US 10,624,612 B2 · Beamforming method, measurement and imaging instruments, and communication instruments

Abstract

Beamforming method that allows a high speed and high accuracy beamforming with no approximate interpolations. This beamforming method includes step (a) that generates reception signals by receiving waves arrival from a measurement object; and step (b) that performs a beamforming with respect to the reception signals generated by step (a); and step (b) including without performing wavenumber matching including approximate interpolation processings with respect to the reception signals, and the reception signals are Fourier's transformed in the axial direction and the calculated Fourier's transform is multiplied to a complex exponential function expressed using a wavenumber of the wave and a carrier frequency to perform wavenumber matching in the lateral direction and further, the product is Fourier's transformed in the lateral direction and the calculated result is multiplied to a complex exponential function, from which an effect of the lateral wavenumber matching is removed, to perform wavenumber matching in the axial direction, by which an image signal is generated.

Claims40

Dependent claims

A beamforming method which is used in a measurement and imaging instrument for generating an image signal with respect to a measurement object when a wave source positioned at an arbitrary direction transmits an arbitrary wave toward said measurement object in an orthogonal coordinate system determined by a reception aperture element array, said beamforming method comprising the steps of:

(a) receiving a wave arrived from said measurement object by using at least one reception aperture element to generate a reception signal;
and
(b) performing a transmission and/or reception beamforming processing at least by implementing wavenumber matching with Fourier's transform onto said reception signal generated at step (a),
wherein step (b) includes performing a transmission and/or reception steering with a steering angle direction expressed at least by a zero or non-zero angle of a deflection, an elevation, or an azimuth with respect to a frontal direction of said at least one reception aperture element, and directly generating the image signal in a desirable orthogonal coordinate system based on said wavenumber matching by multiplying complex exponential functions, which are expressed using at least said steering angle direction, onto said reception signal in respective directions of orthogonal spatial coordinate axes with performing Fourier's transform onto said reception signal with respect to said orthogonal spatial coordinate axes so as to match wavenumber coordinates of angular spectra of said reception signal to wavenumber coordinates of spectra corresponding to said image signal without directly implementing interpolation approximations onto said angular spectra.

1 more element

A measurement and imaging instrument for generating an image signal with respect to a measurement object when a wave source positioned at an arbitrary direction transmits an arbitrary wave toward said measurement object in an orthogonal coordinate system determined by a reception aperture element array, said measurement and imaging instrument comprising:

at least one reception aperture element configured to receive a wave arrived from said measurement object to generate a reception signal;
and
a digital signal processing unit configured to perform a transmission and/or reception beamforming processing at least by implementing wavenumber matching with Fourier's, transform onto said reception signal generated by said reception aperture element,
wherein said digital signal processing unit performs a transmission and/or reception steering with a steering angle direction expressed at least by a zero or non-zero angle of a deflection, an elevation, or an azimuth with respect to a frontal direction of said at least one reception aperture element, and directly generates the image signal in a desirable orthogonal coordinate system based on said wavenumber matching by multiplying complex exponential functions, which are expressed using at least said steering angle direction, onto said reception signal in respective directions of orthogonal spatial coordinate axes with performing Fourier's transform onto said reception signal with respect to said orthogonal spatial coordinate axes so as to match wavenumber coordinates of angular spectra of said reception signal to wavenumber coordinates of spectra corresponding to said image signal without directly implementing interpolation approximations onto said angular spectra.

1 more element

Dependencies are inferred from the claim text.

Beamforming method, measurement and imaging instruments, and communication instruments

Life of this patent

Beamforming method, measurement and imaging instruments, and communication instruments

Life of this patent

Abstract

Claims40