A pure analytic method for direct extraction of collector-up HBT's small-signal parameters

Hsien Cheng Tseng, Jung Hua Chou

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


A pure analytic procedure for direct extraction of the small-signal equivalent-circuit parameters, including extrinsic inductances, has been demonstrated and successfully applied to III-V and SiGe collector-up heterojunction bipolar transistors (HBTs). This method can alleviate some difficulties encountered among conventional extracting techniques that are the use of additional test structures, forward-biased measurements at specific bias conditions, and empirical optimization process. In this paper, the hybrid-π equivalent-circuit elements are extracted in a simple and efficient way from impedance and admittance formulation on the basis of measured S-parameters. To study the bias dependence, the extrinsic and intrinsic circuit components are evaluated under different bias conditions. The model parameters are sequentially derived during the extraction process yielding a full set of physical element values. The validity of our model is explored on pnp collector-up AlGaAs-InGaAs HBTs, and a good coincidence between measured and modeled S-parameters is observed for the entire frequency range of operation. Consistent extracted trends indicate that this improved equivalent-circuit model is suitable to be implemented in circuit simulators for microwave-circuit TCAD applications.

Original languageEnglish
Pages (from-to)1972-1977
Number of pages6
JournalIEEE Transactions on Electron Devices
Issue number12
Publication statusPublished - 2004 Dec 1

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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