4D-3 A 2 GHz Reference Oscillator incorporating a Temperature Compensated BAW Resonator

A reference oscillator operating at 2 GHz and based on a temperature compensated bulk acoustic wave resonator is presented. Temperature compensation is realized by addition of an extra SiO₂ layer in the resonator. The temperature drift of the resonance frequency of the resonator is -5 ppm/K. The oscillator circuit has the Butler topology and uses the BAW resonator at series resonance. The demonstrator incorporating a high impedance resonator shows a low phase noise: -99 dBc/Hz and -120 dBc/Hz at 10 kHz and 100 kHz offset, respectively. The drift of the oscillator frequency with temperature is almost linear and almost equal to that of the stand-alone resonator. The supply voltage dependence is 100 ppm/V in this oscillator