Switch-less dual-frequency reconfigurable CMOS oscillator using one single piezoelectric AlN MEMS resonator with co-existing S0 and S1 Lamb-wave modes

For the first time, this work demonstrates a switch-less dual-frequency (472-MHz and 1.94-GHz) reconfigurable CMOS oscillator using a single piezoelectric AlN MEMS resonator with co-existing S0 and S1 Lamb-wave modes of vibration. High performances (high Q and k_t² for a resonator and low phase noise for an oscillator) have been achieved for both the resonator and oscillator in terms of dual-mode operation. Especially, the 1.94-GHz operation has the best phase noise performance when compared with all previously reported CMOS oscillators that work at a similar frequency.