A SINGLE PHASE UNIDIRECTIONAL SURFACE ACOUSTIC WAVE TRANSDUCER AND IMPROVED REFLECTORS

摘要

A unidirectional transducer (100) for a surface acoustic wave (SAW) device. In one embodiment the device includes a defined area on a piezoelectric substrate (150) within which is located an open circuit reflector (130) perpendicular to the SAW direction of propagation (170); and a pair of low reflectivity transducer electrodes (140) located within the defined area and connected to opposing bus bars (160), the electrodes (140) perpendicular to the direction of the SAW propagation (170) and positioned with the excitation center of the pair of electrodes (140) located about seven-eighths of a Rayleigh wavelength at a center frequency of the SAW from the reflector (130).