A wideband annular piezoelectric composite transducer configuration with a graded active layer profile

Ultrasound technology is routinely used in many application areas including underwater sonar, biomedicine, non destructive evaluation (NDE), materials characterisation and process control - all with direct routes into the vital economic sectors of energy, transportation, healthcare and food and drink. As technology demands have increased, device manufacturers are faced with a constant need to extend bandwidth and/or frequency response, while at the same time improve sensitivity, all combined with minimisation of size, complexity and cost. It is becoming increasingly apparent that the current transducer technology, with its emphasis on multi-element array systems, is nearing saturation and new approaches to ultrasonic system design and operation are needed to satisfy many future demands. This paper presents wideband annular piezoelectric configuration with graded composite active layer.