Design of unidirectional acoustic probes with flexible directivity patterns using two acoustic particle velocity sensors

This letter proposes a method of designing unidirectional acoustic probes with flexible directivity patterns using two acoustic particle velocity sensors. The closed-form weighting vector of this two-sensor array is accurately derived by finding the minimum mean square error approximation to a desired directivity pattern that is expressed in a general form. Different unidirectional acoustic probes can be obtained by properly selecting the desired directivity pattern, and the previously proposed particle velocity gradient-based design approach can be thought of as a special case of the proposed method. Simulations and experimental results demonstrate the good performance of the proposed method.