A comparison between two 1.8GHz CMOS VCOs tuned by different varactors

In English Two 1.8GHz CMOS VCOs, based on a diode-varicap and an MOS-varicap, respectively, have been designed in a 0.8µm digital CMOS process and tested. Although the tuning range is larger for the MOS-varicap VCO, the overall performance of the diode-varicap VCO is superior to that of the MOS-varicap VCO. The comparison might give a different result by adopting a CMOS process that allows for shorter minimum transistor gate lengths.