| 摘要 |
Plane waves are transmitted at different incident angles, and the radio frequency echo waveforms received by the elements in an array are processed with a Fourier transform. This method is capable of generating one frame of "raw" image for each transmitted plane wave. The formation of each raw image includes: temporal Fourier transform of radio frequency echo signal from each element; phase rotation; spatial Fourier transform; complex interpolation; and an inverse spatial-temporal Fourier transform. This method does not require the synthesis of limited diffraction beams and is computationally more efficient compared to conventional delay-and-sum approach. These raw images are combined coherently to enlarge spatial frequency coverage and enhance lateral resolution. The resolution-enhanced images are further combined incoherently to achieve speckle reduction.
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