Abstract: An interdigital transducer for a surface-acoustic-wave resonator includes a conductive grid and a plurality of practical electrodes. The conductive grid includes a bus bar, a plurality of dummy electrodes and a conductive bar. The bus bar has a signal transmission terminal, and is disposed on a first side of the first conductive grid. The plurality of dummy electrodes directly extend from the bus bar. The conductive bar is disposed on a second side of the first conductive grid, and is opposite to the bus bar. Each of the plurality of practical electrodes extends from the conductive bar.