Extremely low-phase-noise SAW resonators and oscillators: design and performance

Area of Science:

• Electrical Engineering
• Materials Science
• Physics

Background:

• Achieving low phase noise in oscillators is critical for high-performance RF and microwave systems.
• Traditional surface acoustic wave (SAW) oscillators face limitations in phase-noise performance, especially at higher frequencies.

Purpose of the Study:

• To develop prototype low-noise SAW resonator oscillators with state-of-the-art phase-noise performance.
• To demonstrate significant phase-noise reduction across the spectrum (white, flicker, and random-walk FM).

Main Methods:

• Utilized advanced SAW resonator designs including overmoded, very wide, and dual apertures.
• Employed modified fabrication techniques to enhance resonator performance.
• Implemented a novel high-power RF burn-in procedure (>27 dBm) to mitigate noise.

Main Results:

• Demonstrated state-of-the-art phase-noise performance at fundamental frequencies (400-600 MHz) and after 16x frequency multiplication to X-band.
• Achieved an overall reduction in white $\phi_M$, flicker FM, and random-walk FM noise.
• Showcased prototype oscillators capable of handling incident RF power > +20 dBm.
• Reported a 5- to 15-dB improvement in the overall phase-noise spectrum.

Conclusions:

• Advanced SAW resonator designs and fabrication techniques significantly reduce oscillator phase noise.
• High-power RF burn-in is an effective method for lowering flicker and random-walk FM noise.
• The developed SAW resonator oscillators offer superior phase-noise performance for demanding applications.