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|Title: ||A treatise on power amplifier efficiency : thermodynamics and quantum transport approach|
|Other Titles: ||Re dong li xue ji liang zi chuan dong xue yun yong yu gong lü fang da qi xiao neng fen xi lun shuo|
|Authors: ||Lee, Shu Chuen (李樹泉)|
|Department: ||Department of Electronic Engineering|
|Degree: ||Doctor of Philosophy|
|Issue Date: ||2010|
|Publisher: ||City University of Hong Kong|
|Subjects: ||Power amplifiers.|
|Notes: ||CityU Call Number: TK7871.58.P6 L39 2010|
xi, 134 leaves : ill. 30 cm.
Thesis (Ph.D.)--City University of Hong Kong, 2010.
Includes bibliographical references (leaves 128-134)
|Abstract: ||Physics imposes fundamental constraints on power amplifier (PA)
efficiency. PA is unambiguously thermodynamic system that generates
waste heat. One physical constraint concerns heat dissipation which
limits the size and efficiency of PA. The irreversible heat loss generated
during signal amplification process reduces the efficiency of a PA.
To date, very few methods are available for the design of PAs; many
of the design processes have been empirical. The theoretical work in this
thesis attempts to describe an analytical method for analysing PA's
efficiency using the underlying principles of physics. The analysis starts
from the second law of thermodynamics and the concept of entropy.
Entropy upper bounds of a physical system is determined from the black
hole thermodynamics and Stefan-Boltzmann laws of thermal radiation.
The result helps to formulate an argument to the scaling of electronic
devices. 1) The entropy of a physical system is ultimately bounded in
proportional to its surface area. 2) Device scaling is a proper way to
improve energy conversion efficiency in the sense of reducing heat
dissipation. Quantum mechanics and thermodynamics impose limits on scaling. The limits of scaling from the constraint of heat removal has been
developed. A figure of merit that relates switching speed and minimum
chip area is proposed.
A novel one-dimensional method for the fast computation of the
thermal characteristics of GaAs HBTs PA has been developed. The most
effective form factors of heat removal spreader structure are investigated
Finally, a nanoscale model based on drift-diffusive and quantum
transport approach with non-equilibrium Green's function method, for the
computation of the MOSFET switching loss, is proposed and developed.
The model is valid for MOSFET with channel lengths above the electron
de Broglie wavelength (~10 nm). The study empowers MOSFET
switching loss to be determined from the contact materials'
wavefunctions, channel length, source and drain doping concentration,
DC bias, switching frequency and ambient temperature.|
|Online Catalog Link: ||http://lib.cityu.edu.hk/record=b3947848|
|Appears in Collections:||EE - Doctor of Philosophy |
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