A Temperature-Stable Film Bulk Acoustic Wave Oscillator

This letter reports a passively temperature-compensated CMOS oscillator utilizing a film bulk acoustic resonator. The resonator exhibiting an f ldr Q product of 2-4 X 10
¹²
s
^-1
is composed of molybdenum, aluminum nitride, and a compensation material that has a positive temperature coefficient of Young's modulus. The 604-MHz oscillator consumes 5.3 mW from a 3.3-V supply and achieves excellent phase noise performances of -102, -130, and -149 dBc/Hz at 1, 10, and 100 kHz carrier offsets, respectively. The oscillator's temperature-dependent frequency drift is less than 80 ppm over a temperature range of -35degC to +85degC.