Date of Award

3-22-2018

Document Type

Thesis

Degree Name

Master of Science in Electrical Engineering

Department

Department of Electrical and Computer Engineering

First Advisor

Andrew J. Terzuoli, PhD.

Abstract

A bandwidth analysis of a tightly-packed crossed-dipole array antenna is presented in this thesis. A parametric study is described which varies the element spacing in the array and the resulting change in the terminal impedances is reported. The increased mutual coupling seen by the elements as a result of smaller element spacings is shown to minimize the variation in the value of the elements terminal currents across a 0.3 GHz to 3.0 GHz frequency range. This small variation in current translates into a minimal variation in the terminal impedances for a fixed excitation voltage. This is shown to be an ideal condition in which to perform a wide-band impedance matching technique using stepped-transmission lines to bring the voltage-standing-wave-ratio (VSWR) of the array below 2. The analysis is performed using a method-of-moments computational electromagnetics code which models the antenna as a finite-by-infinite array using Floquet Mode expansion. The current distribution and the far-field pattern across the L-band frequency range for the array is also presented.

AFIT Designator

AFIT-ENG-MS-18-M-041

DTIC Accession Number

AD1056161

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