A BVA quartz crystal oscillator for severe environments

A BVA quartz resonator which has been developed for use in severe environments is discussed. More than one hundred units have been produced and tested in France and in the US. The resonator is a 10 MHz, 3^rd overtone SC cut crystal. The unit fits into an ordinary HC 40 can without pinch-off. Typical values are given as R₁=95 Ω, Q=1.35×10⁶, g maximum sensitivity is less than 10^-10/g. turnover point=85°C, and pressure variation sensitivity=5×10^-11/bar. The resonator design is briefly discussed and described. Results of various tests and experimental data on this resonator are given and discussed. A type of quartz oscillator which has been developed to take advantage of this resonator for use in severe environments is described. Phase noise and Allan variance for the oscillators is discussed