Performance Verification of Injection Locked STW Clocks with BAW Crystal Stability

This work verifies the expected phase noise and medium-term stability improvement of recently proposed 1 GHz surface transverse wave (STW) injection locked clocks operating on 1.25 V supply voltage with bulk acoustic wave (BAW) crystal stability. Compared to a free running STW oscillator, temperature stability improvement by a factor of 16 and close-in phase noise reduction by 18 to 25 dB is demonstrated. A high-power version of the system consumes 90 mA of DC current, generates 4 dBm of output power at 1 GHz and provides a thermal noise floor of -174 dBc/Hz. A low-power version demonstrates safe lock and integrated r.m.s. jitter of 220 to 640 fs over a (0 to +85)degC temperature range. Data on phase noise, output power and frequency sensitivities to supply voltage variations over temperature are provided and discussed. Ways for potential improvement of system performance are suggested.