Research Interests and Projects

General Research Interests

Research Projects Currently in Progress

Integrated Driver for Ultrasonic Transducer

This project involves the design of an integrated CMOS driver for ultrasonic transducer arrays used for medical therapy. A prototype has been fabricated and is being tested. Link to related publication

Ultra-Low-Power CMOS Voltage References

The objective of this project is to design and test an ultra-low power CMOS voltage references. Circuit topologies and a design methodology for power/area optimization will be developed as a part of this project. Link to related publication

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 Circuit Simulator

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 Page

fREEDA Simulator

I heve been participating in the development of the fREEDA(TM) circuit simulator. Related publications can be found at the fREEDA website and on my Publications page.
A wave-based State-Variable Transient Analysis has been implemented recently in Freeda. 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
cd freeda-1.4
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 are presentation 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: carrot-0.3.4.tar.gz

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Last Updated: 07/2014