Patent ID: 6540683
Filing Date: 2003-04-01
Classification: A61B,B06B,G01S

Abstract:
A dual-frequency ultrasonic array transducer comprising:a first set of piezoelectric elements operable at their center resonant frequency to transmit ultrasonic pulses at a fundamental frequency; a second set of piezoelectric elements operable at their center resonant frequency to receive ultrasonic pulses at a second frequency which is either twice the fundamental frequency (harmonic) or half the fundamental frequency (primary subharmonic), wherein said first set of piezoelectric elements and said second set of piezoelectric elements are positioned in a linear alternating sequence; an acoustic-damping backing layer; electrical contacts bonded to the front and back of each piezoelectric element; multiple acoustic impedance matching layers of one-quarter wavelength of the higher said center resonant frequency, wherein the number of said acoustic impedance matching layers is equal to or twice the ratio of the higher of said center resonant frequency to the lower said center resonant frequency; and an acoustic lens.