1994•Unpublished venueRequires access
A steerable Doppler probe using unidirectional SAW transducer
Matsunaka, Tabuchi
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Abstract
A steerable Doppler probe using a unidirectional surface acoustic wave transducer with leaky wave is presented for application to the measurement of blood flow. The SAW transducer having the interdigital electrodes in a shape such as a circular-arc is fabricated on the PZT ceramics with dimensions 4.5 mm×4.0 mm. The pitch between the electrodes of the transducer becomes wider gradually toward their other edges. Resonance frequencies of the experimental SAW transducer, therefore, are changed from 3.5 MHz to 15 MHz along the circular-arc electrodes, and hence the steering angle of the acoustic beam for the transducer varies from -68 degrees to 20 degrees. The fluctuation in conversion efficiency of the transducer was within -3 dB at the frequencies in the range of 4~11 MHz, and the -3 dB acoustic beam radiation angle was about 8.5 degrees at the frequency of 7 MHz