A low-power dynamic variable-gain amplifier for ultrasonic imaging systems
Abstract
A monolithic silicon integrated-circuit variable-gain amplifier was fabricated, which has no external parts, a minimum of noise, precisely controlled dynamically variable gain, low power consumption, and wide bandwidth. The amplifier is based on ion-implanted junction field effect transistors (JFETs) and is to be applied in a unique high-resolution real-time three dimensional ultrasonic imaging system (ULISYS) for medical diagnosis. Variable-gain amplifier techniques were analyzed for lower power drain and noise, high gain precision, and a large signal-handling capacity. A breadboard simulation of the amplifier was performed, and measurements confirmed the theoretical analysis. Possible integrated JFET structures were computer simulated, and the sensitivities of JFET electrical parameters to variations in the processing parameters were calculated.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1978
- Bibcode:
- 1978PhDT........78L
- Keywords:
-
- Amplifier Design;
- Amplifiers;
- Imagery;
- Ultrasonics;
- Computerized Simulation;
- Fabrication;
- Field Effect Transistors;
- Ion Implantation;
- Medical Science;
- Electronics and Electrical Engineering