Design of survivable shipboard HF mast antenna models using the numerical electromagnetics code
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Authors
Choi, Il Yong
Subjects
survivable shipboard HF mast
antenna models
antenna models
Advisors
Adler, Richard W.
Date of Issue
1987
Date
Publisher
Monterey, California: U.S. Naval Postgraduate School
Language
en_US
Abstract
Modern combat ships are crucially dependent on electromagnetic systems
including numerous and varied types of antennas. There are many shipboard
communication antenna parameters such as location, number, type, and survivability
of given antenna systems. Each of these parameters can be varied to determine the
overall optimal system. This thesis investigates computer numerical models to improve
combat survivability for HF shipboard antenna systems. Future generations of ships
will have low profile combat survivable antennas. Possible improvements for present
ships might be the elimination of fragile HF antennas by exciting existing mast
structures. Two mast configurations resembling an FFG-45 class ship are investigated
for various heights: (1) a simplified rectangular column representing a forward mast,
and (2) a tapered column containing more details and closely resembling an after mast.
The masts are modeled by using surface patches and wire grids. Six computer models
of the given masts are developed by the Numerical Electromagnetics Code (NEC).
Average power gain, input impedance, and radiation patterns of driven antennas are
presented and the results between surface patch models and wire grid models are
compared for frequencies from 2 MHz through 16 MHz. It is seen that good
performance is possible, for several different feed methods, when using existing mast
structures for 2-16 MHz. Some feeding techniques and NEC modeling options that
were tried were unsuccessful and yielded non-physical results.
Type
Thesis
Description
Series/Report No
Department
Electrical and Computer Engineering
Organization
Identifiers
NPS Report Number
Sponsors
Funder
Format
132 p.: ill. 28 cm.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
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Copyright is reserved by the copyright owner.