An ultrasonic wave sensor wherein the transmitter and receiver include a linear array of transducers. Each of the transducers of the transmitter are driven by plural pulsed signals in each of a plurality of intermittent time periods. The timing of the pulsed signals to each of the transducers is controlled to produce wave fronts that interfere to produce combined wave fronts at angles to the array of transducers. Three-phase charge coupled devices in conjunction with three-phase clocking pulses are used to produce pulsed signals of predetermined delays to each of the transducers. The receiver uses three-phase charge coupled devices and three-phase clocking pulses to process returned signals.