DocumentCode :
2231638
Title :
A study of sidelobe reduction for limited diffraction beams
Author :
Jian-yu Lu ; Greenleaf, James
Author_Institution :
Dept. of Physiol. & Biophys., Mayo Clinic & Found., Rochester, MN
fYear :
1993
fDate :
31 Oct-3 Nov 1993
Firstpage :
1077
Abstract :
Limited diffraction beams have a large depth of field and are approximately depth-independent, even if they are produced with a finite aperture. Therefore, they may have applications in medical imaging, tissue characterization, nondestructive evaluation of materials, as well as other physical branches such as optics and electromagnetics. However, limited diffraction beams have larger sidelobes than those of conventional beams at their focuses. A method has been proposed for reducing the sidelobes of limited diffraction beams at the expense of frame rate. The authors study the efficacy of the method when stepwise aperture weighting functions are used to produce the beams. Results show that the method works well with a transducer of only 14 rings and 16 sectors. The transducer has a 25 mm diameter and 3.5 MHz central frequency, and can produce a pulse-echo response that maintains a -6-dB mainlobe width of about 1.83 mm over a depth of field of about 150 mm
Keywords :
biomedical ultrasonics; focusing; patient diagnosis; -6 dB; 1.83 mm; 150 mm; 25 mm; 3.5 MHz; limited diffraction beams; medical diagnostic imaging; medical imaging; nondestructive evaluation; pulse-echo response; sidelobe reduction; stepwise aperture weighting functions; tissue characterization; Apertures; Biological materials; Biomedical imaging; Biomedical optical imaging; Electromagnetic diffraction; Focusing; Frequency; Optical diffraction; Optical materials; Transducers;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium, 1993. Proceedings., IEEE 1993
Conference_Location :
Baltimore, MD
Print_ISBN :
0-7803-2012-3
Type :
conf
DOI :
10.1109/ULTSYM.1993.339601
Filename :
339601
Link To Document :
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