SiGe HBT射频噪声模型研究

Study on RF Noise Model for SiGe HBT

对现代的双极型晶体管而言,载流子在基极和集电极的空间电荷区(CB SCR)传输延迟可比基极渡越时间,甚至要大于后者。为了更精确地表征了SiGe HBT的射频噪声性能,对van Vliet模型做了扩展,使其包含基极集电极空间电荷区的延迟效应。用2个与噪声相关的延迟时间对transport模型进行了扩展,使得在没有非准静态Y参数的情况下仍然可以对基极和集电极电流噪声进行精确建模。最后,在JC=12.2 mA/μm2,AE=0.12×18μm2条件下,分别对2种模型的基极和集电极噪声电流谱及其归一化相关系数做图并与计算得出的解析值相比较,验证了模型的有效性。

For modern transistors,the transport delay in CB SCR is comparable to or even larger than the base transit time.The van Vliet model is extended to include base-collector space charge region delay so that it can express the RF noise performance of SiGe HBT more exactly.The transport noise model is extended by using two noise-related delay times,so that noise can be accurately modeled in lack of NQS Y-parameters.Finally,the models are proved valid by depicting the two models＇ curves of base and collector noise current spectrums as well as their normalized correlation and by comparing them with the analytical result on the condition of JC= 12.2 mA/ m2,AE=0.12×18 m2.