Effect of lateral structure parameters of SiGe HBTs on synthesized active inductors**Project supported by the Natural Science Foundation of Beijing, China (Grant Nos. 4142007 and 4122014), the National Natural Science Foundation of China (Grant No. 61574010), and the Higher Educational Science and Technology Program of Shandong Province, China (Grant No. J13LN09).

Abstract

The effect of lateral structure parameters of transistors including emitter width, emitter length, and emitter stripe number on the performance parameters of the active inductor (AI), such as the effective inductance Ls, quality factor Q, and self-resonant frequency ω0 is analyzed based on 0.35-μm SiGe BiCMOS process. The simulation results show that for AI operated under fixed current density JC, the HBT lateral structure parameters have significant effect on Ls but little influence on Q and ω0, and the larger Ls can be realized by the narrow, short emitter stripe and few emitter stripes of SiGe HBTs. On the other hand, for AI with fixed HBT size, smaller JC is beneficial for AI to obtain larger Ls, but with a cost of smaller Q and ω0. In addition, under the fixed collector current IC, the larger the size of HBT is, the larger Ls becomes, but the smaller Q and ω0 become. The obtained results provide a reference for selecting geometry of transistors and operational condition in the design of active inductors.