Research

1. Acoustic and audio signal processing

   I am interested in reverberation: how can artificial reverberation be made faster and more controlable? What changes are necessary in analytic techniques to accomodate signals in reverberant conditions (all rooms!) Reverberation is problematic in closed fields such a rooms and by distributing the microphones at different places in the modal distribution, it may be possible to achieve higher SNR. I am also interested in modeling the sound (without meshing) of non-linear sources like cymbals and gongs. How can such source be modeled without resorting to full physical modeling? Finally, I am interested in the design of headphones. What changes can and should be made to the physical design to acheive specific psychoacoustic objectives?

2. Electroacoustic Musical Instruments

   How can electroacoustic transducers (e.g. speaker drivers) be used together acoustic mechanisms to create new and expressive musical instruments? How can small electret microphones be used to best effect?

3. Computer System Design

   A modern computer system is a blend of hardware, firmware and software. I have been involved from bottom to top: from transistor level chip design to the implementation of functional languages.

4. Computer Languages in Computer Aided Design

   Current languages, like VHDL (or Verilog) leave much to be desired for the analog world, in spite of recent changes. This is particularly evident when looking at microwave systems, where mixed-signal multi-domain multiport components are the norm. Further research is needed on how to specify microwave systems and how to integrate them with existing tools.

   Increasing processor speeds have enabled DSP to be applied to the radio signal processing environment. Future ultrawideband systems and other formats depends on complex system design and tradeoffs. Accordingly, I am interested in how CAD systems can help evaluate and then design these systems. I am specificially interested in how computer languages can be designed (and implemented) to assist

   • electronic and microwave system design
   • mixed domain signal processing systems
5. RF and Microwave system design

   With the increased interest in the millimeter wave region of the spectrum, additional emphasis must be placed on the design and implementation of measurement tools. As processor speeds have increased, so has the use of DSP at higher sampling rates. How can we trade sampling rate for more complex algorithms? This has profound effects in the implementation of microwave systems. I am interested in two related aspects of RF and microwave design:

   • Exploring digital radio system design tradeoffs for software radio, especially trading sampling rate for algorithmic complexity
   • Instrumentation design and techniques for RF and Microwave measurement -- including circuitry for measurement systems using sampling (high speed sample and holds and low jitter time bases).