A Reconfigurable Picosecond Pulse Generator in Non-linear Transmission Line for Impulse Radar Ultrawideband Applications

Abstract

This letter presents a reconfigurable picosecond (ps) pulse generator (PG) having Gaussian and monocycle pulse shapes for impulse radar ultrawideband (IR-UWB) applications. A mixed step recovery diode (SRD) topology is used in combination with a non-linear transmission line (NLTL) and pulse-shaping circuit to realize the PG. The pulse-shaping network comprises an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RC</i> differentiator embedded with a single p-i-n diode to provide two different switchable states. This PG is capable of directly switching from a Gaussian to a monocycle pulse without resorting to the increase in pulsewidth twice of the original Gaussian pulse as deployed in the previous reconfigurable PGs. The PG based on the proposed technique has a pulse duration of almost 70 ps with a promising ringing level in both cases (Gaussian and monocycle). Moreover, not only is the implementation of this technique easy, but it can also modify the pulse into other important shapes, such as the doublet and higher order Gaussian pulses. The proposed reconfigurable PG is measured in both cases, and the results are presented in each case.