1. General

1.1 Applications

The appearance of the first piezoelectric transformers coincided with the development, in the 1950s, of ferroelectric ceramics of the perovskite crystalline family. It was in 1956 that C.A. Rosen [16] proposed a step-up transformer structure, fabricated in a bar of barium titanate (BaTiO ₃ ), which demonstrated the interest of making, very simply, compact electrical transformers, of small dimensions and with good performance. However, the impact of this demonstration had, at the time, only a very modest echo in terms of industrial applications.

It was undoubtedly the new preoccupation with device miniaturization, but also progress...