Comparison of hybrid pi and Tee HBT circuit topologies and their relationship to large signal modeling

Analytical study of substrate parasitic effects in common-base and common-emitter SiGe BHT amplifiers

“…Hence, in order to study the effect of substrate parasitics on the maximum oscillating frequency (f max ) of the SiGe HBT the variation of the calculated Mason's unilateral power gain (U) with frequency, calculated using eqn. (10), is plotted in Fig. 13.…”

“…Whereas the hybrid-∏ model is the modified version of well-known Gummel-Poon model. Teeter et al [10] has compared both the circuit topologies of SiGe HBTs up to 100GHz. He has shown the direct correspondence between these two models.…”

“…As the frequency of operation increases, the influence of parasitic substrate effects becomes more important and must be taken into account for accurate designing of HBT amplifiers. Several authors have attempted to modify the small-signal equivalent circuit of HBT by including the substrate effects and have proposed direct parameter extraction techniques from a large set of measured S-parameters for SiGe HBT biased in forward active, cut-off and saturation regions [6], [7]- [10]. Huang et al [7] have experimentally studied the influence of substrate parasitic effects on power gains of SiGe HBT in both CB and CE configurations.…”

A comparison of low-frequency noise characteristics and noise sources in NPN and PNP InP-based heterojunction bipolar transistors

“…The Pi-and the Tee-model can be converted mutually by well-known equations. Although the Tee-model is a better physical representation than the Pi-model at high frequencies [14], they are basically identical at low frequencies. By converting van der Ziel's model, one can obtain the Tee-model in Fig.…”

A nonquasi-static table-based small-signal model of heterojunction bipolar transistor

“…T HE GUMMEL-POON large signal model, which is known as quasi-static, has been extensively used by most HBT circuit designers [1] and reduces to a T-model under small-signal conditions [2], [3]. The large signal models have been modified to take many effects into account such as thermal and nonquasi-static effects.…”