Elastic wave delay device

Claim 1

AN ULTRASONIC DEVICE COMPRISING A BODY OF PIEZOELECTRIC MATERIAL, MEANS FOR LAUNCHING WITHIN SAID BODY AN ULTRASONIC WAVE HAVING A PARTICLE DISPLACEMENT THAT IS NORMAL TO ONE SURFACE OF SAID BODY AND THAT HAS A MAXIMUM AMPLITUDE AT SAID SURFACE DECREASING WITH DISTANCE AWAY FROM SAID SURFACE, ELECTRODE MEANS FOR COUPLING WITH SAID WAVE ON SAID SURFACE WHILE MAINTAINING THE INTEGRITY OF SAID WAVE, SAID LAST NAMED COUPLING MEANS INCLUDING A PLURALITY OF SPACED CONDUCTIVE MEMBERS PHYSICALLY SEPARATED FROM SAID ONE SURFACE BY A DISTANCE THAT IS SMALL COMPARED TO A WAVELENGTH OF SAID WAVE, SAID MEMBERS COMPRISING MEANS FOR DETECTNG A PIEZOELECTRIC FIELD NORMAL TO SAID SURFACE GENERATED BY SAID PARTICLE DISPLACEMENT AT A MULTIPLICITY OF SPACED POINTS ALONG THE DIRECTION OF PROPAGATION OF SAID WAVE, MEANS FOR ELECTRICALLY CONNECTING ALTERNATE ONES OF SAID MEMBERS TOGETHER TO FORM TWO ARRAYS, A LOAD IMPEDANCE, AND MEANS FOR CONNECTING EACH OF SAID ARRAYS TO OPPOSITE SIDE OF SAID LOAD IMPEDANCE.