A 3–10 GHz flexible CMOS LO generator for MB-OFDM UWB application using wide tunable VCOs

A frequency synthesizer for MB-OFDM UWB system is implemented in CMOS RF process. The LO generator includes three wide tunable VCOs, PLLs, and quadrature generators. This synthesizer with three VCOs gives more flexible power management scheme and generates lower spurious tones than single side-band mixing method. This scheme supports all band groups except band group 2 which wireless LAN application occupies. Local oscillator including PLLs consumes 17.8 ~ 45.7 mA according to TFC code from 1.2 V power supply. Phase noise has been measured less than -100 dBc/Hz over the operating frequency range.