Abstract: Disclosed is a multiterminal acoustic surface wave transducer which has a unidirectional response characteristic over a selected operating frequency band and is capable of launching and receiving surface waves in a body of piezoelectric material. In a specific embodiment the transducer includes a plurality of sets of first, second and third parallel electrodes arranged in cascade on a surface of the piezoelectric material with a center-to-center electrode spacing equal to one-third wavelength of a selected frequency within the frequency band. Corresponding electrodes in each set are interconnected, with each group of interconnected electrodes forming a terminal of what is in this case a three terminal transducer. When a three phase electrical signal is supplied to the terminals of the transducer with a 120.degree. phase separation between terminals, the transducer will launch a corresponding surface wave in the piezoelectric material in the direction of phase progression among the electrodes.