This research encompasses three major fronts:

• On-chip integrated high speed wires and repeater circuits. We are investigating integrated geometrical structures like differential microstrip transmission lines to improve electrical digital signal propagation across large VLSI chips.  Special non-linear VLSI repeater circuits are also being developed to provide negative capacitance to propagating signals.  Theoretical analysis will be compared to actual Maxwell equation simulations to derive simplified design models.  Accurate electrical modeling is performed using a FDTD simulator from Cray Research called.  A simple simulation of an electrical Gaussian pulse propagating down a single-ended Aluminum microstrip transmission line over a ground plane is shown below as an animated GIF.  The image color represents the power in the signal: blue corresponds to minimum power, red is the maximum power.  A resistive load of 50 Ohms (half the characteristic line impedance) is placed in the center of the guide from the line to ground to model an impedance discontinuity.  As time progresses, you will first see the incident wave emerge from the voltage source on the left end of the line, then the wave will encounter the load and a negative voltage, back-propagating (reflected) wave (30% of the voltage) will be generated due to the impedance mismatch.  The transmitted wave with diminished (70% voltage) will continue down the line to right, as the energy radiates off the end of the line.

 

• Off-chip capacitively-coupled electrical or optoelectronic links utilizing differential receiver and transmitter arrays.

• High-speed, low power, low skew electrical clock distribution using resonant transmission line techniques and MCM integration.