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DEVELOPMENT OF FRONT-END CIRCUITS FOR HIGH FREQUENCY
ULTRASOUND SYSTEM
by
Hojong Choi
A Dissertation Presented to the
FACULTY OF THE USC GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(ELECTRICAL ENGINEERING)
May 2012
Copyright 2012 Hojong Choi
Object Description
| Title | Development of front-end circuits for high frequency ultrasound system |
| Author | Choi, Hojong |
| Author email | hojongch@usc.edu;hojongchoi@yahoo.com |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Electrical Engineering |
| School | Viterbi School of Engineering |
| Date defended/completed | 2011-11-01 |
| Date submitted | 2012-04-06 |
| Date approved | 2012-04-06 |
| Restricted until | 2013-04-06 |
| Date published | 2013-04-06 |
| Advisor (committee member) |
Shung, K. Kirk Parker, Alice C. Chen, Yong Dapkus, P. Daniel |
| Abstract | This dissertation describes the development of a novel integrated preamplifier with a Sallen-Key Butterworth filter and novel bipolar transistor-based limiter for a high frequency ultrasonic transducer. First, the motivation for the integrated preamplifier results from the fact that the integrated preamplifier may reduce cable loss because the impedance matching with the high frequency transducer can affect the performance of the transducer due to cable loading effect. The design of an integrated circuit consisting of a preamplifier with the Sallen-Key Butterworth filter for a high frequency ultrasonic transducer will be presented. The This dissertation describes the development of a novel integrated preamplifier with a Sallen-Key Butterworth filter and novel bipolar transistor-based limiter for a high frequency ultrasonic transducer. First, the motivation for the integrated preamplifier results from the fact that the integrated preamplifier may reduce cable loss because the impedance matching with the high frequency transducer can affect the performance of the transducer due to cable loading effect. The design of an integrated circuit consisting of a preamplifier with the Sallen-Key Butterworth filter for a high frequency ultrasonic transducer will be presented. The front-end circuits consisting of integrated preamplifier with Sallen-Key Butterworth filter is usually interfacing with transducer and power amplifier such that the simulations and experiments with transducer and power amplifier is required to consider their effect to obtain proper performances. The simulation and experimental results of the integrated preamplifier and filter chain demonstrate the improved performances of pulse-echo response and wire-phantom imaging with a high frequency thick film (LiNbO3) transducer and thick film (PZT) array element transducer. The integrated preamplifier which had high frequency silicon germanium (SiGe) hetero-junction bipolar transistors (HBT's) was fabricated in an IBM 0.18 um bipolar complementary metal oxide semiconductor (BiCMOS) process. This implementation represents the first step in the eventual realization of a complete integrated high frequency receiving system. ❧ Second, high-frequency ultrasound imaging systems are not only dramatically affected by the electrical impedance mismatch between the transducer and the electronics but the attenuation caused by passive components of the protection devices and the system. These protection devices are used to protect the front-end circuits from the unexpected voltage signals induced by a transmitter. Therefore, to optimize the performances of the imaging system, there is a need to improve the design of these limiter circuits. These novel limiter circuits were analyzed with the small signal and large signal models of bipolar transistors. And, the improved performances of these limiters such as magnitude frequency responses, total harmonic distortions and total noise figures including preamplifiers were measured and compared with a commercial diode limiter. The capability of the novel limiters was also demonstrated through pulse-echo responses with a high frequency ultrasonic transducer. These new bipolar-transistor-based limiters may have applications for the high-frequency ultrasound imaging where both the bandwidth and signal to noise ratio are crucial. |
| Keyword | front-end circuits; high frequency ultrasonic transducer; high frequency ultrasound system; preamplifier; ultrasonic transducer; ultrasound system |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m |
| Contributing entity | University of Southern California |
| Rights | Choi, Hojong |
| Access conditions | The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the author, as the original true and official version of the work, but does not grant the reader permission to use the work if the desired use is covered by copyright. It is the author, as rights holder, who must provide use permission if such use is covered by copyright. The original signature page accompanying the original submission of the work to the USC Libraries is retained by the USC Libraries and a copy of it may be obtained by authorized requesters contacting the repository e-mail address given. |
| Repository name | University of Southern California Digital Library |
| Repository address | USC Digital Library, University of Southern California, University Park Campus MC 7002, 106 University Village, Los Angeles, California 90089-7002, USA |
| Repository email | cisadmin@usc.edu |
| Archival file | uscthesesreloadpub_Volume3/etd-ChoiHojong-579.pdf |
Description
| Title | Page 1 |
| Contributing entity | University of Southern California |
| Full text | DEVELOPMENT OF FRONT-END CIRCUITS FOR HIGH FREQUENCY ULTRASOUND SYSTEM by Hojong Choi A Dissertation Presented to the FACULTY OF THE USC GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (ELECTRICAL ENGINEERING) May 2012 Copyright 2012 Hojong Choi |
