Reconfigurable 4-frequency CMOS oscillator based on AlN Contour-Mode MEMS resonators

This paper reports on the first demonstration of a reconfigurable Complementary Metal Oxide Semiconductor (CMOS) oscillator based on MicroElectroMechanical System (MEMS) resonators operating at 4 different frequencies (268, 483, 690 and 785 MHz). A bank of multi-frequency switchable AIN Contour-Mode MEMS resonators (CMRs) were connected to a single CMOS oscillator circuit that can be configured to selectively operate in 4 different states with distinct oscillation frequencies. The phase noise (PN) of the reconfigurable oscillator was measured for each of the 4 different frequencies of operation showing values between -94 and -70 dBc/Hz at 1 KHz offset and PN floor values as low as -165 dBc/Hz at 1 MHz offset. Jitter values as low as 114 fs-rms (integrated 12 KHz 20 MHz) and switching times as fast as 20 μs were measured. This first prototype represents a miniaturized solution (30X smaller) over commercially available Voltage Controlled SAW Oscillators (VCSOs) and potentially has the advantage of generating multiple stable frequencies without the need of cumbersome and power consuming phase locked loop (PLL) circuits.