Patent ID: 7109828

Claim:
A surface acoustic wave (SAW) device comprising: a piezoelectric substrate cut out at a cut-angle allowing excitation of a leaky surface acoustic wave (LSAW); and an electrode pattern formed of an inter-digital transducer (IDT) electrode prepared on said piezoelectric substrate, said IDT electrode having at least a pair of finger-electrodes meshing with each other, wherein a pitch p (m) of said finger-electrodes satisfies a relation of 2×p≦vb/f, where vb (m/s) is a phase velocity of a slow shear wave propagating on said piezoelectric substrate, and f(Hz) is a resonance frequency of said SAW device, and said piezoelectric substrate has a step and said finger-electrodes of said electrode pattern are formed on a top of said step on said piezoelectric substrate, said step having a pitch similar to the pitch p.