Electronic scanning of sonar beam from a phased array of acoustic transducers controlled through programmable digital delay lines

Electronic scanning of the beam with phased arrays is faster compared to rotating antennas, and with the phased arrays kept stationery, the beam could be shifted in a manner as desired by the system by controlling the phases. By and large, delay lines are used for producing the necessary phase shifts for the array elements. The use of digital delay lines improve further the rate of scanning and avoids the installation of bulky acoustic delay lines whose performance characteristics are affected by the environment in which it is operated. The recently reported digital delay line has simplicity in controlling the delay lengths from a single analog source. This project employs that digital delay line for scanning the beam in linear directions and also for scanning a sector like raster scanning. The implementations and performance characteristics are reported.