A method to design an optimum pair of transmit and receive periodic sparse arrays

Abstract

In such applications as fast 3D imaging with 2D arrays and point-of-care imaging with an ultra portable devices, periodic sparse arrays(PSA) can be efficiently used to increase the effective aperture size with less number of active elements than the conventional method. Generally, PSA can be represented as sub-arrays distributed uniformly in P -element intervals, each with L consecutive elements, where L P < . Since the continuous wave beam pattern in the far-field is given by Fourier transform of aperture function, the beam pattern of PSA is a multiplication of beam patterns of the upsampled dense array by the ratio of P and L -elements sub-array. A recent method to design a PSA pair provides analytically the values of P and L for transmit and receive arrays to eliminate the dominant grating lobes, which occur at the same position on both transmit and receive. In this work, we present a method to design a PSA pair with improved performance by further suppressing the residual grating lobes of PSA. It can be accomplished by properly shading amplitude of the transmit and receive sparse arrays. This shading window function is also obtained by signal analysis of aperture functions. The beam patterns of various PSA pairs based on the proposed design method are evaluated through computer simulations. The simulation results show that the residual grating lobes are reduced by about 10dB more in all cases. Consequently, our method can be used to improve the performance of beam pattern or enhance the periodicity of sparse array.

An Analytical Approach to Designing Optimal Sparse 1-D Phased Arrays for Handheld Ultrasound Imaging

“…In the proposed design method, the transmit and receive PSA patterns are selected such that they do not have grating lobes at the same locations, called common grating lobes (CGLs), and the other grating lobes should be suppressed below a desired level after the beam patterns of the transmit PSA and the receive PSA are multiplied. This strategy was previously suggested by Kim and Song [20], [21] for the development of a portable ultrasound scanner for the POC application. In our previous works, however, there still existed a limitation on SF values that can be achieved, and the optimum beam pattern for a given SF could not be obtained.…”