A New Digital Phased Array System for Dynamic Focusing and Steering with Reduced Sampling Rate

Abstract

In order to enhance the resolution of the ultrasonic B-mode image, digital techniques for dynamic focusing and steering have been receiving a great deal of attention for a long time. In this paper, we present the theory and preliminary experimental results for a new architecture of a fully digital B-mode imaging system with this desired feature. The system employs the Pipelined-Sampled-Delay-Focusing (PSDF) scheme to eliminate the bulky memory addressing and interpolation circuits which are needed in conventional digital imaging systems. To reduce hardware requirements and the bandwidth required for digital processings, we describe an efficient method to generate the sampling clocks for dynamic focusing and steering and some modified bandwidth sampling techniques to reduce the sampling rate for signal digitization. Using these methods, it is possible to achieve dynamic focusing and steering in real-time sector imaging using a linear phased array.