Bearing angle estimation for sonar micro-array using analog VLSI spatiotemporal processing

The authors describe an analog VLSI chip designed to extract incoming bearing angle from ultrasonic signals received by an array of microphones. The processing uses spatiotemporal filters to extract the velocity of a wavefront moving across the array, and from this velocity the incident angle is computed. Spatiotemporal filtering is far more compatible with fast, low-power circuits than are traditional discrete-time techniques. The chip was fabricated on a standard 3M2P CMOS process, with a 0.35 feature size. It consumes 0.93 mW of power during computation.