All-PMOS Wideband VCO with an Automatic Amplitude Controller for Multiband Multistandard Radios

A full PMOS, low phase noise, and wideband VCO with an automatic amplitude controller (AAC) is presented The frequency band and tuning voltage are 2.78-3.78 GHz and 0-1.8 V, respectively. The measured phase noises at 1 MHz from carrier frequencies of 2.83, 3.24, and 3.77 GHz are -126.5, -125.0 and -122.7 dBc/Hz, respectively. With 1.8 V voltage supply, the current flowing into the VCO core varies from 4.9 raA to 5.7 mA. VCOs with/without an AAC were fabricated in TSMC 0.18 mum CMOS technology.