Patent ID: 7034634

Claim:
A surface acoustic wave (SAW) resonator comprising: a piezoelectric substrate: an interdigital transducer (IDT) electrode formed on said piezoelectric substrate; and a reflector electrode disposed adjacent to said IDT electrode; wherein said IDT electrode comprises: a plurality of first finger-electrodes; a plurality of second finger-electrodes; a plurality of strip-line electrodes; a first bus-bar electrode coupled to said first finger-electrodes; and a second bus-bar electrode coupled to said second finger-electrodes; wherein said first finger-electrodes and said second finger-electrodes do not overlap with each other, but are acoustically coupled together by said strip-line electrodes, wherein said strip-line electrodes overlap with at least one of said first finger-electrodes and said second finger-electrodes, wherein said IDT electrode and said reflector electrode form at least two resonating units, wherein said at least two resonating units are coupled in series via said strip-line electrodes, wherein said IDT electrode further comprises a plurality of dummy electrodes respectively disposed between said first finger-electrodes and said second finger-electrodes such that each of said dummy electrodes faces a respective one of said strip-line electrodes, and wherein each of said dummy electrodes has a width greater than that of each of said first finger-electrodes and that of each of said second finger-electrodes.