High data rate pulse compression using non-linear transmission line (NLTL) technology

The design methodology of compact MMIC Non-Linear Transmission Lines (NLTLs) using silicon Schottky diodes is considered in this thesis. The application area is in the pulse compression and pulse shortening to minimize the Inter-Symbol Interference (ISI) in electro-optic backplane systems. A Silicon NLTL MMICs based on coplanar wave guide technology have been fabricated as demonstrator.

A novel silicon Schottky diode has been proposed for this work using Silicon-Silicide on Insulator (SSOI) technology. The effect of doping profile on the Schottky diode non-linear CV characteristic is investigated using a physical simulator. Simulation is used to investigate the effect of different doping regimes on NLTL performance. The silicon Schottky diode performance and the doping profile parameters are investigated using the physical device simulator before fabrication. Reliable operation of the silicon Schottky diode and therefore the reliability of the NLTL, is investigated.

The Schottky diode and the NLTL fabricated using four different masks. The fabrication details in this work are presented.

A Schottky diode model has been developed for operation within simulated NLTL designs based on model extraction from standard foundry devices. Small and large signal measurements are used to validate the model over the ranges of frequency, applied bias and RF power level.

A wide bandwidth NLTL has been fabricated using the SSOI technology. A tapered NLTL is simulated using the extracted Schottky diode model. Pulse compression circuit using two NLTLs and power combiner circuit has been fabricated using the SSOI Schottky diode. Measurements of the demonstrator devices have been compared against simulation with good agreement.