Generating RF pulses using a nonlinear hybrid line

Abstract

A nonlinear lumped element transmission line (NLETL) that comprises a LC-ladder network where either the capacitors or inductors are nonlinear can be used to convert an input rectangular pulse to a series of RF pulses at the output. This article describes the implementation and demonstration of a high voltage nonlinear hybrid line (NLHL) where both the line components (inductor and capacitors) are nonlinear. Lines with only one nonlinear component have numerous publications in simulation and experimentations whereas NLHL has only a few articles in simulation. There is no report about NLHL being tested to-date according to our knowledge. We have built and tested a NLHL using commercial-off-the-shelf (COTS) components. Instead of using complex pulse forming networks or pulse forming lines, a storage capacitor and a fast semiconductor switch are used to provide an input pulse with good approximation of a rectangular pulse-shape. Experiment results are compared with simulations predicted by the in-house developed NLETL circuit model. Analyses on the voltage modulation and frequency content of the output pulses are carried out. The conditions for producing RF pulses in NLHL and its performance are discussed.