Piezoelectric Effect and Applications in Electrical Communication

The phenomenon of piezoelectricity, discovered in 1880, is the basis of a number of devices which are essential to the art and practice of electrical communication. The discovery of the phenomenon, the development of the quartz resonator, and its application as a frequency-stabilizing element in oscillator and filter circuits are described. Some of the technical problems encountered in the design and fabrication of quartz-crystal units are discussed. Using quartz crystal units for short-term stability and atomic resonators for long-term stability, frequency standards which are reliable and reproducible to 1×10-11 are now available.