Date of Award


Document Type


Degree Name

Master of Science


Department of Electrical and Computer Engineering

First Advisor

Peter J. Collins, PhD.


The design of a small ultra-high frequency (UHF) antenna for an ultra-wideband (UWB) random noise radar (RNR) system was undertaken to improve system bandwidth and reduce overall system size. The Vivaldi dipole antenna class showed the greatest potential for high performance in this specific application. After extensive computer simulation, three designs were built using two printed circuit board antenna construction methods. The antipodal chopped Vivaldi dipole antenna, built with a milling machine, achieved a wider bandwidth and more uniform spectral performance characteristics. Though current results show improvement over the current log-periodic antenna (LPA) used on the system, greater performance could possibly be achieved with higher fidelity construction methods. The chopped Vivaldi dipole antenna can be classified as a highly efficient, electrically small antenna optimized for UWB applications, due to the combination of small size as well as a nearly uniform frequency response and low dispersion in the UHF bandwidth. Though designed for AFIT's Noise Network (NoNET) system, a UHF UWB RNR, the antenna could be applied to a variety of UHF systems looking to optimize the trade-off between size and power budgets.

AFIT Designator


DTIC Accession Number