Calculation of Spatial Impulse Response for Array Transducer

Abstract

Unlike the conventional method of obtaining the spatial impulse response (SIR) for a transducer from the time domain, we propose a new and computationally efficient approach for calculating the acoustic field for a rectangular focusing array transducer in a transmitting, receiving, or transmitting–receiving (pulse–echo) mode from the frequency domain. The SIR spectrum, corresponding to each single frequency, is derived by superposing the sound fields generated by the subdivided rectangular sources. The time-domain pressure variation is obtained by taking the inverse Fourier transform from the combination of each SIR spectrum for the array. The results for a single rectangular transducer in transmitting and receiving modes match well with those from previous studies. The SIR spectrum for a focusing linear array transducer with multiple field scatterers is also developed. The proposed approach markedly reduces the number of sampling points, thereby substantially increasing the computation efficiency.