Patent ID: 6070468
Filing Date: 2000-06-06
Classification: G01N,G10K

Abstract:
A leaky wave transducer configured to provide high efficiency ultrasonic leakage into a fluid medium having low acoustic impedance, comprising:a plate of a material in which an A0 Lamb wave mode excited therein (a) is dispersive with a range of phase velocities that approximately encompasses the velocity of sound in the fluid medium and (b) which has a high attenuation;said plate having a thickness d such that the product fd of the thickness d and frequency f of the A0 Lamb wave mode determines a plate attenuation/bandwidth mode selected from (a) very high attenuation with narrow bandwidth or (b) the high attenuation with wide bandwidth, wherein the very high attenuation approximately equals peak attenuation and the high attenuation includes a range of attenuation values near but not encompassing the peak attenuation with high absolute values and small variation across the range; anda plate length l such that the product .alpha.l of the length l and a leak coefficient .alpha. equals 1.