带自适应体偏置的宽带LC VCO自动幅度控制策略

为了优化宽带LC型压控振荡器（LC VCOs）相位噪声性能,提出一种自动幅度控制策略。该策略结合了自适应体偏置和数字校准。当VCO开始工作时,自适应体偏置技术使VCO在不同的工艺角、电压和温度（PVT）情况下快速起振。当谐振频率变化时,在自适应体偏置和数字校准的作用下,VCO的谐振幅度被控制在最优值附近,达到优化相位噪声的目的。在TSMC 0.18μm CMOS工艺中,覆盖频率范围为1.6～3.2GHz的宽带LC VCO用来验证该幅度控制策略的可行性。基于SpectreRF的仿真结果表明LC VCO的幅度变化率降低90%,且在3.2GHz谐振频率,10kHz频率偏移处的相位噪声改善8.2dB。

Adaptive body-bias based automatic amplitude control for wideband LC VCOs

In order to optimize the phase noise of the wideband LC voltage controlled oscillators(LC VCOS),a strategy of automatic amplitude control is proposed.The strategy combines adaptive body-bias technique with digital calibration.When VCO works,the adaptive body-biased technique ensures the VCO oscillating as soon as possible regardless of PVT variations.When oscillation frequency is changed,by using of the adaptive body-biased technique and the digital calibration,amplitude of wideband VCO could be adjusted to the level of optimal value for phase noise optimization.A wideband LC VCO with oscillation frequency ranging from 1.6 GHz to 3.2 GHz is used to verify the feasibility of the proposed strategy,which is implemented in TSMC 0.18 μm CMOS technology.SpectreRF based simulation results show amplitude derivation is reduced by 90%.Besides,phase noise at 3.2 GHz carrier and 10 kHz frequency offset is 8.2 dB better.