Mechanical and acoustic effects in low phase noise piezoelectric oscillators

Improvements in the design and realization of hardened oscillators are proposed to make the piezoelectric equipment insensitive to mechanical or acoustic disturbances. Following extensive experimentation, the following conclusions were reached: the improvement of g sensitivity is a long and expensive process; for a given industrial state of the art, it is preferable to preserve the phase noise characteristics during vibrations by using mechanical absorber structures such as a filter; in order to obtain the same results without absorbers, g sensitivity of some 1.10/sup -12//g would be necessary. However, very close to the carrier frequency, the phase noise during vibrations depends directly on the g sensitivity of the resonator, for either quartz or lithium tantalate.<>