Abstract: The elastic surface wave device is comprised of an inter-digital transducer, a multi-strip coupler or a hone type acoustic beam width compresser, and an output terminal which are formed on a piezo electric substrate. The inter-digital transducer can produce an elastic surface wave signal which has a predetermined delay time, an electrode width equal to and u band width BW equal to ##EQU1## The hone type acoustic beam width compresser can produce the mixed effect of non-linearity by transferring maximum energy in accordance with the proportion of the input acoustic beam width l.sub.1 and the output acoustic beam width l.sub.2 to increase the acoustic power density. The multi-strip coupler can filter low band frequencies by spatially integrating the electrical displacement of the elastic surface wave according to the electrode length of the output side.