Picosecond and subpicosecond electrical shock-wave generation on a gallium arsenide nonlinear transmission line

Circuits for the generation of ultrafast step and pulse signals have many applications in time-domain and wide-bandwidth microwave systems. The silicon step-recovery diode (SRD) is widely used in sampling oscilloscopes and network analyzers up to 30 GHz, but has limited utility in millimeter-wave instrumentation or ultrafast optoelectronic applications due to its relatively slow speed (30-40 ps). Capitalizing on the huge speed advantage of the Gallium Arsenide Shottky varactor diode, this thesis describes a number of monolithic integrated circuits that were built based on picosecond shock-wave generation on a periodic Nonlinear Transmission Line (NLTL).; The NLTL is a high impedance transmission line that is periodically loaded with Schottky varactor diodes to produce a synthetic structure on which the small-signal propagation velocity depends on the voltage-variable capacitance of the diodes. The sign of the nonlinearity is such that a small, zero-biased signal propagates more slowly than a small, reverse-biased signal. This effect results in a decrease in the transition time of a large-signal, negative-going, voltage step as it travels down the line. The minimum transition time attainable is determined by the diode nonlinearity and RC cutoff frequency, as well as the limitations imposed by the transmission line structure, and is, in theory, well below 1.0 ps. In practice, output transition times down to 1.6 ps have been measured on a hyperabrupt-doped NLTL circuit using a novel optical technique known as direct electrooptic (EO) sampling. These step signals are the fastest ever generated by all-electronic means.; An NLTL circuit was also used in a simple sampling oscilloscope application and the instrument was found to have at least 130 GHz of bandwidth, over three times what is possible with an SRD. Finally, the step output from an NLTL was filtered to produce a pulse output with a 4.4 ps width and a 2 V amplitude. This performance is comparable to the speed of the superconducting Josephson Junction device but the NLTL operates at room temperature and has an amplitude that is 100-1000 times larger.