scholarly journals Power and temperature dependence of low frequency noise in AlGaN∕GaN transmission line model structures

2004 ◽  
Vol 96 (10) ◽  
pp. 5625-5630 ◽  
Author(s):  
S. A. Vitusevich ◽  
S. V. Danylyuk ◽  
N. Klein ◽  
M. V. Petrychuk ◽  
A. E. Belyaev
Keyword(s):  
Transmission Line ◽  
Temperature Dependence ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Transmission Line Model ◽  
Line Model ◽  
Model Structures

H 2-Optimal Low Order Transmission Line Models

2019 ◽  
Author(s):  
Bernhard Manhartsgruber
Keyword(s):  
Power Systems ◽  
Transmission Line ◽  
Code Generation ◽  
Transfer Functions ◽  
Linear Time ◽  
State Space Model ◽  
Low Frequency ◽  
Transmission Line Model ◽  
Line Model ◽  
Low Order

Abstract Transmission line modeling has played a crucial role in understanding the dynamics of fluid power systems. A vast body of literature exists from simple lumped parameter approaches to fully coupled three-dimensional fluid structure interaction models. When it comes to computationally efficient, yet physically sound low order models needed for fast computations iteratively called by optimization codes or for the purpose of model based control design, there is still room for improvement. Modal approximations of the input-output behaviour of liquid transmission lines have been around for decades. The basic idea of tuning the parameters of a canonical linear time invariant state space model to fit the transfer functions of a transmission line model in the H2-optimal sense under passivity constraints has been published by the author of the present paper in the past. However, the method so far was barely usable due to numerical difficulties in the underlying optimization process. A new implementation of the method employing quadruple-precision floating point numbers has recently been found to resolve the convergence problems and is reported in the present paper. The new version of the method is based on analytic computation of the cost and constraint functions as well as their gradients in the computer algebra package Maple and automatic code generation for compilation in FORTRAN. Results are very promising because both the entire low frequency behaviour and the first three eigenmodes of a transmission line model can be accurately covered by a model of order eight only.

1/f NOISES OF HOMOPOLAR AND HETEROPOLAR SEMICONDUCTORS

2000 ◽  
Vol 14 (07) ◽  
pp. 751-760 ◽  
Author(s):  
F. V. GASPARYAN ◽  
S. V. MELKONYAN ◽  
V. M. AROUTIOUNYAN ◽  
H. V. ASRIYAN
Keyword(s):  
Experimental Data ◽  
Spectral Density ◽  
Temperature Dependence ◽  
Conduction Electron ◽  
Optical Phonon ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Noise Spectral Density ◽  
Analytical Expressions

The low-frequency noise spectral density with the 1/f spectrum for homopolar and heteropolar semi-conductors is theoretically obtained taking into account conduction electron–optical phonon interactions. The analytical expressions of the spectral density and Hooge's α H parameter are presented. The analytical temperature dependence of Hooge's parameter is compared with experimental data for n-Si and n-GaAs.

Temperature Chaos and the Lattice Character of the Hooge Parameter in Semiconductors

1998 ◽  
Vol 12 (29n30) ◽  
pp. 1245-1254 ◽  
Author(s):  
S. V. Melkonyan ◽  
F. V. Gasparyan ◽  
V. M. Aroutiouyan ◽  
H. V. Asriyan
Keyword(s):  
Temperature Dependence ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Phonon Interaction ◽  
Scattering Mechanisms ◽  
Electron Phonon Interaction

The influence of the electron–phonon interaction on formation of the low-frequency noise in semiconductors is theoretically considered. The determining role of scattering mechanisms in formation of the 1/f low frequency noise is shown. The temperature dependence of the Hooge parameter αH is revealed and explained. The lattice character of αH is proven.

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