Characteristics of an Ultrasonic Array Transmitter in the Short Range

An ultrasonic array transmitter (12 × 12) has been developed and its theoretical studies were conducted in the short range. In the far field (>5 m), sound pressure level decreases exponentially with the distance. We have studied the effects of short pulse modulation on the array transmitter in the range from 0.5 m to 2 m to compare with our theoretical results. The sound pressure amplitude reduction in this region by 1/r does not follow the same as in the case of far field. The sound pressure level at 1 m wasabove 143 dB which can be considered to be useful for the biomedical applications.We also studied the normal reflected pulse from living and non-living object.