1200 MHz fully integrated VCO with "Turbo-charger" technique

Fully integrated VCO with "turbo-charger" technique has been presented. The phase noise degradation of relatively lower oscillation frequency in tuning range has been investigated. It was caused by oscillation amplitude lowering due to large total capacitance. New "turbo charger" technique is operation current increasing to increase trans-conductance of amplifier when control voltage is lower. The phase noise of VCO that was adapted this technique, was presented extremely low and stable, below -140 dBc/Hz at 3 MHz offset from oscillation frequency, in wide oscillation frequency range, approximately 200 MHz for 1200 MHz oscillation with 5.8-7.4 mA current consumption using 0.6 µm Si-Ge BiCMOS process.