Phase noise measurements of high overtone bulk acoustic wave resonators

In this paper, a passive measurement system is used to explore the phase noise of high overtone bulk acoustic wave resonators. The chosen overtone is around 373 MHz and the temperature coefficient of frequency at room temperature is 4 ppm/K. The 1/f noise is clearly shown and a flicker floor of about σ
_y
_
_floor
= 1.5×10
^-11
is demonstrated.