A unidirectional transducer for a surface acoustic wave (SAW) device. In
one embodiment the device includes (1) a defined area on a piezoelectric
substrate within which is located an open circuit reflector perpendicular
to the SAW direction of propagation; and a pair of low reflectivity
transducer electrodes located within the defined area and connected to
opposing bus bars, the electrodes perpendicular to the direction of the
SAW propagation and positioned with the excitation center of the pair of
electrodes located about seven-eighths of a Rayleigh wavelength at a
center frequency of the SAW from the reflector.