Unidirectional dispersive transducers and applications to efficient elastic convolvers

Elastic convolvers are very important for signal-processing devices for spread-spectrum communication systems. The better efficient convolvers are required for the application of the devices. A chirp transducer which is one of the dispersive transducers, can give a comparatively low insertion loss and wideband property for the convolvers. The authors found the unidirectional property of the chirp transducer by taking account of reflection of surface acoustic waves (SAWs) caused by electrodes. The directivity is in the down-chirp direction. The unidirectional property and its application to elastic convolvers are described