VCO design for 60 GHz applications using differential shielded inductors in 0.13 μm CMOS

With the increasing interest in 60 GHz applications, low-cost CMOS circuit solutions emerge. The poor performance of CMOS devices at millimeter-wave frequencies complicates the design. In this work, we present two low-area VCOs covering the license-free 60 GHz band, using differential shielded (slow-wave) transmission line inductors. We discuss design and provide compact modeling of these inductors, compatible with stringent metal density rules of scaled CMOS. Measured phase noise below -90 dBc/Hz at 1 MHz offset is achieved, at a consumption of 3.9 mW at 1 V. The tuning range exceeds 10%, for a tuning voltage restricted from ground to the supply.