Single-transducer ultrasonic continuous-wave system for transmitting coded sequences

A major challenge in CW ultrasonic imaging is to handle the electrical crosstalk induced during transmission. Electrical cross talk in terms of transient currents may also impose problems for pulsed wave (PW) systems, e.g. in near field imaging where the recovery time of the electronics after pulse firing is critical. Presently, a digital cancellation network is investigated experimentally on a single transducer setup. The purpose of this network is to obtain a viable single transducer receive-and-transmit configuration through reduction of capacitively induced current. The proposed network is tested on coded Golay sequences and yields a marked increase in signal-to-clutter ratio compared to a conventional pulse train sequence.