Even a wire fence can be detected if it is close enough. The main characteristics of ultrasonic sensors for rear sonar are directivity, ringing time, sensitivity and sound pressure. Directivity of an ...

However, once fabricated, these properties, including diffusion directivity ... between two glass discs, and an ultrasonic piezoelectric transducer. The electrodes of the transducer are distributed in ...

However, once fabricated, properties such as diffusion directivity ... ultrasonic piezoelectric transducer embedded in the device. The transducer's electrodes are arranged in a circular pattern ...