A 76.8?MHz temperature compensated MEMS reference oscillator for wireless handsets
This paper reports on the design of a low phase noise 76.8MHz AlN -on-silicon reference oscillator using SiO2 SiO 2 as temperature compensation material. The paper presents profound theoretical optimization of all the important parameters for AlN-on-silicon width extensional mode resonators, filling into the knowledge gap targeting the tens of megahertz frequency range for this type of resonators. Low loading CMOS cross coupled series resonance oscillator is used to reach the-state-of-the-art LTE phase noise specifications. Phase noise of ?123dBc/Hz at 1kHz, and ?162dBc/Hz at 1MHz offset is achieved. The oscillator?s integrated root mean square RMS jitter is 106fs (10kHz to 20MHz), consuming 850?A, with startup time of 250?s, and a figure-of-merit FOM of 216dB. This work offers a platform for high performance MEMS reference oscillators; where, it shows the applicability of replacing bulky quartz with MEMS resonators in cellular platforms.
temperature compensation mems phase noise series resonant oscillator cellular