A Ku-Band Oscillator Utilizing Overtone Lithium Niobate RF-MEMS Resonator for 5G

This letter presents a 12.9-GHz silicon germanium (SiGe) Pierce oscillator using a third antisymmetric overtone in a lithium niobate (LiNbO3) resonator for 5G communications. Quarter-wave resonators are used to satisfy the Barkhausen oscillation conditions for the third overtone while suppressing the fundamental and higher order resonances. The oscillator achieves a measured phase noise of -70 and -111 dBc/Hz at 1 and 100-kHz offsets from a 12.9-GHz carrier while consuming 20 mW of dc power. The oscillator achieves a figure-of-merit of 200 dBc/Hz at 100-kHz offset, surpassing the state-of-the-art electromagnetic (EM) and overtone MEMS oscillators. The achieved oscillation frequency is the highest reported to date for an MEMS oscillator. The demonstrated performance shows the strong potential of microwave acoustic oscillators for 5G frequency synthesis. This work will enable low-power 5G transceivers featuring high speed, high sensitivity, and high selectivity in small form factors.