Silicon Germanium Heterojunction Bipolar Transistors
Large-Signal Modeling and Low-Frequency
Noise Characterization Aspects.
PhD Thesis, Uppsala University,
Acta Universitatis Upsaliensis 479,
Introduction (126 pages)
in Postscript, 19.2M ;
compressed (gz), 1932K
Papers included in the thesis (58 pages)
in Postscript, 8.2M ;
compressed (gz), 2283K
Paper copies of the thesis can be obtained from
Signals and Systems Group, Uppsala University,
Box 534, SE-75121 Uppsala, Sweden.
entry in list of publications
With the progress in Silicom Germanium
technology, fabrication of high performance
heterojunction bipolar transistors has become fesible
and devices with fmax of 90 GHz in a
common-emitter configuration have been achieved with
repeatability. This opens the possibility of
designing circuits operating in the millimeter-wave
frequency region using such transistors. This thesis
deals with different aspects of the device.
- 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 trans-impedance 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 noise corner frequency are discussed.
SiGe, Heterojunction Bipolar Transistor,
thermal time constant,
Extraction of thermal time constant in HBTs using small
signal measurements.Electronics Letters 1997.
In Postscript :
, uncompressed 334K.
- On the design of a 55 GHz Si/SiGe HBT frequency doubler
operating close to fmax.
Proc. 26th European Microwave Conference, Prague 1996.
In Postscript :
Development, implementation and verification of a physics-based
Si/SiGe HBT model for millimeter-wave
non-linear circuit simulations.
Proc. 26th European Microwave Conference, Prague
In Postscript :
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