New high performance and wide range tunable two-stage 3GHz CMOS RF hetero-linked oscillators

New CMOS High performance and wide range tunable two-stage oscillators applicable to the places requiring in- and quadrature-phase components such as RF and data retiming applications are presented. We present two-stage CMOS ring oscillators using phase-look-ahead technique and two kinds of hetero-linked oscillators, the LCRO and the LCXRO. Two-stage ring oscillator is fabricated using 0.8-µm CMOS technology. The maximum oscillation frequency is 914-MHz at 2-V supply. Its phase noise is -87-dBc/Hz at 600-kHz offset. The LCRO and the LCXRO show maximum oscillation frequency of 2.85-GHz and 3-GHz with 3-V power supply. The measured tuning range of the LCRO and the LCXRO are 500-MHz and 100-MHz, respectively, without varactor diodes. Their phase noises are -109- dBc/Hz and -97-dBc/Hz at 600-kHz offset.