Design of wideband LC VCO with small Kvco fluctuation for RFID synthesizer application

In this paper, a wideband LC VCO with small Kvco fluctuation for RFID synthesizer application is designed using SMIC 0.18 mum standard CMOS process. The switched capacitor array and switched varactor array are used for wideband design. The VCO exhibited Kvco fluctuation of only 29%, which is about one third that of a conventional VCO. The simulation results show that the tuning frequency range is 64% from 0.76 GHz to 1.48 GHz, VCO Gain is from 41 MHz to 62 MHz with power consumption of about 9 mW at 1.8 V supply. The measured phase noise is less than -90 dBc/Hz at 100 kHz offset within the entire tuning range.