7 results about "Pattern synthesis" patented technology

The application provides a movable antenna array pattern synthesis method based on an improved fish eagle optimization algorithm, converts antenna positions and antenna weights into a joint variable vector, improves an update strategy on the basis of an original fish eagle optimization algorithm, introduces global search exploration based on levy flight in a first stage, and adds an adaptive probability mechanism to dynamically guide a search scheme for selecting between a global optimal value and a same-generation optimal value to strengthen exploration diversity, adopts Gaussian disturbance in a second stage to perform local fine exploration and dynamically attenuate an update step to further optimize a solution in the first stage, prevent premature convergence, and be applied to a pattern synthesis problem in a movable antenna array, consider engineering practical constraints such as a minimum spacing between antenna arrays and a maximum aperture range, and can effectively realize target enhancement, interference suppression and various practical application scenarios such as a shaped beam.

This invention provides a beamformer-based feed design method. By utilizing a pattern synthesis method based on Fourier transform, the excitation amplitude and phase of each array element are obtained through inverse synthesis. The obtained excitation amplitude and phase of each array element are then assigned to that element. Full-wave simulation of the array is performed in electromagnetic simulation software to obtain the array's radiation pattern, which is compared with the desired feed radiation pattern. If deviations exist, the excitation amplitude and phase can be adjusted until the overlap with the desired feed radiation pattern reaches the target. This invention achieves nearly 90% efficiency after illuminating the reflector, far exceeding the efficiency of conventional feeds illuminating reflectors. Furthermore, different excitation coefficients can be flexibly constructed for different frequencies, achieving high-precision approximation of the ideal delta function across a wide frequency range. Higher gain can be obtained with the same aperture, or the aperture size of the reflector antenna can be reduced with the same gain requirements. This significantly improves system performance and reliability.

This invention proposes a method and apparatus for synthesizing array radar radiation patterns using space-time joint modulation. The method includes: determining initial values ​​of the array radar element excitation coefficients; acquiring the array far-field radiation pattern under the influence of the initial values ​​of the element excitation coefficients; dividing the array far-field radiation pattern into main lobe and side lobe regions based on its characteristics; setting the random modulation phase of the main lobe region to zero, maintaining the same main lobe phase across different pulses, while modulating the phase of the side lobe region regularly or randomly, while keeping the array far-field radiation pattern amplitude constant, thus obtaining array radiation patterns with different phase characteristics under multiple pulses; performing Fourier transforms on the array radiation patterns under different pulses to obtain the space-time two-dimensional element excitation coefficients; and applying the space-time two-dimensional element excitation coefficients to the array radar system to synthesize the array radar radiation pattern after space-time joint modulation. This invention significantly improves the array radar's resistance to sidelobe clutter and interference.

This invention discloses a pattern synthesis method for constrained metasurface generation driven by near-field and far-field matching factors, belonging to the field of wireless communication and microwave antenna technology. This invention transforms the metasurface beam synthesis problem into a cross-correlation matching problem between a near-field equivalent source and a far-field target. It constructs a core design framework for constrained metasurface generation driven by matching factors calculated from the target pattern and the near field. Utilizing the electromagnetic reciprocity principle, it transforms the complex non-convex inverse design problem into a physically clear power matching problem. By quantifying the field-source matching degree of the local near field to the target far field and allocating amplitude coupling resources, it pre-constrains physical and manufacturing processes. Under the condition of only limited amplitude adjustment degrees of freedom, it efficiently and accurately generates physically realizable metasurface structures. This invention effectively solves the problems of post-mapping distortion in holographic methods and poor convergence of optimization algorithms, significantly shortens the R&D cycle of metasurface antennas, and lowers the implementation threshold, possessing significant meaning and value.

This invention discloses a fast method for generating broadband null patterns, belonging to the field of array signal processing. First, the invention constructs an objective function and its constraints based on the pointing of the main lobe and nulls of the pattern. After converting this function into a Lagrangian function, its extreme points are solved to obtain the analytical expression of the array excitation vector at each sampling frequency. Next, the FIR filter coefficients are solved based on the element excitations corresponding to each frequency sampling point. Finally, a filter is constructed based on the FIR filter coefficients to obtain the desired broadband array pattern synthesis result. This invention provides a fully analytical expression for generating null pattern element excitations, solving the problem of large computational load and long processing time caused by multiple iterations of optimization algorithms in existing methods. It possesses real-time synthesis capabilities and has engineering application significance.

The application provides a binary snake optimization algorithm-based antenna sparse array design method, and belongs to the field of antenna array pattern synthesis. The application is based on a snake optimization algorithm, a probability estimation model is added in the algorithm, a new binary coding snake optimization algorithm is provided, and the new binary coding snake optimization algorithm is applied to a sparse planar array layout optimization problem. The new probability estimation model can better map the slight change caused by the update function in the algorithm to the binary coding, maintain the diversity of the population, enhance the global search ability, and also reserve the exploration and development ability of the original algorithm. The method has the global search ability and fast convergence, and improves the sidelobe suppression ability of the sparse antenna.

(Independent system) System for generating playable structured practice files for a string instrument, including: - a processor and a memory connected to the processor containing instructions; - an input module (101) configured to receive user input and to transform the input into a set of quantifiable parameters, including at least tempo, rhythmic subdivision, technique type and difficulty level; - a pattern database (102) containing abstracted musical patterns, each indexed with metadata that includes tonal, rhythmic, technical and physical playability attributes; - a retrieval module (103) configured to retrieve patterns from the pattern database based on parameters derived from the input module; - a synthesis module (104) configured to combine and transform retrieved patterns into at least one candidate sequence; characterized in that the system further comprises: - a constraint module (105) configured to derive dynamic physical playability constraints as a function of the quantifiable parameters, wherein the constraints represent physical properties of the target instrument and biomechanical limits of the performer and include at least: (a) a string-specific maximum fret position, derived from the physical construction of the instrument, (b) a maximum grip span as a function of the difficulty level, derived from the biomechanical reach of the human hand, (c) a maximum positional shift along the fingerboard per time interval as a function of tempo and technique type; - a validation module (106) configured to check each candidate sequence against all constraints derived from the Constraint module and to reject or modify sequences that violate at least one constraint; - an output module (107) configured to encode validated sequences into an instrument-specific binary notation format that includes at least string assignment, fret position, time value and technique annotation for each note.