石英晶体谐振器和振荡器(byVig)详解.ppt

“QUARTZ CRYSTAL RESONATORS AND OSCILLATORS For Frequency Control and Timing Applications - A TUTORIAL” Rev. , by John R. Vig, November 2008. T. L. Anderson, R. E. Newnham and L. E. Cross, Coercive Stress for Ferrobielastic Twinning in Quartz, Proc. 31st Annual Symposium on Frequency Control, pp. 171-177, 1977, AD-A088221. Proc. copies available from NTIS. “QUARTZ CRYSTAL RESONATORS AND OSCILLATORS For Frequency Control and Timing Applications - A TUTORIAL” Rev. , by John R. Vig, November 2008. C. Frondel, The System of Mineralogy, Vol. III, “Silica Minerals”, John Wiley and Sons, Inc., New York, 1962. “QUARTZ CRYSTAL RESONATORS AND OSCILLATORS For Frequency Control and Timing Applications - A TUTORIAL” Rev. , by John R. Vig, November 2008. - Shown above is the phase diagram for single crystal silica, SiO2. The Y-axis shows pressure in gigapascals. The temperature of phase transition between a-quartz and b-quartz increases with increasing pressure. The a-b transition temperature is 573oC at one atmosphere pressure. It increases to about 600oC at the typical pressures used for growing quartz in autoclaves. In frequency control applications, only a-quartz is used. R. B. Susman, The Phases of Silica, Rutgers Univ. Press, New Brunswick, NJ 1965. C. Frondel, The System of Mineralogy, Vol. III, “Silica Minerals”, John Wiley and Sons, Inc., New York, 1962. “QUARTZ CRYSTAL RESONATORS AND OSCILLATORS For Frequency Control and Timing Applications - A TUTORIAL” Rev. , by John R. Vig, November 2008. Ever since quartz became the material of choice for crystal oscillators (in the 1920s), researchers have been looking for materials that are even better than quartz. Many materials have looked promising, e.g., berlinite, lithium tetraborate, and gallium phosphate, but nothing has equaled quartz. Langasite (also called LGS) and its isomorphs, langanite (LGN), langatate (LGT), etc. look highly promising. Some of the possible consequences of the improved properties o