5 results about "Nested arrays" patented technology

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.

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.

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.

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.