In this project we propose to design an
electrically small antenna system for High Frequency Surface
Wave Radar (HFSWR).Design improvements include the use of
meander line to reduce size while maintaining the desired
resonance frequency, the use of multiple-arm folding to
increase the radiation resistance and the use of reflectors
to further improve the directivity and increase the antenna
gain. Based on the design (Fig. 1a) and the prototyping
(Fig. 1b) of the proposed antenna, it is shown that these
design improvements provided broader band coverage in the HF
bandwidth with acceptable VSWR and increased radiation
resistance without the need for stub-matching networks. The
physical dimensions of the initial design is significantly
smaller (in the longest dimension) than traditional
quarter-wave monopole antennas.
Tasks
:
The antenna is being modeled using FEKO and IE3D.
Fig. 1a depicts the FEKO model of the proposed design
where it may be seen that a two-arm folded antenna is
used to improve the resulting value of the radiation
resistance, and the feed system is placed at the center
of the ground plane instead of at the end of the meander
line. In addition, some emphases will be placed on the
development of multiple operating frequencies in the HF
band.
Development of new prototypes with improved
radiation efficiencies
Continue with laboratory and field testing and
measurement including locations along the coastline
Utilize DSP to facilitate beam steering capability
when an array arrangement is used.
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Fig. 1a. Model of
prototype antenna
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Fig. 1b.
Prototype antenna at test site. |
