Japan Journal of Applied Physics. 2014 Jun;53(7S):07KC03; http://dx.doi.org/10.7567/JJAP.53.07KC03
The lateral resolution of a parametric acoustic array with narrow directivity is expected to be superior to that of a conventional linear sound source. The range resolution of the parametric array, however, is as low as the resolution of the linear source because of its long wavelength. To improve the range resolution in maintaining a high azimuth resolution for parametric sounds, a pulse compression technique using linear frequency-modulated signals or chirp signals is explored in the present study. The generation of chirp-modulated parametric sounds was experimentally confirmed in water, and then the auto-correlation of the parametric sound demonstrates short pulse widths up to 1/10 of the primary pulse duration. The results reveal that the pulse compression is feasible for a low-frequency parametric sound source with narrow directivity in the same manner as the compression of a linear sound wave.
This work was performed in the Kamakura Laboratory, The University of Electro-communications, Tokyo
Copyright © 2014 The Japan Society of Applied Physics.
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Clinic Ultrasound Laboratory (クレメント超音波研究室)
Cleveland Clinic (クリーブランド・クリニック),
Lerner Research Institute
Case Western Reserve University