Research Interests and Projects
General Research Interests
- Ultrasound driving circuits.
- Integrated circuits: analog, RF and mixed-signal circuits.
- Circuit modelling and simulation: algorithms for steady-state,
transient analysis and oscillator analysis, electrical-thermal
simulation, transient analysis of frequency-defined components,
nonlinear models, overall circuit simulator architecture.
- Algorithms and object oriented techniques applied to scientific
Research Projects Currently in Progress
Ultrasound Transducer Driving Circuits
This project involves the design of a compact driving system for
ultrasound transducer arrays for medical applications. As a part of
this project, we have developed two integrated prototypes and a new
array driving technique. Details can be found in
the Publications page.
Algorithms for circuit modeling and analysis
The objective of this project is to develop and test new algorithms
for transient and steady-state analysis of electronic circuits.
Research Tools Projects
Cardoon is my latest circuit simulator program under development. The
simulator is written in Python. The design is inspired from the ideas
that worked well in fREEDA and carrot (see below), plus some
improvements that take advantage of the flexibility in Python.
The main goal of this project is to obtain a program which is easy to
modify and test to experiment new simulation algorithms/models. A
secondary objective is to make the program efficient enough to be
useful for general use.
More information about this project can be found
at Cardoon Home
I have participated in the development of the fREEDA(TM) circuit
simulator. Related publications can be found on
my Publications page.
A wave-based State-Variable Transient Analysis has been implemented.
A patch for fREEDA 1.4 to add the wave transient analysis (type:
.wavetran) functionality, in addition to general bug fixes and
convolution support for the Nport device can be downloaded below. The
patched tree was succesfully compiled on Debian squeeze and Ubuntu
(Lucid Lynx) and should compile with any new Linux distribution (gcc
4.4). The original fREEDA 1.4 source code is also provided below.
The patch can be applied as follows (assuming both files are
downloaded in the current directory):
tar xvfz freeda-1.4.tar.gz
zcat ../freeda-1.4w.patch.gz | patch -p1
Carrot circuit simulator
A circuit simulator engine named Carrot. The program is written
in C++. The main design concept is that all device models are
represented by voltage-controlled current sources (VCCS), but instead
of using a unique VCCS class, there are specializations for linear,
nonlinear, independent, etc. Currently the simulator supports DC,
transient with fixed/variable time step and envelope-following
harmonic balance based on the MPDE method.
This paper describes some
design aspects, especially the calculation of sensitivities using
automatic differentiation. Also available
slides. Another set of presentation slides related to
electro-thermal envelope-following simulation in Carrot is
provided here: CMC Texpo 2006 Slides.
Currently this simulator is no longer under active development, but it
is provided here for reference. The source code for carrot is
available under the GPL and can be downloaded here:
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Last Updated: 12/2018