摘要
In this work, we present a 900 MHz low phase noise (PN) acoustic delay line (ADL) oscillator based on a LiNbO3/ SiO2/ Sapphire (LNOS) functional substrate and a low-noise RF amplifier, achieving an impressive close-in figure-of-merit (FOM) of 210 dB at 10-kHz offset. Since a large group delay (τG) is essential for reducing PN in delaybased oscillators, a 937 MHz low-loss shear-horizontal surface acoustic wave (SH-SAW) ADL with insertion loss (IL) of 11 dB and τG of 487 ns is implemented as the frequency-selective element. The oscillator achieves high-FOM, low-PN operation, demonstrating close-in PN of 104.8 dBc/ Hz(FOM=204 dB) at 1-kHz offset and -130.7 dBc/Hz(FOM=210 dB) at 10-kHz offset, with 12 kHz to 20 MHz integrated jitter <; 28.9 fs. The proposed LNOS SAW oscillator competes favorably with state-of-the-art microacoustic RF oscillators in terms of close-in FOM. © 2026 IEEE.