a lanthanum gallium niobate single crystal substrate , referred to as langanite , has a prescribed range of euler angles for substrate and crystal orientation for improving signal processing for a surface acoustic wave device . when a voltage is applied to an input interdigital transducer of the saw device , a surface acoustic wave is generated in the langanite piezoelectric substrate . the surface acoustic wave propagates in a direction generally perpendicular to electrodes of the idt . the langanite crystal cut and wave propagation directions are defined which reduce insertion loss and frequency response distortion due to saw transduction , diffraction , and beam steering , while achieving improved temperature stability saw device as compared to other commonly used crystal substrates . a low power flow angle and reduced level of diffraction is also achieved .