Reconfigurable MEMS-enabled LC-tank for multi-band CMOS oscillator

A wide frequency span reconfigurable MEMS-enabled LC-tank network for a multi-band RF oscillator is implemented, made of ohmic RF-MEMS switches, spiral suspended inductors and metal-insulator-metal (MIM) capacitors all integrated on a high resistivity silicon MEMS substrate. The LC-tank is connected to a differential cross-coupled n-MOS pair on a separate CMOS substrate, by chip-on-chip integration and wire bonding, leading to the complete MEMS-CMOS oscillator prototype. The separate LC-tank and the complete oscillator are both tested on-wafer through RF-probing. Measurement results show two resonance frequencies of 1.375 GHz (Q = 7.2) and 3.605 GHz (Q = 14.4) for the MEMS-enabled LC-tank. The MEMS-CMOS oscillator shows a phase noise of -124.5 dBc at 1MHz frequency offset, with 3mA bias current at 1.2 V power supply. Overall oscillator performances well compare with state-of-the-art non-reconfigurable CMOS oscillator designs.