Chapter VI: Modes of motion in quartz crystals, the effects of coupling and methods of design

WITH the recent extended use of Quartz crystals in oscillators and electrical networks has come a need for a comprehensive view of the various types of crystal cuts. In addition there has been a need for illustration of some of the methods employed in choosing the proper cut for a given requirement, the manner in which quartz crystals vibrate and the basic principles governing the choice of a design to use certain cuts most advantageously. In particular one of the greatest problems associated with the recent large scale production of crystals for oscillator purposes has been that of obtaining crystals the activity and frequency of which would not vary to any large degree over a wide range in temperature.