Patent ID: 6522047
Filing Date: 2003-02-18
Classification: H03H

Abstract:
An ultrasonic signal processor operated at multiple frequencies comprising:a nonpiezoelectric plate; an input IDT with a dispersive type of electrode-finger pattern, and having an overlap length L and interdigital periodicities Pi (i=1, 2, . . . , m); an output IDT with a dispersive-slant type of electrode-finger pattern, and having the electrode-finger direction slanting to that of said input IDT by an angle &thgr;, and also having an overlap length LP along said electrode-finger direction of said output IDT and interdigital periodicities Qi (i=1, 2, . . . , m) along the orthogonal direction to said electrode-finger direction of said output IDT; a first piezoelectric substrate; and a second piezoelectric substrate, said input- and output IDTs, and said first- and second piezoelectric substrates forming a transducer-unit, said input IDT receiving one of input electric signals Si (i=1, 2, . . . , m) with frequencies fi (i=1, 2, . . . , m) corresponding to said interdigital periodicities Pi, respectively, exciting a SAW in said first piezoelectric substrate, and transmitting said SAW to said second piezoelectric substrate along an upper end surface of said nonpiezoelectric plate, said output IDT transducing said SAW to electric signals Ej (j=1, 2, . . . , n), of which the phase delays linearly correlate to SAW propagation lanes Wj (j=1, 2, . . . , n) between said input- and output IDTs on said upper end surface of said nonpiezoelectric plate.