Limitations of current compact transit-time models for III–V-based HBTs

This paper investigates the accuracy limitations of common compact bipolar transistor models towards higher frequencies. The device under test is a InGaP/GaAs HBT, simulated by the FBH HBT model. The results, however, analogously hold for similar bipolar devices and models. The investigation is based on an analytical approach that explains how the model approximations impact simulation accuracy. A model extension is proposed that improves the model at higher frequencies. Measurements are compared with large-signal model simulations that prove the analytical reasoning and highlight the relevance of the effect under realistic operation conditions.

[1]  Matthias Rudolph,et al.  Introduction to modeling HBTs , 2006 .

[2]  R. Doerner,et al.  Towards a unified method to implement transit-time effects in Pi-topology HBT compact models , 2002, 2002 IEEE MTT-S International Microwave Symposium Digest (Cat. No.02CH37278).

[3]  M. Rudolph,et al.  New extraction algorithm for GaAs-HBTs with low intrinsic base resistance , 2002, 2002 IEEE MTT-S International Microwave Symposium Digest (Cat. No.02CH37278).

[4]  R. Doerner,et al.  Consistent modeling of capacitances and transit times of GaAs-based HBTs , 2005, IEEE Transactions on Electron Devices.

[5]  James C. M. Hwang,et al.  Implementation of nonquasi-static effects in compact bipolar transistor models , 2003 .

[6]  W. Heinrich,et al.  Low phase noise MMIC VCOs for Ka-band applications with improved GaInP/GaAs-HBT technology , 2003, 25th Annual Technical Digest 2003. IEEE Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 2003..