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I
am a Ph.D. candidate in the Department
of Electrical and Computer Engineering at university
of Illinois, Urbana-Champaign. I am working in Center
for Computational Electromagnetics and Electromagnetics Laboratory
under Prof.
José E. Schutt-Ainé.
Education:
- Ph.D.,
Electrical Engineering, University of Illinois at Urbana-Champaign,
Fall 2004 - Present.
- M.S.,
Electrical Engineering, University of Illinois at Urbana-Champaign,
Fall 2002 - Summer 2004.
-
B.S., Electrical
and Computer Engineering , Addis
Ababa University, Ethiopia, Fall 1995 - Spring 2000.
Research
Area:
- Passive
Maromodel Generation of High-Speed Interconnects and Packages
As
operating frequencies increase and device sizes decrease,
the complexity of modern circuits are putting enormous pressure
on computer aided design tools. In the VLSI area, interconnect
effects such as signal delay, cross-talk, ringing, reflections
and distortion can severely affect the signal integrity
of the designs. Consequently, circuit designers must consider
interconnect analysis to ensure circuit performance and
reliability. The main purpose of this work is to approximate
a frequency dependent date either from measurement or from
full wave analysis of an element or a structure. Using the
vector fitting method, an analytical equation which governs
the system behavior with a wide range of dynamic frequency
achieved using simple first order differential equation.
The vector fitting method depends on the selection of good
starting pole for the approximation and the accuracy also
depends on this initial poles. To alleviate this problem,
a rational interpolation method is used prior to using the
vector fitting method. The interpolation method gives a
better initial guess to the vector fitting method. Using
the combination of the two methods, an accurate, a stable
and a robust methodology is achieved. This combined method
does not depend on the type of the approximation date. The
method works for S, Y, Z or any parameter data, which is
independent of parameter type. This allows flexibility to
the user. One of the major achievements of this combined
method is its convergence. No matter what the type of data
is, the method always reaches its optimal solution. The
method is a least square approximation technique based on
pole-zero relocation technique. The method does not suffer
from numerical problem when approximating high-order system
over a wide frequency range. The physical behavior of the
interconnect such as stability, causality and passivity
of the macromodel is also preserved. In addition, the algorithm
can be used to perform statistical analysis of interconnect.
- Statistical
analysis of on-chip interconnects
As
technology scales, understanding semiconductor manufacturing
variation becomes essential to effectively design high performance
circuits. Process variation is a key concern for manufacturability,
process control, and circuit design. Knowledge of process
variation is important to optimize critical path delay,
minimize clock skew, and reduce crosstalk noise. If process
variation is not well understood, unnecessarily large design
margins must be put in place to ensure that desired circuit
performance specifications are met. In this project, the
dual damascene BEOL process is used to analyze and quantify
the impact of process tolerances related to the deposition,
etching, polishing, and other manufacturing operations on
the variability of capacitance of the on-chip wire.
Research
Interest:
Advisor :
Prof. José E Schutt-Ainé
- Signal
integrity analysis of high-speed interconnects and package.
- Efficient
circuit simulation techniques and model order reduction
methods.
- High-Speed
digital and RFIC circuit design, simulation and verification.
- Statistical
analysis of interconnects.
- Digital
Signal Processing
Publications:
- Y.S.
Mekonnen,
J.E. Schutt-Aine, Jilin Tan, C. Kumar, Dragoslav Milosevic,
"Combining Rational Interpolation with the vector-fitting
method," Proceedings of IEEE 14th Topical Meeting
on Electrical Performance of Electrical Packaging, pp 51-54,
Oct 24-26,2005.
-
R. Gao, Y. S. Mekonnen, W. T. Beyene and J. E. Schutt-Aine,
"Black-Box Modeling of Passive systems by Rational
Function Approximation," IEEE Transaction on Advanced
Packaging, Vol. 28,Issue 2, pp 209-215, May 2005.
- Y.
S. Mekonnen, W. T. Beyene and J. E. Schutt-Aine, "Improved
High-Order Approximation by Combining Rational Interpolation
with the Vector Fitting method," 20th Annual Review
of Progress in Applied Computational Electromagnetic, Syracuse,
NY, April 19-23,2004.
- R.Gao,
Y.S.Mekonnen, W.T.Beyene and J.E.Schutt-Aine, "Black-Box
Modeling by Rational Function Approximation," Proceedings
of 8th IEEE Workshop on Signal Propagation oin Interconnects,Heidelberg,Germany,
May 9-12,2004.
Patent:
- Abe
Elfadel, Y.S. Mekonnen, M.S. Angyal, Alina Deutsch,
"Computer-Aided Method and Tool for the Statistical
Analysis of Interconnect Using Manufacturing Process Data,"
Disclosure No YOR820060647, August 2006.(Filed by IBM).
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