Active Metamaterial Based Ultrasonic Guided Wave Transducer System

An active and tunable metamaterial phased array transducer for guided wave mode selection with high intensity per driving channel and with dramatically lower modal noise when compared to the state of the art. The innovation exploits aspect of phased array based guided wave mode selection theory, whose practical significance seems to be ignored in the state of the art. These aspects include a) low modal noise when the phased array has small inter-element distance and a large number of elements and; b) phased delays necessary for driving the phased array elements have an apparent periodicity and anti-symmetry. As a consequence of exploiting the first factors the proposed phased array transducer can be classified as an active tuneable metamaterial. The second factor is mentioned above is exploited to reduce the number of driving channels by using switching matrices to interface between the driving channels and the metamaterial transducer. Fidelity of inspection and cost-effectiveness are the primary features of the innovation.