Silicon Germanium heterojunction bipolar transistors: Large-signal modeling and low-frequency noise characterization aspects
1999 (English)Doctoral thesis, comprehensive summary (Other academic)
In this thesis, aspects of the Silicon Germanium (SiGe) Heterojunction Bipolar Transistor (HBT) are addressed. A physics-based electrical large-signal model including thermal dependence has been developed and is implemented using a commercially available simulator package. Good agreement-is found between calculated data using the model and measured data. Equations for the electrical parameters based on physical data and a fitting procedure for finding parameter values concerning parasitic effects are presented. In addition, a technique for extracting very short thermal time constants using small signal measurements is presented.
Using the large-signal model, a frequency multiplier employing a single SiGe HBT as the non-linear device has been designed and fabricated. The doubler operates with an output frequency of 55 GHz and performance can be well explained using the model.
Low-frequency noise in the SiGe HBT has been studied, primarily using transimpedance amplifiers. Problems related to the measurement of low-frequency noise are discussed. The dominant noise source in a SiGe HBT is discriminated using direct two-channel noise measurements for a sweep of base resistance terminations of the device. By employing a device temperature variation the temperature dependence of the dominant source is further studied. A method for improved coherence measurements during a sweep of base resistance terminations is presented. A method for modeling low-frequency noise in a SPICE based simulator and aspects of the noisecorner frequency are discussed.
Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis , 1999. , 126 p.
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 479
Materials science, Silicon Germanium, SiGe, Heterojunction Bipolar Transistor, HBT, Large-signal modeling, thermal time constant, low-frequency noise: coherence, transimpedance amplifier
Research subject Electronics
IdentifiersURN: urn:nbn:se:uu:diva-377ISBN: 91-554-4558-6OAI: oai:DiVA.org:uu-377DiVA: diva2:163631
1999-11-12, Room 4001, Ångström laboratory, Uppsala University, Uppsala, 09:30 (English)