Date of Award

12-1990

Document Type

Thesis

Degree Name

Master of Science in Electrical Engineering

Department

Department of Electrical and Computer Engineering

First Advisor

Vittal P. Pyati, PhD

Abstract

This study investigated the application of a high-frequency model (Uniform Geometrical Theory of Diffraction) of electromagnetic sources mounted on a curved surface of a complex structure. In particular, the purpose of the study was to determine if the model could be used to predict the radiation patterns of cavity-backed spiral antennas mounted on aircraft fuselages so that the optimum locations for the antennas could be chosen during the aircraft design phase. A review of literature revealed a good deal of work in modeling communications, navigation, identification antennas (blade monopoles and aperture slots) mounted on a wide variety of aircraft fuselages and successful validation against quarter-scale model measurements. This study developed a monopole-array model of a spiral antenna's radiation at vertical polarization and an ellipsoid-plate model of the FB-111A. Using the antenna and aircraft models, the existing Uniform Geometrical Theory of Diffraction model generated radiation patterns which agreed favorably with full-scale measured data. The study includes plots of predicted and measured radiation patterns from 2.5 to 15 Gigahertz.

AFIT Designator

AFIT-GE-ENG-90D-10

DTIC Accession Number

ADA230501

Comments

The author's Vita page is omitted

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