Standing-wave transmission-line-resonator VCO for E-band Applications

In this paper, a fully integrated 42-GHz VCO in 90 nm CMOS is described. This VCO is designed for use in licensed E-band (i.e., 81-86 GHz) transceiver systems. In contrast to conventional LC-VCO topologies, a standing wave transmission line resonator instead of a lumped LC tank is employed to provide an extended output frequency range and relatively low phase noise. A slow wave coplanar waveguide (CPW) structure was used as the transmission line to reduce conductor and radiation losses and to minimize substrate attenuation. Both simulation and chip measurements show good VCO performance. Wide tuning range (1.7-GHz) and low phase noise (-102-dBc/Hz at 1MHz) were achieved. The paper also discusses design criteria and testing strategies.