Phase-error-free quadrature sampling technique in the ultrasonic B-scan imaging system and its application to the synthetic focusing system

Author

Chang, Seong Ho ; Park, Song Bai ; Cho, Gyu Hyoung

Author_Institution

Dept. of Electr. Eng., Korea Adv. Inst. of Sci. & Technol., Seoul, South Korea

Volume

40

Issue

3

fYear

1993

fDate

5/1/1993 12:00:00 AM

Firstpage

216

Lastpage

223

Abstract

The quadrature sampling technique as a means of detecting the envelope of RF waveform in the baseband is well known. If this technique is applied to a focused ultrasound imaging system using an array transducer, whether it is a synthetic or nonsynthetic focusing system, unwanted phase terms appear in the expressions of the inphase and quadrature components of the baseband signal when an appropriate delay time is introduced to each channel signal for the purpose of focusing. The expressions of the inphase and quadrature components from the point of focusing are derived and analyzed in detail, and a scheme to eliminate the unwanted phase terms is proposed. The resulting phase-error-free quadrature sampling technique is applied to the synthetic focusing system; a system block diagram together with the simulation and experimental results are presented.<>

Keywords

acoustic arrays; acoustic imaging; acoustic signal processing; biomedical ultrasonics; focusing; PEFQST; RF waveform envelope detection; array transducer; delay time; focused ultrasound imaging system; phase-error-free quadrature sampling technique; simulation; synthetic focusing system; ultrasonic B-scan imaging system; Baseband; Delay effects; Envelope detectors; Focusing; Phased arrays; Radio frequency; Sampling methods; Ultrasonic imaging; Ultrasonic transducer arrays; Ultrasonic transducers;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/58.216834

Filename

216834