Simulation and Measurement of Air-Coupled Semi-Circular and Conical PVDF Sensors

Abstract

For airborne sound navigation and ranging (SONAR) applications, low frequency and broadband transducers are required for the detection of obstacles with high axial resolution. In this paper, electrical and mechanical characteristics of semi-circular sensors and a semi-conical polyvinylidene fluoride (PVDF) sensor are compared through simulations and experiments. First, the implementation of semicircular transducers and semi-conical transducer is presented. The electrical pulse, sine responses, dielectric impedance spectroscopy, and beam pattern measurements of transducers are achieved and compared. The vibration analysis of produced sensors was performed by a finite-element method and compared with experimental results. Experiments and simulations show that the semi-conical PVDF transducer has a higher bandwidth than the semi-circular transducers and it is suitable for low-frequency airborne pulse-echo ultrasound applications using single pulse or frequency chirped wave transducer.