Broadband 40 GHz Si/SiGe HBT equivalent circuit using a successive analytical model parameter extraction

This paper presents a successive analytical HBT parameter extraction method for the broadband modelling of Si/SiGe HBTs with a unity current gain frequency fT = 54 GHz developed at the Daimler Benz Research Center [4]. Earlier published analytical HBT extraction methods are valid for the device under investigation only in a lower frequency range up to 2 GHz and result in an unphysical negative collector resistance [1], moreover a fully analytical solution was not achieved [1,2,3]. In our general extraction approach we demonstrate for the first time that within the commonly discussed lower frequency range, a fully analytical method can be obtained for the determination of all 12 elements of a basic HBT model with T-topology, making the extraction fast and reliable.