FD-TD ANALYSIS OF VIVALDI FLARED HORN ANTENNAS AND ARRAYS

This paper summarizes a detailed computational study of Vivaldi flared horn antenna designs including single element, double element, crosse d-pair subarray elements, and linear arrays using the finite-differenc e time-domain (FD-TD) method. FD-TD, which numerically solves Maxwell' s time dependent curl equations, accounts for the complex geometrical and electrical characteristics associated with this antenna design and array implementation. Validations have been made relative to a moment method (MM) model of an electrically large linearly tapered slot ante nna. Also, good correlation is shown to exist in the primary features of the antenna patterns between computed and measured data for all cas es. This work has achieved a number of firsts for the FD-TD methodolog y. It represents the first ''exact'' computational model of a single q uad Vivaldi slot antenna; the first ''exact'' computational model of a phased array of Vivaldi quad elements; and the first FD-TD model to d emonstrate grating lobes for a phased array antenna of any sort. Lastl y, this research represents an extensive study of the largest grid-bas ed antenna models conducted to date.