A surface acoustic wave device that can operate in alternate-phase mode and single-phase mode, and thus generate surface acoustic waves at two different frequencies. The device is based on a piezoelectric film deposited on an elastic substrate, and includes an electrode layer patterned as two interdigital electrodes and electrical source (2). The device is operated in alternate-phase mode by connecting the two electrodes to different ends of an electrical source (22). The device is operated in single-phase mode by connecting the two electrodes to the same end of an electrical source.
