An efficient digital beamsteering system for difference frequency in parametric array

For a digital beamsteering system, the smallest time delay available is equal to the sampling period of the digital signal processing (DSP) board. As most of the time the sampling frequency is not high enough, the smallest steering angle available is large, which is undesirable. This limitation also occurs when performing beamsteering in a parametric array [2] digitally. Although partial delay or frequency domain algorithms can be used to improve the steering angle, most of the algorithms are either computational intensive or introduce error during the process. In this paper, an algorithm is proposed to beamsteer the difference frequency in parametric array. The proposed system can be used to steer the difference frequency to a small angle, without the need to increase the sampling frequency or implement partial delay.