对SiGe HBT的高频噪声进行了模拟。频率f、载流子正向延迟时间τF、集电极电流等因素都对高频噪声有影响。当频率高于高频转角频率时,最小噪声系数NFmin随着频率的增大而线性增大,而不是与f2成正比关系,且NFmin随着集电极电流的增大先减小后增大。结果表明,噪声最小时的最佳偏置电流所对应的特征频率fT并不是最大特征频率,约为最大特征频率的50%。 SiGe HBT high-frequency noise was simulated. Frequency f, carrier forward delay time τF, collector current and other factors have an impact on high-frequency noise. When the frequency is higher than the high-frequency corner frequency, the minimum noise figure NFmin linearly increases with the increase of frequency, not proportional to f2, and NFmin decreases first and then increases with the increase of collector current. The results show that the characteristic frequency fT corresponding to the optimum bias current when the noise is minimum is not the maximum eigenfrequency, which is about 50% of the maximum eigenfrequency.