4. Thin-film volume-wave resonators and filters (FBARs)

4.1 A brief history of volume wave devices

The discovery of the piezoelectric effect ("pressure electricity", as its Greek root suggests) by the Curie brothers in 1881 [39] aroused only moderate enthusiasm in the scientific community, and it was not until more than thirty years later that the first use was made of it by Langevin, among others, for the development of the first SONAR (SOund NAvigation and Ranging ) [40] . At the same time (1919), a patent was filed by Nicolson [41] of the Bell Telephones laboratories, describing...