13 results about "Nested arrays" patented technology

The invention discloses a 4D millimeter wave radar antenna and a nested array and an anti-interference design method thereof. According to the method, a multi-transmitting and multi-receiving orthogonal array is adopted to construct a larger equivalent virtual aperture under a limited size, and hardware adopts a double-layer waveguide and is matched with multi-resonance broadband matching to cover 76-81 GHz; a multifunctional nested sub-array is introduced to realize division cooperation of long-distance narrow beam, short-distance high resolution and pitching enhancement, and a side lobe is suppressed and the size of an array plane is reduced by sharing aperture and channel multiplexing; the frequency spectrum orthogonality and mutual interference resistance of the same-domain radar are improved through segmented calibration, online interference detection and sub-band selection and switching; on the premise of meeting the resolution, the size of the module is reduced through sparse topological optimization. According to the method, the stable detection distance and the weak and small target detection capability can be improved, the fusion and false association probability is reduced, unnecessary braking is reduced, missing detection / false alarm caused by mutual interference is reduced, and the constraint on the whole vehicle model and the installation window is reduced.

This invention discloses a monostatic symmetric nested array MIMO system and a near-field positioning method, belonging to the field of monostatic MIMO near-field positioning technology. This invention can effectively improve the positioning performance during near-field estimation. The monostatic symmetric nested array MIMO system proposed in this invention has a symmetrically distributed transmit and receive arrays. Compared to other symmetric MIMO systems, its differential array is a positionally continuous array with more degrees of freedom. With the same physical array aperture, fewer physical array elements are actually used, reducing costs. The near-field positioning method proposed in this invention calculates the fourth-order statistics of the signal and quantizes them to obtain a virtual differential array of the differential array, achieving accurate near-field positioning of sparse MIMO structure arrays. Furthermore, it can be extended to more sparse MIMO symmetric systems.

The invention discloses a logical operation method based on depth-first traversal and stack recursion, and belongs to the technical field of computer logical operation and data processing. The method aims at solving the problems that in the prior art, when a complex nested logic expression is processed, operator priority judgment is complex, short circuit evaluation is difficult to achieve, and code maintainability is poor. The core of the method is that firstly, a nested logic expression to be calculated is abstracted into a tree-shaped or nested array data structure; secondly, a depth-first traversal algorithm is adopted to conduct recursive scanning on the data structure, and in the traversal process, encountered logic operators and basic judgment conditions (calculation factors) or intermediate calculation results of sub-expressions are sequentially pressed into a main stack according to the traversal sequence; when traversal of one sub-expression is completed, an actuator module is automatically triggered; and the executor module pops up a logic operator of the current action range from the main stack.

This invention belongs to the field of sound source localization technology and discloses a near-field sound source localization method based on a symmetrical nested array and weighted fourth-order cumulants. The invention uses a centrally symmetrical nested array as the signal receiving structure. By constructing a weighted fourth-order cumulant matrix, it improves the stability of statistical quantities while suppressing Gaussian noise, and establishes an equivalent high-order statistical model based on the array geometry. In the parameter estimation stage, a two-stage one-dimensional estimation strategy decoupling angle and distance is adopted: first, one-dimensional subspace estimation of angle is performed based on the weighted fourth-order cumulant matrix; then, one-dimensional search estimation of distance is performed under angle constraints, thereby avoiding the traditional two-dimensional spectral peak search process in the near field. Without increasing the array hardware complexity, this invention improves localization accuracy and stability through high-order statistical optimization and parameter estimation process improvement, while significantly reducing computational complexity, and has good engineering application value.

The application discloses a 4D millimeter wave radar antenna and a nested array and anti-interference design method thereof. The method adopts a multi-transmitting and multi-receiving orthogonal array to construct a larger equivalent virtual aperture under a limited size, a double-layer waveguide is adopted for hardware, and a multi-resonance broadband matching is matched to cover 76-81 GHz; a multifunctional nested subarray is introduced to realize the division and cooperation of long-distance narrow beam, short-distance high resolution and pitch enhancement, and to suppress the sidelobe and reduce the array size through shared aperture and channel multiplexing; the spectral orthogonality and anti-interference ability with the same domain radar are improved through segmented calibration, online interference detection, subband selection and switching; under the premise of meeting the resolution, the module size is reduced through sparse topology optimization. The application can improve the stable detection distance and weak target detection ability, reduce the fusion and misassociation probability, reduce unnecessary braking, reduce the missed detection / false alarm caused by mutual interference, and reduce the constraint on the vehicle modeling and installation window.

This invention discloses a high-degree-of-freedom, low-coupling sparse array design method based on fourth-order cumulants, comprising: A: constructing a non-Gaussian signal receiving model and constructing a fourth-order differential array of the non-Gaussian signal using fourth-order cumulants; B: constructing a coprime displacement array composed of two coprime displacement subarrays and determining the array parameters; C: constructing an expanded nested array composed of two nested subarrays and determining the array parameters; D: constructing an expanded nested coprime displacement array based on the coprime displacement array and the expanded nested array and determining the expansion factor, ultimately obtaining a high-degree-of-freedom, low-coupling sparse array based on fourth-order cumulants. This invention can achieve stronger anti-coupling capability while maintaining a degree of freedom comparable to existing sparse arrays, and can significantly improve the signal estimation accuracy and direction-of-arrival resolution.

A Ku-band self-biased circulator belongs to the field of microwave ferrite device technology. The circulator includes a composite substrate and a microstrip circuit formed on the composite substrate; wherein the composite substrate includes a secondary dielectric sheet and an array of ferrite rods nested within the secondary dielectric sheet, the array of ferrite rods being composed of nested array of ferrite rods and a primary dielectric substrate. This invention, by employing a composite substrate structure with array of ferrite rods nested within a primary dielectric substrate, effectively reduces the influence of demagnetizing fields through the placement of the rod-shaped ferrites. The synergistic generation of multiple rod-shaped ferrites produces a stable bias magnetic field, providing good control over the device's operating frequency range. While maintaining non-reciprocal characteristics, it significantly reduces magnetic loss in the Ku-band, thereby reducing insertion loss.

The application discloses a kind of absolute polynomial correlation entropy DOA estimation methods under pulse noise environment, receive signal by nested array structure antenna, according to received signal and absolute polynomial correlation entropy operator APCO calculate corresponding covariance matrix;With vectorization, ordering and redundancy are removed, obtain new virtual uniform linear array received signal;The continuous part of half wavelength between difference virtual array elements is spatially smoothed, and the spatially smoothed covariance matrix is constructed, and then the precise estimation of DOA is obtained by using the MUSIC method.The method uses absolute polynomial correlation entropy operator APCO to suppress pulse noise outliers, constructs APCO matrix, not only without relying on prior knowledge of noise, but also can get rid of the limitation of traditional correlation entropy algorithm, and can realize high-precision DOA estimation in strong pulse noise, low SNR, limited number of snapshots environment.

The invention discloses a low-frequency radiation unit, and relates to the technical field of antenna radiation units, the low-frequency radiation unit comprises a radiator, the radiator comprises a plurality of radiation arm units and a plurality of balun structures respectively corresponding to the plurality of radiation arm units, each radiation arm unit comprises a first radiation arm and a second radiation arm, the balun structure comprises a first balun wire correspondingly connected with the first radiation arm and a second balun wire correspondingly connected with the second radiation arm, and the first radiation arm, the second radiation arm, the first balun wire and the second balun wire are all provided with choking coil structures. The choking coil structure comprises a first branch knot and at least one second branch knot perpendicular to the first branch knot, and the choking coil structure is used for blocking high-frequency current coupled to the low-frequency radiation unit. The invention aims to enable the high-frequency radiation unit of the nested array antenna to obtain a good broadband radiation characteristic under the condition that the high-frequency radiation unit does not need to be lifted.

This invention relates to the technical field of adaptive array signal processing, and particularly to a direction-of-arrival (DOA) estimation method based on an improved SAMP (Single Amplifier Array) using nested arrays. This method addresses the technical problems in the prior art. It involves incident a far-field narrowband signal onto an extended nested array. Based on the signal's position information, the array manifold matrix is ​​obtained, leading to the array received data matrix of the nested interpolated uniform array. Then, based on the characteristics of the compressed sensing matrix, the array manifold is extended to obtain a DOA estimation mathematical model. This model is input into an improved adaptive matched-tracking algorithm to reconstruct the original input signal. Finally, the MUSIC algorithm is used for spectral peak search. This method can accurately achieve DOA estimation under conditions of small snapshots, low signal-to-noise ratio, and source coherence; it has low computational complexity; it can accurately recover the source with relatively few samples; and it effectively improves the DOA estimation accuracy and spatial resolution of nested arrays.

The invention discloses an absolute polynomial correlation entropy DOA estimation method in an impulse noise environment, and the method comprises the steps: receiving a signal through a nested array structure antenna, and calculating a corresponding covariance matrix according to the received signal and an absolute polynomial correlation entropy operator APCO; vectorization, sorting and redundancy elimination are carried out to obtain a new virtual uniform linear array receiving signal; and spatial smoothing processing is carried out on a continuous part of which the array element spacing of the difference virtual array is half wavelength, a spatial smoothing covariance matrix is constructed, and accurate estimation of the DOA is obtained by using a MUSIC method. According to the method, the absolute polynomial correlation entropy operator APCO is used for inhibiting the pulse noise abnormal value, the APCO matrix is constructed, dependence on priori knowledge of noise is not needed, limitation of a traditional correlation entropy algorithm can be eliminated, and high-precision DOA estimation can be achieved in the environment of strong pulse noise, low signal-to-noise ratio and limited snapshot number.

The application discloses a MongoDB nested array document migration synchronization method and system based on DataX, belongs to the technical field of databases and data migration, and will convert a nested array document Document object list read according to configuration into different types of data according to different requirement configuration parameters exportType; if the custom parameter exportType is empty, the original Document document format of the migrated data is reserved; if the custom parameter exportType is json, the migrated data is in a json array format; if the custom parameter exportType is csv, the migrated data is in a csv format; if the custom parameter exportType is expand, the nested array document of the migrated data is separated into independent records and output; different data formats are distinguished through parameters, different apis are called, and different business requirements are met. The application is suitable for the synchronization of the nested array document in the MongoDB to a new database system.

The application relates to a universal nested array configuration family antenna and a design method thereof, and comprises the following steps: determining the number of array elements and the element spacing of a three-level sparse subarray; designing a universal nested array configuration family and deducing the element position distribution; analyzing the internal geometric characteristics of each subarray in each array configuration in the family from a two-dimensional perspective; deducing the analytical expression of the continuous degrees of freedom of each array configuration in the nested array configuration family under the differential common array domain, and analyzing the influence of the value of a sequence factor in the array configuration family on the degrees of freedom. The application introduces the concept of "family" into the design of a sparse array, and proposes a design method of the nested array configuration family antenna. Different from a certain fixed array configuration, each array in the family can be transformed into each other, and the flexibility of the array layout is significantly increased.