A 2.6 GHz low phase-noise VCO monolithically integrated with high Q MEMS inductors

We present a fully-integrated high-performance VCO with on-chip MEMS inductors for the first time. The MEMS inductors have been realized from the proprietary CMOS-compatible MEMS process that we have developed to provide suspended thick metal structures for high Q inductors. Core CMOS VCO circuits including varactors have been designed and fabricated using by a commercially available TSMC 0.18 µm mixed-mode CMOS process. As post-CMOS processes, MEMS inductors have been monolithically integrated on the top of the CMOS core circuits. Low phase noise of -122 dBc/Hz has been achieved at 600 kHz offset from a resonant frequency of 2.6 GHz in the fabricated single chip VCOs.