Fundamental Noise Studies of Quartz Crystal Resonators

The s t u d i e s o f q u a r t z c r y s t a l o s c i l l a t o r f r e q u e n c y i n s t a b i l i t i e s show t h e y a r e n o t e n t i r e l y due t o e l e c t r o n i c s n o i s e b u t t h e q u a r t z r e s o n a t o r i t s e l f must be considered as a noise source. The prev ious inves t igat ions o f resonator f requency no ises (g iven by F. Walls) gave an i m p o r t a n t i n d i c a t i o n a b o u t t h e i r l e v e l s . T h i s work p resents the resu l ts o f measurements o f frequency f l u c t u a t i o n s o f q u a r t z r e s o n a t o r s used as pass ive fourpo r t s . The n o i s e i s c h a r a c t e r i z e d i n t h e f r e q u e n c y domain.