A virtual cathode oscillator （VCO） with a resonant cavity is presented and investigated numerically and theoretically, and its efficiency and stability are enhanced. An equivalent circuit method is introduced to ana...A virtual cathode oscillator （VCO） with a resonant cavity is presented and investigated numerically and theoretically, and its efficiency and stability are enhanced. An equivalent circuit method is introduced to analyze the resonant cavity com- posed of anode foil and feedback annulus, and a theoretical expression for the fundamental mode frequency of the resonant cavity is given. The VCO is investigated in detail with a particle-in-cell method. We obtain the microwave frequencies from simulation, theoretical expression, and relative references, and draw three important conclusions. First, the microwave fre- quency is a constant when the diode voltage is changed from 588 kV to 717 kV. Second, the fluctuation of the microwave frequency is very small when the AK gap is changed from 1.2 cm to 1.6 cm. Third, the microwave frequency agrees with the theoretical result. The relative error, which is calculated according to the theoretical and simulation frequencies, is only 1.7%.展开更多
建立了差分互补型电感电容压控振荡器(LC-VCO)的等效分析模型。采用有效截止频率fT,eff来表征MOS管的充放电能力,结合振荡器起振后共模输出电压下降的现象,提出了优化1/f3相位噪声的方法。采用该方法并结合跨导效率gm/ID设计方法,实现了...建立了差分互补型电感电容压控振荡器(LC-VCO)的等效分析模型。采用有效截止频率fT,eff来表征MOS管的充放电能力,结合振荡器起振后共模输出电压下降的现象,提出了优化1/f3相位噪声的方法。采用该方法并结合跨导效率gm/ID设计方法,实现了LC-VCO 1/f3相位噪声的优化,并在0.18μm CMOS工艺上获得验证。结果表明,该优化方法可以使频偏在1 k Hz以内的相位噪声改善2~3 d B,可用于开环LC-VCO作为本振的低功耗无线收发机及高性能晶体振荡器的电路设计中。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11075210)the Postdoctoral Science Foundation of China(GrantNo.201104761)
文摘A virtual cathode oscillator （VCO） with a resonant cavity is presented and investigated numerically and theoretically, and its efficiency and stability are enhanced. An equivalent circuit method is introduced to analyze the resonant cavity com- posed of anode foil and feedback annulus, and a theoretical expression for the fundamental mode frequency of the resonant cavity is given. The VCO is investigated in detail with a particle-in-cell method. We obtain the microwave frequencies from simulation, theoretical expression, and relative references, and draw three important conclusions. First, the microwave fre- quency is a constant when the diode voltage is changed from 588 kV to 717 kV. Second, the fluctuation of the microwave frequency is very small when the AK gap is changed from 1.2 cm to 1.6 cm. Third, the microwave frequency agrees with the theoretical result. The relative error, which is calculated according to the theoretical and simulation frequencies, is only 1.7%.
文摘建立了差分互补型电感电容压控振荡器(LC-VCO)的等效分析模型。采用有效截止频率fT,eff来表征MOS管的充放电能力,结合振荡器起振后共模输出电压下降的现象,提出了优化1/f3相位噪声的方法。采用该方法并结合跨导效率gm/ID设计方法,实现了LC-VCO 1/f3相位噪声的优化,并在0.18μm CMOS工艺上获得验证。结果表明,该优化方法可以使频偏在1 k Hz以内的相位噪声改善2~3 d B,可用于开环LC-VCO作为本振的低功耗无线收发机及高性能晶体振荡器的电路设计中。
