Frequency stability of high performance SAW oscillators

Recent advances in the short-term and long-term the frequency stability of SAW (surface acoustic wave) oscillators are reviewed. Recent advances include the ability to set accurately the frequency of AW resonator, as well as significant improvements in the frequency stability of SAW oscillators. Phase noise floors of -184 dBc/Hz in 500-MHz SAW resonator oscillators, along with flicker noise levels of -83 dBc/Hz at a 10-Hz carrier offset, have been achieved. Prototype 400-MHz SAW delay line oscillators with tuning ranges of ±150 kHz have demonstrated noise floors of -170 dBc/Hz and flicker noise levels of -70 dBx/Hz at 10-Hz offset. Vibration sensitivities at the SAW device level of a few parts in 10¹⁰/g have also been measured. Recently, similar vibration sensitivities have been measured on a 900-MHz hybrid circuit SAW resonator oscillator. The long-term frequency stability of properly fabricated 500-MHz SAW resonator oscillators is consistently better than ±1 ppm/year