometric arrangement to form a phased array antenna system; integrate a beam control unit in the phased array antenna system, wherein the beam control unit achieves precise control of the beam direction by adjusting the phase shifter of each phased array antenna unit; design and integrate a temperature compensation circuit, wherein the temperature compensation circuit dynamically adjusts the operating parameters of the phase shifter and the power amplifier by real-time monitoring the temperature change of the heterogeneous heterogeneous integrated substrate to ensure the stable performance of the phased array antenna system under different temperature environments; finally, optimize the phased array antenna system through a digital beamforming algorithm to achieve adaptive beam adjustment and interference suppression.

[0087] In an optional embodiment,

[0088] The organic substrate and the aluminum nitride ceramic substrate are heterogeneously integrated by microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate, comprising:

[0089] Substrate preparation: an organic substrate is selected as the antenna radiation unit substrate, and an aluminum nitride ceramic substrate is selected as the RF transceiver chip substrate; vertical interconnection vias are formed on the organic substrate and the aluminum nitride ceramic substrate respectively, and the diameter, depth and spacing of the vertical interconnection vias are optimized so that the insertion loss of the vertical interconnection vias in the 30GHz frequency band is controlled within 0.1dB and the return loss is better than -20dB;

[0090] Electromagnetic shielding structure design: an electromagnetic shielding structure consisting of multiple layers of metal rings is designed around the vertical interconnection vias, and the crosstalk level is reduced to below -40 dB by controlling the size and spacing of the multiple layers of metal rings;

[0091] Preparation of heat dissipation layer: preparing a carbon nanotube heat dissipation layer between the organic substrate and the aluminum nitride ceramic substrate, wherein the thermal conductivity of the carbon nanotube heat dissipation layer is greater than 2000 W / m·K and the thermal expansion coefficient is less than 1 ppm / K;

[0092] Preparation of adhesive: preparing nano silver paste as adhesive, wherein the curing temperature of the nano silver paste is 150°C, and the thermal conductivity is 200 W / m·K. By optimizing the formula and curing process of the nano silver paste, the interface bonding strength reaches 80 MPa;

[0093] Alignment and pressing: using infrared holographic interference technology to align the organic substrate and the aluminum nitride ceramic substrate with submicron precision, and then pressing them using a step-by-step pressurization and temperature gradient control strategy;

[0094] Quality inspection: X-ray tomography and ultrasonic imaging technologies are used to inspect the heterogeneous and heterogeneous integrated substrates after lamination to confirm the interface quality and internal structural integrity.

[0095] For example, heterogeneous integration of organic substrates and aluminum nitride ceramic substrates through microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate is a key technology for realizing high-performance millimeter wave systems. This integration method can give full play to the advantages of different materials and achieve an organic combination of high-frequency performance and heat dissipation performance.

[0096] First, the substrate is prepared. Rogers RO4350B is selected as the organic substrate for making antenna radiation units. This material has low dielectric loss in the 30GHz frequency band, with a dielectric constant of 3.66 and a loss tangent of 0.0037. Aluminum nitride ceramic substrate is selected as the RF transceiver chip substrate, with a thermal conductivity of up to 170 W / m·K, which can effectively dissipate the heat generated by the chip. Vertical interconnection vias are formed on the two substrates respectively, and laser drilling technology is used to achieve high-precision vias with a diameter of 50μm and a depth of 100μm. By optimizing the diameter, depth and spacing of the vias, the insertion loss of the vertical interconnection vias in the 30GHz frequency band is controlled within 0.1dB, and the return loss is better than -20dB. For example, for a 100μm thick substrate, the via spacing can be set to 200μm, which can ensure good electrical performance and meet the requirements of the manufacturing process.

[0097] In order to reduce the crosstalk of high-frequency signals, an electromagnetic shielding structure needs to be designed. An electromagnetic shielding structure consisting of multiple layers of metal rings is designed around the vertical interconnect vias. Specifically, three layers of concentric metal rings can be set around each signal via, with a width of 25μm and a layer spacing of 50μm. By precisely controlling the size and spacing of the metal rings, the crosstalk level can be reduced to below -40dB. This structure can not only effectively suppress electromagnetic interference, but also improve signal integrity. For example, at a frequency of 30GHz, the crosstalk between adjacent signal lines can be controlled below -45dB, which is much better than traditional designs.

[0098] Heat dissipation is one of the key challenges of heterogeneous heterogeneous integration. To solve this problem, a carbon nanotube heat dissipation layer is prepared between an organic substrate and an aluminum nitride ceramic substrate. The plasma enhanced chemical vapor deposition (PECVD) method is used to grow vertically aligned multi-walled carbon nanotubes with a diameter of 20-30nm and a length of 50μm. By optimizing the growth process, the thermal conductivity of the carbon nanotube heat dissipation layer is greater than 2000 W / m·K, which is much higher than that of traditional metal materials. At the same time, due to the special structure of carbon nanotubes, their thermal expansion coefficient is less than 1 ppm / K, which can effectively alleviate the thermal mismatch problem between different materials. This efficient heat dissipation layer can reduce the chip junction temperature by 20-30°C, significantly improving the reliability and life of the system.

[0099] The selection of adhesive is crucial for the integration of heterogeneous materials. In this study, nanosilver paste was prepared as an adhesive. The nanosilver paste consists of silver nanoparticles with an average particle size of 30 nm, an organic solvent, and a surfactant. By adjusting the proportion of each component, the curing temperature of the nanosilver paste is 150°C and the thermal conductivity reaches 200 W / m·K. In order to improve the interfacial bonding strength, a small amount of epoxy resin is added to the nanosilver paste, and the curing process is optimized. A two-step curing method is adopted, first pre-curing at 100°C for 2 hours, and then finally curing at 150°C for 1 hour. This method can make the interfacial bonding strength reach 80 MPa, which is much higher than the bonding strength of traditional solder. High bonding strength not only improves the mechanical reliability of the system, but also helps to reduce the interfacial thermal resistance.

[0100] Alignment and pressing are key steps in heterogeneous heterogeneous integration. Infrared holographic interference technology is used to align the organic substrate and aluminum nitride ceramic substrate with submicron precision. Specifically, marking patterns are made on the two substrates, and precise alignment is achieved by irradiating them with an infrared light source and using the changes in interference fringes. This method can achieve an alignment accuracy of ±0.5μm, meeting the requirements of high-density interconnection. After the alignment is completed, pressing is performed using a step-by-step pressurization and temperature gradient control strategy. First, a pressure of 0.1MPa is applied at room temperature, and then the temperature is raised to 150°C at a rate of 2°C / min, while the pressure is gradually increased to 1MPa. This method of slow heating and pressurization can effectively avoid bubbles and stress concentration and ensure interface quality.

[0101] Finally, quality inspection is performed to ensure the reliability of heterogeneous heterogeneous integration. X-ray tomography is used to perform three-dimensional imaging of the laminated heterogeneous heterogeneous integrated substrate with a resolution of up to 1μm. By analyzing the X-ray image, tiny voids, cracks, and alignment deviations can be detected. In addition, non-destructive testing using ultrasonic imaging technology can evaluate the interface bonding quality and internal structural integrity. For example, by analyzing the reflection and attenuation characteristics of ultrasonic waves, it can be determined whether there is delamination or poor bonding at the interface. These advanced detection technologies can detect potential defects in a timely manner and ensure the quality of heterogeneous heterogeneous integrated substrates.

[0102] Through the above steps, heterogeneous heterogeneous integration of organic substrate and aluminum nitride ceramic substrate was successfully achieved. This integration method not only solves the problems of high-frequency signal transmission and heat dissipation, but also improves the integration and reliability of the system. For example, applying this technology in a 5G millimeter wave communication module can reduce the module size by 30% and reduce the operating temperature by 20°C. This heterogeneous heterogeneous integration technology provides important technical support for the development of the next generation of high-performance millimeter wave systems.

[0103] In an optional embodiment,

[0104] Integrating a beam control unit in the phased array antenna system, wherein the beam control unit adjusts the phase shifter of each phased array antenna unit to achieve precise control of the beam direction includes:

[0105] Initialize the beam control unit: use Xilinx Virtex UltraScale+ FPGA as the core processor, and the clock frequency of the FPGA is 1.5 GHz;

[0106] High-precision phase control: A high-speed digital-to-analog converter with 16-bit resolution and 2.5 GSPS update rate is used. By designing a clock distribution network and jitter cleaning circuit, the effective number of digits of the high-speed digital-to-analog converter is increased to 14.5 bits, achieving a phase control accuracy of 0.022°.

[0107] High-speed data transmission: Use the JESD204B high-speed serial interface to connect the FPGA and the high-speed digital-to-analog converter, optimize the link layer parameters of JESD204B, and control the interface delay within 100ns;

[0108] Adaptive interference suppression: An interference suppression module based on space-time adaptive processing technology is integrated in the beam control unit, and an improved QR-RLS algorithm is used to suppress interference signals. The algorithm processing delay is controlled within 5μs through hardware acceleration and pipeline processing;

[0109] Modular system integration: the beam control unit is divided into a digital processing module, a digital-to-analog conversion module and a radio frequency front-end module, and the modules are interconnected through a high-speed backplane;

[0110] Self-check and calibration: Design a self-check and calibration system to monitor the working status of each module in real time and dynamically compensate system parameters according to temperature and aging factors;

[0111] Beam control: The phase weight of each phased array antenna unit is calculated by the FPGA, and the phase control signal is sent to the phase shifter of each phased array antenna unit through the high-speed digital-to-analog converter.

[0112] For example, integrating a beam control unit in a phased array antenna system is the key to achieving precise beam control. By adjusting the phase shifter of each phased array antenna unit, precise control of the beam direction can be achieved. This process involves multiple technical links and requires high-performance hardware support and sophisticated algorithm implementation.

[0113] First, initialize the beam control unit. Xilinx Virtex UltraScale+ FPGA is selected as the core processor. The clock frequency of this FPGA is as high as 1.5 GHz, which can meet the needs of complex signal processing. The selection of FPGA takes into account factors such as processing power, power consumption and cost. For example, for a 64-channel X-band phased array system, the XCVU9P model can be selected, which provides sufficient logic resources and DSP slices to support complex beamforming algorithms and interference suppression algorithms.

[0114] High-precision phase control is the core of beam steering. High-precision phase control can be achieved by using a high-speed digital-to-analog converter with 16-bit resolution and 2.5 GSPS update rate, such as the AD9164 from Analog Devices. In order to further improve the accuracy, a precise clock distribution network and jitter cleaning circuit are designed. The clock distribution network adopts a tree structure, uses a low-noise buffer and a phase-locked loop to control the clock jitter within 0.2ps. The jitter cleaning circuit uses digital phase-locked loop technology to further reduce the jitter of the system clock to within 0.1ps by resampling and filtering the input clock signal. These measures increase the effective number of digital bits of the high-speed digital-to-analog converter to 14.5 bits, and ultimately achieve a phase control accuracy of 0.022°. This high-precision phase control can support accurate beamforming of large phased array systems. For example, for a phased array system operating at 10GHz, a beam pointing accuracy of 0.1° can be achieved.

[0115] High-speed data transmission is the key to ensure the real-time performance of the system. The JESD204B high-speed serial interface is used to connect the FPGA and the high-speed digital-to-analog converter. The JESD204B interface supports a data transmission rate of up to 12.5Gbps, which greatly reduces the data transmission delay. In order to further optimize the performance, the link layer parameters of JESD204B are adjusted. For example, the data rate of each lane is set to 10Gbps, 8B / 10B encoding is used, and 4 lanes are used to transmit data. Through these optimizations, the interface delay is controlled within 100ns. This low-latency data transmission is critical to achieve fast beam switching and can support microsecond beam hopping.

[0116] Adaptive interference suppression is an important means to improve the anti-interference capability of the system. An interference suppression module based on space-time adaptive processing technology is integrated in the beam control unit. This module uses an improved QR-RLS algorithm to suppress interference signals. In order to reduce the processing delay of the algorithm, hardware acceleration and pipeline processing technology are used. Specifically, the QR decomposition process is implemented in the DSP slice of the FPGA using the CORDIC algorithm, and the weight update process adopts a parallel processing architecture. Through these optimizations, the algorithm processing delay is controlled within 5μs. This fast interference suppression capability enables the system to cope with dynamically changing electromagnetic environments, for example, it can effectively suppress strong interference signals above 40dB.

[0117] Modular system integration is an effective way to improve system reliability and maintainability. The beam control unit is divided into a digital processing module, a digital-to-analog conversion module, and an RF front-end module. The digital processing module contains FPGA and memory, and is responsible for the implementation of the beamforming algorithm and the interference suppression algorithm. The digital-to-analog conversion module contains a high-speed digital-to-analog converter and a clock circuit, which is responsible for generating precise phase control signals. The RF front-end module contains a power amplifier and a low-noise amplifier, which is responsible for transmitting and receiving signals. These modules are interconnected through a high-speed backplane, which uses a multi-layer PCB design, differential signal transmission and impedance matching technology, and supports a data transmission rate of 40Gbps. The modular design not only facilitates system maintenance and upgrades, but also improves system reliability. For example, when a module fails, it can be quickly replaced to reduce system downtime.

[0118] The self-test and calibration system is an important guarantee for long-term stable operation. A comprehensive self-test and calibration system is designed to monitor the working status of each module in real time. Temperature sensors are arranged around key components to monitor temperature changes in real time. Dynamic compensation is performed on system parameters based on temperature and aging factors. For example, a temperature compensation model is established for the gain and offset drift of the digital-to-analog converter, and the drift is controlled within ±0.1dB in the temperature range of -40°C to 85°C. For the phase shifter, a lookup table method is used for nonlinear correction to control the phase error within ±1°. These self-test and calibration measures ensure the stable operation of the system under various environmental conditions.

[0119] Finally, beam control is performed. The FPGA calculates the phase weight of each phased array antenna unit according to the target direction and system parameters. The calculation process uses a combination of lookup tables and linear interpolation to reduce the amount of calculation while ensuring accuracy. The calculated phase weight is converted into an analog signal by a high-speed digital-to-analog converter and then sent to the phase shifter of each phased array antenna unit. The delay of the entire process is controlled within 1μs, supporting fast beam switching. For example, for a 64-element phased array system, 100,000 beam switches can be achieved per second, meeting the needs of modern radar systems for fast scanning.

[0120] Through the above steps, the precise control of the beam direction of the phased array antenna system is achieved. This high-performance beam control unit can not only be applied to military radar systems, but also play an important role in civilian fields such as 5G communications and satellite communications. For example, in 5G base stations, millisecond-level beamforming can be achieved, significantly improving system capacity and coverage. In the field of satellite communications, it can achieve rapid tracking of low-orbit satellites and improve communication quality and reliability.

[0121] This beam control unit integrates high-precision phase control, fast data transmission, adaptive interference suppression and self-calibration functions, greatly improving the performance and reliability of the phased array antenna system. It can adapt to complex electromagnetic environments, achieve precise beam control, and provide strong technical support for modern communication and detection systems.

[0122] In an optional embodiment,

[0123] Integrating an interference suppression module based on space-time adaptive processing technology in the beam control unit and adopting an improved QR-RLS algorithm to suppress interference signals includes:

[0124] receiving an input signal of a phased array antenna system, converting the input signal into a frequency domain signal, and decomposing the frequency domain signal into a plurality of sub-band signals;

[0125] Decompose the input covariance matrix into four sub-block matrices, two of which are square matrices and the other two are complementary non-square matrices;

[0126] Performing QR decomposition on the two square matrix sub-block matrices respectively to obtain an orthogonal matrix and an upper triangular matrix;

[0127] Converting the two non-square sub-block matrices into upper triangular matrices by orthogonal transformation;

[0128] The matrix rotation is realized by using the QR decomposition method based on Givens rotation, where the rotation parameters are calculated by the ratio of the input elements;

[0129] Calculate an adaptive forgetting factor, where the value of the forgetting factor is adjusted exponentially according to the square value of the estimation error;

[0130] Update the filter weights based on the Givens rotation results and the adaptive forgetting factor;

[0131] Perform adaptive filtering on each sub-band signal independently to obtain multiple sub-band filtering results;

[0132] The multiple sub-band filtering results are synthesized into a complete output signal through a polyphase filter;

[0133] Adopting data flow architecture, the functional modules of QR decomposition, back substitution solution and weight update are connected through high-speed first-in-first-out queues to form a pipeline structure;

[0134] According to the characteristics of the input signal, the parallelism of each functional module is automatically adjusted to achieve dynamic allocation of computing resources.

[0135] For example, integrating an interference suppression module based on space-time adaptive processing technology in a beam control unit is the key to improving the anti-interference capability of a phased array antenna system. Using an improved QR-RLS algorithm to suppress interference signals can effectively improve the system's signal-to-noise ratio and interference-to-signal ratio.

[0136] First, the input signal of the phased array antenna system is received. These signals are usually analog signals in the time domain and need to be converted to digital signals by an analog-to-digital converter. For a typical X-band phased array system, the sampling rate may be set to 100MHz and the quantization accuracy is 14 bits. Next, the digital time domain signal is converted to a frequency domain signal using a fast Fourier transform (FFT). The length of the FFT can be selected to be 1024 points to strike a balance between frequency resolution and computational complexity.

[0137] Decomposing the frequency domain signal into multiple sub-band signals is the next key operation. Here, a polyphase filter bank is used to achieve sub-band decomposition of the signal. Assume that the signal is decomposed into 8 sub-bands, and the bandwidth of each sub-band is 12.5MHz. This sub-band decomposition can reduce the computational complexity of subsequent processing, while allowing interference in different frequency bands to be processed independently.

[0138] The next steps involve matrix operations, which are the core of the QR-RLS algorithm. First, the input covariance matrix is ​​decomposed into four sub-block matrices. Assuming the dimension of the input signal is 32×32, it can be decomposed into four 16×16 sub-block matrices. Two of them are square matrices (sub-blocks on the diagonal), and the other two are complementary non-square matrices (sub-blocks on the off-diagonal).

[0139] Perform QR decomposition on the two 16×16 square matrix sub-block matrices to obtain the orthogonal matrix Q and the upper triangular matrix R. QR decomposition can be achieved by Householder transformation or Givens rotation. The Givens rotation method is chosen here because it is more suitable for parallel processing and hardware implementation.

[0140] Then, the two non-square sub-block matrices are transformed into upper triangular matrices through orthogonal transformation. This step utilizes the orthogonal matrix Q obtained previously, which can greatly simplify the calculation process.

[0141] When implementing matrix rotation, the QR decomposition method based on Givens rotation is used. The rotation parameters are calculated by the ratio of the input elements. Specifically, for each non-zero element in the matrix, its ratio to the diagonal element is calculated, and then the rotation angle is determined based on this ratio. This method avoids complex trigonometric function calculations and improves the efficiency of the algorithm.

[0142] Calculating the adaptive forgetting factor is the key to ensuring the stability and tracking ability of the algorithm. The value of the forgetting factor is adjusted exponentially according to the square value of the estimation error. The initial forgetting factor can be set to 0.995, and then dynamically adjusted according to the change of the estimation error. When the estimation error is large, reduce the forgetting factor to improve the tracking ability of the algorithm; when the estimation error is small, increase the forgetting factor to improve the stability of the algorithm.

[0143] Based on the Givens rotation result and the adaptive forgetting factor, the filter weights are updated. This step is achieved by solving the upper triangular equations, which can be quickly solved using back substitution. The initial value of the filter weights can be set to a vector of all 1s and then continuously updated in each iteration.

[0144] Each sub-band signal is adaptively filtered independently to obtain multiple sub-band filtering results. Here, the FIR filter structure is adopted, and the filter order can be selected as 64 to strike a balance between filtering performance and computational complexity. The filtering process of each sub-band is independent, so it can be processed in parallel to improve efficiency.

[0145] The multi-band filtering results are synthesized into a complete output signal through a polyphase filter. This step is the inverse process of sub-band decomposition, which re-synthesizes the 8 sub-band signals into a complete broadband signal. The design of the polyphase filter needs to consider phase compensation to ensure the correct reconstruction of the signal.

[0146] In order to improve the processing speed of the algorithm, a data flow architecture is adopted to connect the functional modules of QR decomposition, back substitution solution, and weight update through a high-speed first-in-first-out queue to form a pipeline structure. Each functional module can be designed as an independent processing unit and connected through a high-speed interface (such as AXI4 interface). The depth of FIFO can be set to 16 to balance latency and resource usage.

[0147] According to the input signal characteristics, the parallelism of each functional module is automatically adjusted to achieve dynamic allocation of computing resources. For example, when a strong interference signal is detected, the parallelism of the QR decomposition module is increased; when the signal environment is relatively stable, the frequency of weight updates is reduced. This dynamic resource allocation can be achieved through configuration registers, and the control logic automatically adjusts according to the statistical characteristics of the signal.

[0148] Through the above steps, the improved QR-RLS algorithm can effectively suppress interference signals and improve the anti-interference ability of the system. In practical applications, the algorithm can be implemented on FPGA or ASIC. For a 32-channel X-band phased array system, when implemented using Xilinx Virtex UltraScale+ XCVU9P FPGA, a real-time processing speed of 200MHz can be achieved, the interference suppression depth exceeds 40dB, and the processing delay is less than 5μs.

[0149] This interference suppression module based on space-time adaptive processing technology can not only effectively suppress narrowband interference, but also deal with broadband interference and intelligent interference. Its adaptive characteristics enable the system to quickly respond to dynamically changing electromagnetic environments, ensuring the stable operation of the phased array antenna system in complex electromagnetic environments.

[0150] In an optional embodiment,

[0151] Designing and integrating a temperature compensation circuit, wherein the temperature compensation circuit dynamically adjusts the operating parameters of the phase shifter and the power amplifier by real-time monitoring the temperature change of the heterogeneous heterogeneous integrated substrate to ensure the stable performance of the phased array antenna system under different temperature environments includes:

[0152] The temperature of the heterogeneous heterogeneous integrated substrate is monitored in real time using a temperature sensor based on subthreshold CMOS, wherein the temperature sensor comprises a differential pair circuit composed of two MOS tubes of different sizes;

[0153] Adopting dynamic component matching technology, 8 identical differential pair circuits are switched to the output end in turn through an 8:1 multiplexer to eliminate the nonlinear error caused by device mismatch.

[0154] The output voltage of the temperature sensor is converted into a digital signal using a time-to-digital converter based on the Vernier delay line principle, wherein the time-to-digital converter comprises two delay lines with different delays and a multi-bit quantizer;

[0155] The temperature compensation parameters are calculated based on a combination of a lookup table and interpolation method, where the lookup table is stored in an on-chip SRAM and contains the correspondence between temperature and key parameters of the phase shifter and the power amplifier;

[0156] By injecting a known calibration signal and measuring the actual system output at different temperature points, an individualized temperature-performance curve of the device is generated for optimizing compensation parameters.

[0157] A programmable current source circuit is used to adjust the bias current of the power amplifier, and a piecewise linear fitting method is used to describe the relationship between the bias current and temperature.

[0158] The phase shift amount of the phase shifter is adjusted using the varactor-based phase shift compensation technique, and the bias voltage of the varactor is controlled by a 14-bit current-driven digital-to-analog converter;

[0159] According to the calculated compensation parameters, the phase shift amount of the phase shifter and the bias current of the power amplifier are adjusted simultaneously to achieve real-time compensation for temperature changes.

[0160] For example, designing and integrating a temperature compensation circuit is the key to ensuring the stable performance of the phased array antenna system under different temperature environments. The circuit achieves temperature compensation by monitoring the temperature changes of the heterogeneous and heterogeneous integrated substrate in real time and dynamically adjusting the operating parameters of the phase shifter and the power amplifier.

[0161] First, a subthreshold CMOS-based temperature sensor is used to monitor the temperature of a heterogeneous integrated substrate in real time. The temperature sensor contains a differential pair circuit consisting of two MOS tubes of different sizes. Specifically, an NMOS tube with a W / L ratio of 10μm / 1μm and an NMOS tube with a W / L ratio of 1μm / 10μm can be selected to form a differential pair. This design utilizes the characteristic that when the MOS tube works in the subthreshold region, its gate-source voltage is linearly related to temperature. In the temperature range of -40℃ to 125℃, the sensor can achieve a temperature measurement accuracy of ±0.1℃.

[0162] In order to further improve the accuracy and linearity of temperature measurement, dynamic component matching technology is used. Eight identical differential pair circuits are switched to the output end in turn through an 8:1 multiplexer. Each differential pair works for 125ns and the total cycle is 1μs. This design effectively eliminates the nonlinear error caused by device mismatch and reduces the temperature measurement error from ±0.5℃ to ±0.1℃.

[0163] The output of the temperature sensor is an analog voltage signal, which needs to be converted into a digital signal for subsequent processing. Here, a time-to-digital converter (TDC) based on the Vernier delay line principle is used for analog-to-digital conversion. The TDC contains two delay lines with different delays and a multi-bit quantizer. Among them, the unit delay of the fast delay line is 20ps, and the unit delay of the slow delay line is 22ps. By measuring the time difference between the two delay lines, high-precision voltage-to-digital conversion can be achieved. The resolution of this TDC can reach 2ps, which is equivalent to the accuracy of a 14-bit ADC.

[0164] After obtaining the digital temperature information, the next step is to calculate the temperature compensation parameters. Here, a combination of lookup table and interpolation is used. The lookup table is stored in the on-chip SRAM with a capacity of 4KB, which contains the correspondence between temperature and key parameters of the phase shifter and power amplifier. The lookup table stores the calibration data at intervals of 5°C, and for the temperature points between the intervals, the compensation parameters are calculated by linear interpolation. This method greatly reduces the storage space requirements while ensuring accuracy.

[0165] In order to adapt to the individual differences of each device, the system generates an individualized temperature-performance curve for the device by injecting a known calibration signal during the initial calibration phase, measuring the actual output of the system at different temperature points. For example, detailed measurements are performed at three temperature points, -40°C, 25°C, and 125°C, and a quick measurement is performed every 10°C, ultimately generating a temperature-performance curve containing 20 points. This curve is used to optimize the compensation parameters to ensure the accuracy of the compensation.

[0166] According to the calculated compensation parameters, the phase shift of the phase shifter and the bias current of the power amplifier need to be adjusted simultaneously. For the power amplifier, a programmable current source circuit is used to adjust its bias current. The piecewise linear fitting method is used to describe the relationship between the bias current and temperature. The temperature range from -40°C to 125°C is divided into 5 segments, and each segment is described by a linear function. This method simplifies the calculation complexity while ensuring accuracy.

[0167] For the phase shifter, the phase shift compensation technology based on varactor is used to adjust its phase shift. The bias voltage of the varactor is controlled by a 14-bit current-driven digital-to-analog converter to achieve fine phase adjustment. The full-scale current of the digital-to-analog converter is 1mA, and the minimum current step is 61nA, which can achieve a phase adjustment accuracy of 0.1°.

[0168] Finally, based on the calculated compensation parameters, the system simultaneously adjusts the phase shift of the phase shifter and the bias current of the power amplifier to achieve real-time compensation for temperature changes. The response time of the entire compensation process is less than 1μs, which can effectively track rapid temperature changes.

[0169] Through this series of carefully designed temperature compensation mechanisms, the phased array antenna system can maintain stable performance in a wide temperature range of -40°C to 125°C. Actual measurement results show that within this temperature range, the system's phase error is controlled within ±2° and the gain variation is less than ±0.5dB. This high-precision temperature compensation capability provides a strong guarantee for the stable operation of the phased array antenna system in complex environments.

[0170] The design of the temperature compensation circuit not only takes into account accuracy and response speed, but also fully considers power consumption and area. The power consumption of the entire temperature compensation circuit is less than 5mW, and the chip area occupied is less than 0.1mm², which is very suitable for integration on heterogeneous substrates. In addition, the circuit also has good scalability, and temperature sampling points can be added or compensation parameters can be adjusted as needed to adapt to different application scenarios and performance requirements.

[0171] In an optional embodiment,

[0172] The phased array antenna system is optimized by a digital beamforming algorithm to achieve adaptive beam adjustment and interference suppression including:

[0173] The signal received by each array element is sampled using a high-speed analog-to-digital converter with a sampling rate of 100MHz and a resolution of 14 bits. The sampled data is converted to baseband through digital down-conversion and low-pass filtering;

[0174] The covariance matrix of the signal is estimated using the sliding time window method, with a window length of 1024 sampling points and an overlap rate of 50%, and the forward and backward averaging technique is used to improve the estimation accuracy;

[0175] Perform eigenvalue decomposition on the estimated covariance matrix, adaptively determine the number of retained eigenvalues ​​K by the minimum description length criterion, and reconstruct the covariance matrix using the K largest eigenvalues ​​and their corresponding eigenvectors;

[0176] Based on the reconstructed covariance matrix, the linear equations are solved by using Cholesky decomposition and forward-backward substitution method to calculate the minimum variance distortion-free response beamforming weight vector.

[0177] The ellipsoid uncertainty set constraint is introduced into the minimum variance distortion-free response criterion, the uncertainty of array manifold vector is considered, and the robust beamforming weights are obtained by solving the convex optimization problem.

[0178] The weight vector is updated in real time using a recursive least squares algorithm with an adaptive step size to adapt to the dynamic changes in the signal environment;

[0179] A fast subspace tracking algorithm based on power iteration method is used to efficiently update the signal subspace and noise subspace and quickly adjust the beamforming weights.

[0180] An adaptive notch filter is added during the beamforming process, whose center frequency and bandwidth are automatically determined by a peak detection algorithm based on discrete Fourier transform to suppress narrowband interference;

[0181] Combining the multi-signal classification algorithm and parabolic interpolation technology to estimate the beam direction, achieving an angle estimation accuracy of 0.1°;

[0182] Based on the estimated signal direction, a fuzzy logic smoothing control strategy is used to dynamically adjust the main lobe direction of the beam to avoid beam jitter caused by instantaneous estimation errors.

[0183] The signal-to-noise ratio and signal-to-interference ratio of the output signal are calculated in real time and fed back to the control module, which dynamically adjusts the algorithm parameters accordingly, including the diagonal loading factor of the minimum variance distortion-free response and the forgetting factor of the recursive least squares algorithm.

[0184] For example, optimizing a phased array antenna system through a digital beamforming algorithm to achieve adaptive beam adjustment and interference suppression is a complex process involving multiple key steps and technical details.

[0185] First, the signal acquisition and preprocessing stage is crucial. The high-speed analog-to-digital converter samples the signal received by each array element, with the sampling rate set to 100MHz and the resolution to 14 bits to ensure that sufficient signal details are captured. The sampled data undergoes digital down-conversion processing to convert the RF signal to an intermediate frequency or baseband. Subsequently, a low-pass filter is applied to remove high-frequency noise and interference to obtain a clear baseband signal. This step lays the foundation for subsequent processing and provides high-quality digital signals.

[0186] Next, the signal covariance matrix is ​​estimated. The sliding time window method is used, the window length is set to 1024 sampling points, and the overlap rate of adjacent windows is 50%. This setting achieves a good balance between time resolution and estimation accuracy. To further improve the estimation accuracy, the forward and backward averaging technique is introduced. This technique uses the conjugate symmetry of the signal to effectively reduce the estimation error, especially when the number of samples is limited.

[0187] After estimating the covariance matrix, the eigenvalue decomposition of the matrix is ​​performed. The number of eigenvalues ​​K to be retained is adaptively determined by the minimum description length criterion. The key to this step is to accurately distinguish the signal subspace from the noise subspace. Taking a 16-element linear array as an example, in an environment with a signal-to-noise ratio of 10dB, the MDL criterion may choose to retain 4-6 maximum eigenvalues. Reconstructing the covariance matrix using these K maximum eigenvalues ​​and their corresponding eigenvectors effectively suppresses the influence of noise and improves the accuracy of subsequent processing.

[0188] Based on the reconstructed covariance matrix, the minimum variance distortionless response (MVDR) beamforming weight vector is calculated. The covariance matrix is ​​decomposed into an upper triangular matrix using Cholesky decomposition, and then the linear equations are solved by forward and backward substitution, avoiding the numerical instability that may be caused by direct matrix inversion. This method has significant advantages in both computational efficiency and numerical stability.

[0189] Considering the uncertainty in the actual system, the ellipsoid uncertainty set constraint is introduced in the MVDR criterion. This constraint takes into account the uncertainty of the array manifold vector, such as array element position error, mutual coupling effect, etc. By solving the convex optimization problem, the robust beamforming weights that can still guarantee the expected signal gain in the worst case are obtained. Practice shows that this method can maintain good performance when the array element position error reaches 10% of the half wavelength.

[0190] To adapt to the dynamic changes of the signal environment, the recursive least squares (RLS) algorithm with adaptive step size is used to update the weight vector in real time. The adaptive step size mechanism can strike a balance between convergence speed and steady-state error. For example, in a scenario where the signal source moves quickly, a larger initial step size (such as 0.1) can quickly track the changes, and then gradually reduce the step size (such as to 0.01) to improve stability.

[0191] In order to improve the real-time performance of the algorithm, a fast subspace tracking algorithm based on the power iteration method is used. The algorithm updates the signal subspace and noise subspace efficiently through iteration, and the computational complexity is much lower than the full eigenvalue decomposition. In the real-time processing of the 16-element array, the algorithm can reduce the computation time of each update from milliseconds to microseconds, significantly improving the response speed of the system.

[0192] During the beamforming process, an adaptive notch filter is added to suppress narrowband interference. The center frequency and bandwidth of the notch filter are automatically determined by a peak detection algorithm based on discrete Fourier transform. For example, for a system with a bandwidth of 100MHz, the algorithm can detect and suppress narrowband interference with a bandwidth of less than 1MHz, and the suppression depth can reach more than 40dB.

[0193] To achieve accurate beam direction estimation, the multiple signal classification (MUSIC) algorithm and parabola interpolation technology are combined. The MUSIC algorithm provides a rough direction estimate, and then parabola interpolation is used to improve the angular resolution. Under the conditions of a 16-element array and a signal-to-noise ratio of 15dB, this method can achieve an angle estimation accuracy of 0.1°.

[0194] Based on the estimated signal direction, a fuzzy logic smoothing control strategy is used to dynamically adjust the main lobe direction of the beam. The fuzzy logic controller outputs the beam adjustment amount based on inputs such as the current direction estimate, estimated change rate, and signal strength. This strategy effectively avoids beam jitter caused by instantaneous estimation errors and improves the stability of the system.

[0195] Finally, the system calculates the signal-to-noise ratio and signal-to-interference ratio of the output signal in real time and feeds these indicators back to the control module. The control module dynamically adjusts the algorithm parameters based on these indicators, such as the diagonal loading factor of the MVDR algorithm and the forgetting factor of the RLS algorithm. For example, when strong interference is detected, the diagonal loading factor is increased to improve robustness; when the signal environment changes rapidly, the forgetting factor is reduced to speed up tracking.

[0196] Through this series of carefully designed steps, the digital beamforming algorithm can effectively optimize the phased array antenna system and realize adaptive adjustment of the beam and interference suppression. In practical applications, the algorithm achieves a processing delay of 1ms on a 16×16 array, meeting most real-time processing requirements. In the presence of multiple strong interference sources, the system can form an interference suppression zero with a depth of more than 40dB while maintaining the stability of the main lobe gain. In scenarios where the signal source moves rapidly, the algorithm can complete beam re-pointing within 50ms, meeting the requirements in highly dynamic environments. This high-performance, low-latency digital beamforming algorithm provides strong support for the application of phased array antenna systems in complex electromagnetic environments.

[0197] Figure 2 FIG. 1 is a schematic diagram of a structure of a phased array antenna design system based on microwave heterogeneous and heterogeneous integration according to an embodiment of the present invention. Figure 2 As shown, the system comprises:

[0198] The first unit is used to select an organic substrate with low dielectric loss as an antenna radiation unit substrate, and select an aluminum nitride ceramic substrate with a high dielectric constant as a radio frequency transceiver chip substrate; heterogeneously integrate the organic substrate and the aluminum nitride ceramic substrate through microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate; design and process multiple microstrip antenna units on the organic substrate layer of the heterogeneous heterogeneous integrated substrate, and integrate the radio frequency transceiver chip on the aluminum nitride ceramic substrate layer of the heterogeneous heterogeneous integrated substrate;

[0199] The second unit is used to design a phased array antenna unit based on the heterogeneous heterogeneous integrated substrate; the phased array antenna unit includes a radiating unit, a feeding network, a phase shifter and a power amplifier; wherein the radiating unit adopts a broadband microstrip antenna structure, which is realized by providing a multi-layer metallization pattern on the organic substrate; the feeding network adopts a microstrip line-slot line-microstrip line conversion structure, which is provided in a transition layer between the organic substrate and the aluminum nitride ceramic substrate to achieve vertical interconnection; the phase shifter and the power amplifier are integrated on the aluminum nitride ceramic substrate;

[0200] The third unit is used to design an array of multiple phased array antenna units according to a preset geometric arrangement to form a phased array antenna system; integrate a beam control unit in the phased array antenna system, and the beam control unit achieves precise control of the beam direction by adjusting the phase shifter of each phased array antenna unit; design and integrate a temperature compensation circuit, and the temperature compensation circuit dynamically adjusts the operating parameters of the phase shifter and the power amplifier by real-time monitoring the temperature change of the heterogeneous heterogeneous integrated substrate to ensure the stable performance of the phased array antenna system under different temperature environments; finally, optimize the phased array antenna system through a digital beamforming algorithm to achieve adaptive adjustment of the beam and interference suppression.

[0201] According to a third aspect of the embodiments of the present invention,

[0202] An electronic device is provided, comprising:

[0203] processor;

[0204] a memory for storing processor-executable instructions;

[0205] The processor is configured to call the instructions stored in the memory to execute the aforementioned method.

[0206] A fourth aspect of the embodiments of the present invention is:

[0207] A computer-readable storage medium is provided, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the aforementioned method is implemented.

[0208] The present invention may be a method, an apparatus, a system and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for executing various aspects of the present invention.

[0209] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A phased array antenna design method based on microwave heterogeneous integration, characterized in that: include: An organic substrate with low dielectric loss is selected as the antenna radiation unit substrate, and an aluminum nitride ceramic substrate with high dielectric constant is selected as the RF transceiver chip substrate; The organic substrate and the aluminum nitride ceramic substrate are heterogeneously integrated by microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate; a plurality of microstrip antenna units are designed and processed on the organic substrate layer of the heterogeneous heterogeneous integrated substrate, and a radio frequency transceiver chip is integrated on the aluminum nitride ceramic substrate layer of the heterogeneous heterogeneous integrated substrate; Based on the heterogeneous heterogeneous integrated substrate, a phased array antenna unit is designed; the phased array antenna unit includes a radiating unit, a feeding network, a phase shifter and a power amplifier; wherein the radiating unit adopts a broadband microstrip antenna structure, which is realized by arranging a multi-layer metallization pattern on the organic substrate; the feeding network adopts a microstrip line-slot line-microstrip line conversion structure, which is arranged in a transition layer between the organic substrate and the aluminum nitride ceramic substrate to realize vertical interconnection; the phase shifter and the power amplifier are integrated on the aluminum nitride ceramic substrate; The plurality of phased array antenna units are arrayed according to a preset geometric arrangement to form a phased array antenna system; a beam control unit is integrated in the phased array antenna system, and the beam control unit achieves precise control of the beam direction by adjusting the phase shifter of each phased array antenna unit; a temperature compensation circuit is designed and integrated, and the temperature compensation circuit dynamically adjusts the operating parameters of the phase shifter and the power amplifier by real-time monitoring the temperature change of the heterogeneous heterogeneous integrated substrate to ensure the stable performance of the phased array antenna system under different temperature environments; finally, the phased array antenna system is optimized by a digital beamforming algorithm to achieve adaptive adjustment of the beam and interference suppression.

2. The method according to claim 1, characterized in that The organic substrate and the aluminum nitride ceramic substrate are heterogeneously integrated by microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate, comprising: Substrate preparation: an organic substrate is selected as the antenna radiation unit substrate, and an aluminum nitride ceramic substrate is selected as the RF transceiver chip substrate; vertical interconnection vias are formed on the organic substrate and the aluminum nitride ceramic substrate respectively, and the diameter, depth and spacing of the vertical interconnection vias are optimized so that the insertion loss of the vertical interconnection vias in the 30GHz frequency band is controlled within 0.1dB and the return loss is better than -20dB; Electromagnetic shielding structure design: an electromagnetic shielding structure consisting of multiple layers of metal rings is designed around the vertical interconnection vias, and the crosstalk level is reduced to below -40 dB by controlling the size and spacing of the multiple layers of metal rings; Preparation of heat dissipation layer: preparing a carbon nanotube heat dissipation layer between the organic substrate and the aluminum nitride ceramic substrate, wherein the thermal conductivity of the carbon nanotube heat dissipation layer is greater than 2000 W / m·K and the thermal expansion coefficient is less than 1 ppm / K; Preparation of adhesive: preparing nano silver paste as adhesive, wherein the curing temperature of the nano silver paste is 150°C, and the thermal conductivity is 200 W / m·K. By optimizing the formula and curing process of the nano silver paste, the interface bonding strength reaches 80 MPa; Alignment and pressing: using infrared holographic interference technology to align the organic substrate and the aluminum nitride ceramic substrate with submicron precision, and then pressing them using a step-by-step pressurization and temperature gradient control strategy; Quality inspection: X-ray tomography and ultrasonic imaging technologies are used to inspect the heterogeneous and heterogeneous integrated substrates after lamination to confirm the interface quality and internal structural integrity.

3. The method according to claim 1, characterized in that Integrating a beam control unit in the phased array antenna system, wherein the beam control unit adjusts the phase shifter of each phased array antenna unit to achieve precise control of the beam direction includes: Initialize the beam control unit: use Xilinx Virtex UltraScale+ FPGA as the core processor, and the clock frequency of the FPGA is 1.5 GHz; High-precision phase control: A high-speed digital-to-analog converter with 16-bit resolution and 2.5 GSPS update rate is used. By designing a clock distribution network and jitter cleaning circuit, the effective number of digits of the high-speed digital-to-analog converter is increased to 14.5 bits, achieving a phase control accuracy of 0.022°. High-speed data transmission: Use the JESD204B high-speed serial interface to connect the FPGA and the high-speed digital-to-analog converter, optimize the link layer parameters of JESD204B, and control the interface delay within 100ns; Adaptive interference suppression: An interference suppression module based on space-time adaptive processing technology is integrated in the beam control unit, and an improved QR-RLS algorithm is used to suppress interference signals. The algorithm processing delay is controlled within 5μs through hardware acceleration and pipeline processing; Modular system integration: the beam control unit is divided into a digital processing module, a digital-to-analog conversion module and a radio frequency front-end module, and the modules are interconnected through a high-speed backplane; Self-check and calibration: Design a self-check and calibration system to monitor the working status of each module in real time and dynamically compensate system parameters according to temperature and aging factors; Beam control: The phase weight of each phased array antenna unit is calculated by the FPGA, and the phase control signal is sent to the phase shifter of each phased array antenna unit through the high-speed digital-to-analog converter.

4. The method according to claim 3, characterized in that Integrating an interference suppression module based on space-time adaptive processing technology in the beam control unit and adopting an improved QR-RLS algorithm to suppress interference signals includes: receiving an input signal of a phased array antenna system, converting the input signal into a frequency domain signal, and decomposing the frequency domain signal into a plurality of sub-band signals; Decompose the input covariance matrix into four sub-block matrices, two of which are square matrices and the other two are complementary non-square matrices; Performing QR decomposition on the two square matrix sub-block matrices respectively to obtain an orthogonal matrix and an upper triangular matrix; Converting the two non-square sub-block matrices into upper triangular matrices by orthogonal transformation; The matrix rotation is realized by using the QR decomposition method based on Givens rotation, where the rotation parameters are calculated by the ratio of the input elements; Calculate an adaptive forgetting factor, where the value of the forgetting factor is adjusted exponentially according to the square value of the estimation error; Update the filter weights based on the Givens rotation results and the adaptive forgetting factor; Perform adaptive filtering on each sub-band signal independently to obtain multiple sub-band filtering results; The multiple sub-band filtering results are synthesized into a complete output signal through a polyphase filter; Adopting data flow architecture, the functional modules of QR decomposition, back substitution solution and weight update are connected through high-speed first-in-first-out queues to form a pipeline structure; According to the characteristics of the input signal, the parallelism of each functional module is automatically adjusted to achieve dynamic allocation of computing resources.

5. The method according to claim 1, characterized in that Designing and integrating a temperature compensation circuit, wherein the temperature compensation circuit dynamically adjusts the operating parameters of the phase shifter and the power amplifier by real-time monitoring the temperature change of the heterogeneous heterogeneous integrated substrate to ensure the stable performance of the phased array antenna system under different temperature environments includes: The temperature of the heterogeneous heterogeneous integrated substrate is monitored in real time using a temperature sensor based on subthreshold CMOS, wherein the temperature sensor comprises a differential pair circuit composed of two MOS tubes of different sizes; Adopting dynamic component matching technology, 8 identical differential pair circuits are switched to the output end in turn through an 8:1 multiplexer to eliminate the nonlinear error caused by device mismatch. The output voltage of the temperature sensor is converted into a digital signal using a time-to-digital converter based on the Vernier delay line principle, wherein the time-to-digital converter comprises two delay lines with different delays and a multi-bit quantizer; The temperature compensation parameters are calculated based on a combination of a lookup table and interpolation method, where the lookup table is stored in an on-chip SRAM and contains the correspondence between temperature and key parameters of the phase shifter and the power amplifier; By injecting a known calibration signal, measuring the actual system output at different temperature points, and generating an individualized temperature-performance curve for the device, it is used to optimize the compensation parameters. A programmable current source circuit is used to adjust the bias current of the power amplifier, and a piecewise linear fitting method is used to describe the relationship between the bias current and temperature. The phase shift amount of the phase shifter is adjusted using the varactor-based phase shift compensation technique, and the bias voltage of the varactor is controlled by a 14-bit current-driven digital-to-analog converter; According to the calculated compensation parameters, the phase shift amount of the phase shifter and the bias current of the power amplifier are adjusted simultaneously to achieve real-time compensation for temperature changes.

6. The method according to claim 1, characterized in that The phased array antenna system is optimized by a digital beamforming algorithm to achieve adaptive beam adjustment and interference suppression including: The signal received by each array element is sampled using a high-speed analog-to-digital converter with a sampling rate of 100MHz and a resolution of 14 bits. The sampled data is converted to baseband through digital down-conversion and low-pass filtering; The covariance matrix of the signal is estimated using the sliding time window method, with a window length of 1024 sampling points and an overlap rate of 50%, and the forward and backward averaging technique is used to improve the estimation accuracy; Perform eigenvalue decomposition on the estimated covariance matrix, adaptively determine the number of retained eigenvalues ​​K by the minimum description length criterion, and reconstruct the covariance matrix using the K largest eigenvalues ​​and their corresponding eigenvectors; Based on the reconstructed covariance matrix, the linear equations are solved by using Cholesky decomposition and forward-backward substitution method to calculate the minimum variance distortion-free response beamforming weight vector. The ellipsoid uncertainty set constraint is introduced into the minimum variance distortion-free response criterion, the uncertainty of array manifold vector is considered, and the robust beamforming weights are obtained by solving the convex optimization problem. The weight vector is updated in real time using a recursive least squares algorithm with an adaptive step size to adapt to the dynamic changes in the signal environment; A fast subspace tracking algorithm based on power iteration method is used to efficiently update the signal subspace and noise subspace and quickly adjust the beamforming weights. An adaptive notch filter is added during the beamforming process, whose center frequency and bandwidth are automatically determined by a peak detection algorithm based on discrete Fourier transform to suppress narrowband interference; Combining the multi-signal classification algorithm and parabolic interpolation technology to estimate the beam direction, achieving an angle estimation accuracy of 0.1°; Based on the estimated signal direction, a fuzzy logic smoothing control strategy is used to dynamically adjust the main lobe direction of the beam to avoid beam jitter caused by instantaneous estimation errors. The signal-to-noise ratio and signal-to-interference ratio of the output signal are calculated in real time and fed back to the control module, which dynamically adjusts the algorithm parameters accordingly, including the diagonal loading factor of the minimum variance distortion-free response and the forgetting factor of the recursive least squares algorithm.

7. A phased array antenna design system based on microwave heterogeneous integration, used to implement the method according to any one of claims 1 to 6, characterized in that: include: The first unit is used to select an organic substrate with low dielectric loss as an antenna radiation unit substrate, and select an aluminum nitride ceramic substrate with a high dielectric constant as a radio frequency transceiver chip substrate; The organic substrate and the aluminum nitride ceramic substrate are heterogeneously integrated by microwave interconnection technology to form an integrated heterogeneous heterogeneous integrated substrate; a plurality of microstrip antenna units are designed and processed on the organic substrate layer of the heterogeneous heterogeneous integrated substrate, and a radio frequency transceiver chip is integrated on the aluminum nitride ceramic substrate layer of the heterogeneous heterogeneous integrated substrate; The second unit is used to design a phased array antenna unit based on the heterogeneous heterogeneous integrated substrate; the phased array antenna unit includes a radiating unit, a feeding network, a phase shifter and a power amplifier; wherein the radiating unit adopts a broadband microstrip antenna structure, which is realized by providing a multi-layer metallization pattern on the organic substrate; the feeding network adopts a microstrip line-slot line-microstrip line conversion structure, which is provided in a transition layer between the organic substrate and the aluminum nitride ceramic substrate to achieve vertical interconnection; the phase shifter and the power amplifier are integrated on the aluminum nitride ceramic substrate; The third unit is used to design an array of multiple phased array antenna units according to a preset geometric arrangement to form a phased array antenna system; integrate a beam control unit in the phased array antenna system, and the beam control unit achieves precise control of the beam direction by adjusting the phase shifter of each phased array antenna unit; design and integrate a temperature compensation circuit, and the temperature compensation circuit dynamically adjusts the operating parameters of the phase shifter and the power amplifier by real-time monitoring the temperature change of the heterogeneous heterogeneous integrated substrate to ensure the stable performance of the phased array antenna system under different temperature environments; finally, optimize the phased array antenna system through a digital beamforming algorithm to achieve adaptive adjustment of the beam and interference suppression.

8. An electronic device, characterized in that: include: processor; a memory for storing processor-executable instructions; The processor is configured to call the instructions stored in the memory to execute the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having computer program instructions stored thereon, characterized in that: When the computer program instructions are executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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