Analysis of a tapered phase array transducer for 3D imaging applications

The tapered phased array (TPA) transducer consists of a linear array of piezoelectric elements which possess a linearly tapered thickness. In the transmit mode, the region of excitation along the elevation dimension of a tapered element is centered around that section having a resonance thickness that corresponds to the center frequency of the applied pulse. Reciprocally, in the receive mode, the frequency spectrum of the detached echoes can be used to obtain information from the elevation dimension of the object being imaged. An analysis of an experimental verification and its implications is presented. It is concluded that a 3D real-time imaging system is possible using the TPA. The frame rate will depend on the scanning speed as well as the computational power of the postprocessors. The scanning process is comparable to that currently used in real-time B-scan imaging systems, although the computational power required is several orders higher. Fortunately, the process can be easily distributed into parallel processing