This paper presents a new CMOS LC-VCO with a 2.95–3.65 GHz tuning range.The large tuning range is achieved by tuning curve compensation using a novel varactor configuration,which is mainly composed of four accumulati...This paper presents a new CMOS LC-VCO with a 2.95–3.65 GHz tuning range.The large tuning range is achieved by tuning curve compensation using a novel varactor configuration,which is mainly composed of four accumulation-mode MOS varactors（A-MOS）and two bias voltages.The proposed varactor has the advantages of optimizing quality factor and tuning range simultaneously,linearizing the effective capacitance and thus greatly reducing the amplitude-to-phase modulation（AM-PM）conversion.The circuit is validated by simulations and fabricated in a standard 0.18μm 1P6M CMOS process.Measured phase noise is lower than–91 dBc at 100 kHz offset from a 3.15 GHz carrier while measured tuning range is 21.5%as the control voltage varies from 0 to 1.8 V.The VCO including buffers consumes 2.8 mA current from a 1.8 V supply.展开更多
文摘目的评价感音神经性听力损失患者(耳蜗病变)与听神经病谱系障碍患者听觉系统的频率选择特异性,对比说明不同类型听力损失对听觉系统频率选择特异性的影响。方法使用测量心理物理调谐曲线(psychophysical tuning curve,PTC)的方法评价频率选择特异性,即当存在一个纯音信号,其频率和强度保持不变,加入另一个窄带噪声,噪声的中心频率和强度均发生变化,通过改变噪声的中心频率与强度掩蔽纯音信号,由此获得的窄带噪声中心频率与其强度的关系曲线。PTC越窄,尖部越尖锐说明频率选择特异性越好,使用测试频率与PTC曲线最小强度上10 d B的曲线宽度的比值(Q10dB)评价PTC曲线的尖锐程度。选取听力正常受试者11名,感音神经性听力损失受试者14例,听神经病谱系障碍患者17例,测量3个组受试者双耳在500Hz和1000Hz处的心理物理调谐曲线。结果听力正常受试者平均Q10dB结果为3.4±0.9,感音神经性听力损失受试者平均Q10d B结果为1.8±0.4,听神经病谱系障碍受试者平均Q10d B结果为3.5±1.0。听神经病谱系障碍患者组Q10 d B结果与听力正常组Q10dB结果间无显著性差异(P>0.05),而感音神经性听力损失组Q10dB结果与听力正常组(F=34.90,P<0.001)和听神经病谱系障碍组Q10dB结果间均存在显著性差异(F=31.09,P<0.001)。结论耳蜗病变会导致频率选择特异性障碍,而听神经病谱系障碍患者听觉系统的频率选择特异性可能基本正常。
基金supported by the National High Technology Research and Development Program of China(No.2007AA12Z344)
文摘This paper presents a new CMOS LC-VCO with a 2.95–3.65 GHz tuning range.The large tuning range is achieved by tuning curve compensation using a novel varactor configuration,which is mainly composed of four accumulation-mode MOS varactors（A-MOS）and two bias voltages.The proposed varactor has the advantages of optimizing quality factor and tuning range simultaneously,linearizing the effective capacitance and thus greatly reducing the amplitude-to-phase modulation（AM-PM）conversion.The circuit is validated by simulations and fabricated in a standard 0.18μm 1P6M CMOS process.Measured phase noise is lower than–91 dBc at 100 kHz offset from a 3.15 GHz carrier while measured tuning range is 21.5%as the control voltage varies from 0 to 1.8 V.The VCO including buffers consumes 2.8 mA current from a 1.8 V supply.
