Patent ID: 8264126

Claim:
An ultrasonic transducer comprising: a piezoelectric element having a characteristic acoustic impedance; a front acoustic impedance converter coupled to said piezoelectric element, said front acoustic impedance converter comprising: a front polymer layer having a thickness t p1 coupled to said piezoelectric element; and a front metal layer for transmitting acoustic energy between said front polymer layer and a propagation medium having a characteristic acoustic impedance, said front metal layer having a thickness t m1 and being coupled to said front polymer layer, wherein said front polymer layer is arranged intermediate said piezoelectric element and said front metal layer such that there is no contact between said piezoelectric element and said front metal layer, wherein said characteristic acoustic impedance of said propagation medium is lower than said characteristic acoustic impedance of said piezoelectric element, and wherein said front acoustic impedance converter has an effective characteristic acoustic impedance Z C between said piezoelectric element and said propagation medium characteristic acoustic impedances.