A B-mode diagnostic system using ultrasound is designed and implemented.
This system can be displayed in real time both B-and M-mode images simultaneously.
To obtain high resolution, dynamic focusing was employed and many problems associated with it are investigated and solved in this paper.
Specially, to eliminate switching noise generated in focal point changing, two signal paths are used alternately.
Also Pulser, low noise Preamp, Log-amp with wide dynamic range and STC circuit are designed.
As the result, lateral resolution has about 2 mm uniformly and switching noise did not appear in the normal operating condition.
Further, to compensate the frequency dependent attenuation, the dynamic filter was investigated.
