Surface wave dispersive acoustic delay line

Claim 1

A surface acoustic wave device for dispersing surface waves of a speed v operating in a frequency band of f min and f max comprising: a substrate for supporting surface acoustic waves; an input transducer means of the multi-electrode oblique alignment type having variable interval interdigital electrodes for producing acoustic waves; an output transducer of the multi-electrode oblique alignment type having variable interval interdigital electrodes mounted so that the slope of said input and said output transducers are equal and are disposed symmetrically about a point on the Z'--Z axis of said substrate for receiving said acoustic waves; and two variable interval slating grating means for reflecting said acoustic waves and, wherein the interval between said interdigital electrodes of said input and output transducers is between (nv/2f min ) and (nv/2f max ) with n being an integer, and the two dispersive reflective gratings are slanted and the distance between said corresponding reflectors are respectively between (kv/f min ) and (kv/f max ) with k being another integer whose value is different from said value of n.