140 results about "Thinned array" patented technology

Provided herein is a method for use in medical applications that permits (1) affordable three-dimensional imaging of blood flow using a low-profile easily-attached transducer pad, (2) real-time blood-flow vector velocity, and (3) long-term unattended Doppler-ultrasound monitoring in spite of motion of the patient or pad. The pad and associated processor collects and Doppler processes ultrasound blood velocity data in a three dimensional region through the use of a planar phased array of piezoelectric elements. The invention locks onto and tracks the points in three-dimensional space that produce the locally maximum blood velocity signals. The integrated coordinates of points acquired by the accurate tracking process is used to form a three-dimensional map of blood vessels and provide a display that can be used to select multiple points of interest for expanded data collection and for long term continuous and unattended blood flow monitoring. The three dimensional map allows for the calculation of vector velocity from measured radial Doppler.

A thinned array (greater than half-wavelength element spacing of the transducer array) is used to make a device of the present invention inexpensive and allow the pad to have a low profile (fewer connecting cables for a given spatial resolution). The full aperture is used for transmit and receive so that there is no loss of sensitivity (signal-to-noise ratio) or dynamic range. Utilizing more elements (extending the physical array) without increasing the number of active elements increases the angular field of view. A further increase is obtained by utilizing a convex non-planar surface.

A prior application discloses a novel probe geometry that offers a wide field of view in an ultrasonic imaging device. That geometry is referred to as a "thinned array" of transducer elements. The application discloses an improved probe geometry permitting high-resolution imaging of a large volume of the subject's body. In this improved geometry, the array elements are non-uniform in size and spacing. The probe is intended for use, for example, in a method of determining parameters of blood flow, such as vector velocity, blood flow volume, and Doppler spectral distribution, using sonic energy (ultrasound) and a novel thinned array. Also in a method of tracking blood flow and generating a three dimensional image of blood vessel of interest that has much greater resolution than images produced using heretofore known ultrasound devices and methods.

The invention discloses a microwave related imaging system and a microwave related imaging method based on a thinned array, which mainly aim to solve the problems of poor imaging effect and low resolution when non-radial relative movement does not exist between a radar antenna and a target in the prior art. The system comprises a transmitting antenna (1), a target (2), a receiver (3) and a signal processor (5), wherein the transmitting antenna (1) is formed by a thinned array antenna; different microwave coded signals are transmitted by all array elements, so as to form a microwave radiation field in space through incoherent superposition; the target (2) is irradiated through the microwave radiation field, so as to generate target scattering echoes; the microwave radiation field (4) on the surface of the target (2) is stored; the target scattering echoes are received by the receiver (3) through a single antenna and a single channel; and the target scattering echoes received by the receiver (3) and the pre-stored microwave radiation field (4) are processed by the signal processor (5), so as to obtain the imaging of the target. By using the system and the method, super-resolution imaging of the target without ambiguity can be realized when the non-radial relative movement does not exist between the radar antenna and the target, and the system and the method can be used for super-resolution imaging of the target by an airborne forward-looking radar and a ball-borne radar.

The invention discloses a thinned array near-field passive location amplitude and phase error correction method, and relates to the technical field of phased array radar. The method comprises the following steps: under the condition that a target is located in a near field, fixing the pitch angle Phi, alternately and cyclically estimating the distance and azimuth angle of the target until the two parameters converge to the real values, and taking the position as the initial position of error correction; then, carrying out one-dimensional search of the azimuth angle of the target, correcting the array amplitude and phase error using an amplitude and phase error self-correction method, and estimating an array amplitude and phase error matrix gamma(theta) and the first iteration value theta' of the azimuth angle; estimating an array amplitude and phase error matrix gamma(r) and the first iteration value of the distance of the target; and carrying out loop iteration until ||gamma(theta)-gamma(r)||<epsilon2, namely, the estimated values of the parameters converge to the real values. Array element positions are arranged randomly and sparsely within a certain arraying range, the same angle resolution can be achieved with only a small number of array elements, and the cost can be reduced in practical engineering.

A process for fabricating an integrated circuit package. Metal is plated up on a substrate to provide a plurality of contacts pads and a plurality of fiducial markings on a periphery of the contacts. A transparent mask is selectively deposited on the substrate, over the fiducial markings. A semiconductor die is mounted on the substrate such that the contact pads circumscribe the semiconductor die and the semiconductor die is wire bonded to ones of the contact pads. The wire bonds are encapsulated and the semiconductor die and contact pads are covered in a molding material. The substrate is selectively etched to thereby etch away the substrate underneath the contact pads and the semiconductor die. The integrated circuit package is singulated from other integrated circuit packages by sawing using the fiducial markings.

A conformal retro-modulator optical apparatus. The apparatus includes an array of multiple quantum well devices disposed in a thin array. A plastic support element is bonded to the thin array, the plastic support element having a thickness greater that of the thin array. The plastic support element is preferably plastic at elevated temperatures above room temperature, thereby allowing the plastic support element and the thin array of multiple well device disposed therein to conform to a predetermined shape, yet being rigid at room temperature.

The invention relates to a near-field delay calibration method for channels of a broadband thinned array radar, which comprises the following steps of: erecting a signal source in the near-field environment to radiate frequency-modulated signals with a certain frequencies and broadbands, receiving the signals radiated by the signal source by using a large-scale thinned array antenna to be calibrated and acquiring the signals received by each channel; converting the channel signals into a frequency domain by using a dechirping technology; acquiring a high-precision estimation of a frequency difference value of the channel signals in the frequency domain by using a frequency difference value high-precision estimation method so as to obtain a delay estimation initial value of the channel signals; correcting a phase difference value of the channels by using a time domain delay high-precision estimation method to obtain a delay calibration value of the channels; and calibrating a delay filter of a signal processing unit of the thinned array radar by the calibration value.

The discloses a synthesis method of a broadband frequency independent thinned array taking mutual coupling effect into account, and relates to array antennae. Iterative weighted first norm is adopted in a plurality of limiting conditions, and the limiting conditions comprise a spatial response change limit, a side lobe level upper boundary limit and an expected direction limit. As the limiting conditions are all convex problems, the problems are optimized through iterative second-order cone programming. In a target working frequency range, low side lobe level can be kept, the quantity of array elements can be effectively reduced under a main lobe frequency independent performance, the hardware complexity and the engineering cost are furthest reduced. In addition, electromagnetic mutual coupling effect met in the practical application is considered, and error, caused by coupling, of an antenna system is effectively avoided.

The invention provides a sparse array optimization method based on an adaptive genetic algorithm in the technical field of radar reconnaissance array optimization. The method comprises the following steps of optimizing a model by proposing an array, encoding arrays, then, calculating a fitness value by utilizing a Cramer-Rao bound; selecting and crossly mutating the generated individuals by utilizing the fitness value, correspondingly changing crossover probability and mutation probability along with the increase of iteration times, finally optimizing to obtain the optimal individual, and taking the sparse array placement mode corresponding to the optimal individual as the optimal placement mode of array elements in the radar array. The method is a sparse array optimization method based ona self-adaptive genetic algorithm, an array element selection mode mainly takes the maximum array aperture and the minimum array element spacing as constraint conditions, takes a Cramer-Rao bound asa fitness function, and ensures that the array has relatively high direction finding performance under the conditions of the same array element number and the same minimum array element spacing.

The invention discloses an MIMO radar sparse array optimization method based on an MODE algorithm, and relates to the technical field of radar imaging systems. The method comprises two steps to complete sparse array optimization. On the basis of completing the establishment of a covariance matrix, problem modeling is carried out mainly for sparse array optimization. According to the method, a CA+CA+DE algorithm is used for solving a single-objective optimization problem, then single-objective optimization is used as a constraint condition of the optimization, then the single-objective optimization problem is converted into a multi-objective optimization problem, and finally a multi-objective MODE optimization algorithm is used for solving to obtain a sparse array which meets directional diagram matching and inhibits side lobes. The method can converge to global optimization under the condition that the directional diagram is fixed, and the convergence speed is high.

The invention discloses an automobile millimeter wave radar sparse array grating lobe false target identification method and system, belongs to the technical field of automobile radar, and is used forsolving the problem of grating lobe false targets caused by the fact that an existing automobile radar adopts a sparse array. The method comprises the following steps: 1) target detection, (2) targetangle estimation, (3) target echo power sorting and normalization in different directions, (4) false interference covariance matrix construction, (5) self-adaptive weight calculation, (6) spatial spectrum recalculation based on the self-adaptive weight, and (7) false target identification after wave beam output normalization. The method and system have the advantages of grating lobe false targetavoidance, angle resolution improvement and the like.

The invention relates to a target orientation and distance combined sparse reconstruction positioning method based on a seabed horizontal L-shaped array. The method comprises the following steps: laying a horizontal L-shaped array at the seabed, receiving sound signals emitted by multiple targets near the sea surface, and obtaining a source matrix of the multiple targets; in the azimuth and distance two-dimensional plane of the target, obtaining a sparse source matrix about the target; obtaining a sparse array matrix about N-element L-shaped array receiving signals; reconstructing a sparse signal by using the obtained sparse array matrix and the normalized sparse source matrix; adopting a norm regularization method to carry out optimal solution on the reconstructed sparse signals; and determining the orientation and distance information of the target according to the spectral peak position and intensity of the spatial spectrum, and judging the relative size of the target power. According to the method, the influence of multipath interference on the target azimuth-distance joint estimation precision can be effectively stripped and reduced, the target positioning result without spatial ambiguity is obtained, and the position information and the relative intensity of multiple targets can be accurately obtained at the same time.

The invention discloses a design method of an optimal motion linear sparse array under an underdetermined signal source, and solves the problem of obtaining a motion sparse array with the minimum CRB(Cramer-Rao bound) under the underdetermined signal source, wherein the motion sparse array meets the requirements of aperture and array element number. The method comprises the following implementation steps: obtaining a differential array Dc of a motion linear sparse array and an array flow pattern matrix Ac of the differential array Dc; calculating CRB of the motion linear sparse array with respect to direction of arrival estimation; and optimizing the linear sparse array by using an improved genetic algorithm to obtain an optimal array structure Sopt. The invention provides a Cramer-Rao bound expression of a motion linear sparse array relative to direction-of-arrival estimation under an underdetermined signal source. A fancy competition selection method is introduced, and a preferred strategy is adopted in the crossover mutation process so that local convergence is avoided. The CRB of the obtained optimal array relative to direction-of-arrival estimation is smaller, and DOA estimation performance is improved. The optimal array structure can be easily adjusted when the signal environment changes. The method is used for high-precision DOA estimation.