Book Description

Piezoelectric resonators rank among the traditional electronic components that have been used for many years in radioelectrics, time-keeping and, more recently, in microprocessor-based devices. Their ever-increasing range of application has been made possible by gradual improvements in the basic resonator parameters. This book is a compendium of studies on bulk-wave vibrating piezoelectric resonators. First published in Czech in 1983, this English edition has been adapted to include the latest concepts and developments. Important elastic, dielectric and piezoelectric parameters of piezoelectric resonators are reviewed, and basic characteristics of modern piezoelectric crystals and piezoceramic materials derived. In the section on vibration theory, the equations of motion and their solutions are presented; the resonant frequency equations of the flexural, length extensional and torsional modes of vibrations of the bars and the thickness vibrations of the plates are derived. Approximate methods of calculation for contoured rectangular plates are also considered. The electrical equivalent circuit of piezoelectric resonator is then derived for various shapes of bars and plates. The properties of the electrical equivalent circuit are described with regard to the influence of the temperature and the non-linear properties of piezoelectric crystals. The methods of measurement of resonant frequency and dynamic capacitance are presented and related to the equivalent electrical circuit of piezoelectric resonators. One part of the book is devoted to basic types of piezoelectric quartz, LiNbO3 and LiTaO3 resonators. Special attention is given to the possibility of adjusting the resonant frequency/temperature characteristics by selecting a suitable orientation angle and dimension ratio of the resonator plate. A brief description of multi-resonator structures is included. Production technology and comments on resonator applications in wave filters and crystal oscillators are also discussed. The book is intended for engineers in research and development departments in plants producing piezoelectric resonators, as well as for those who utilize piezoelectric units in various electronic and measuring devices. University and postgraduate students may find it a useful source of information in a number of electrotechnical and electronic studies.