Physics based modeling of non-quasi-static effects in SiGe-HBTs

A physics based model for the non-quasi-static (NQS) effects occurring in heterojunction bipolar transistors (HBTs) is presented. Following classical transistor theory, partitioned charge based (PCB) approach is extended to additionally model small-signal frequency-dependent (trans-) conductances. A new large-signal model is implemented in Verilog-A, and is tested for small-signal behavior. Results are compared with numerical device simulation, and its improvement is checked against the results obtained from PCB approach and widely used 2nd order LCR sub-circuit. ©2009 IEEE.