Abstract:
The use of micro-strip patch antenna is very common in the Öeld of modern communication for conformal applications with broad beam radiation characteristics. The performance of rectangular patch antenna embedded in dielectric coated surfaces signiÖcantly
degrades due to the excitation of surface waves in dielectric coating and this is analyzed
for various values of dielectric coating thicknesses (6 12mm). The thick layer of dielectric coating causes an increase in return loss and narrow -3dB beam width ( 38
)
in E-plane without signiÖcant change in H-plane radiation pattern of the patch antenna.
For the last few years there has been a growing interest for utilizing the electromagnetic
band-gap (EBG) artiÖcial surfaces to improve the antenna parameters. The degraded
antenna parameters are restored by implementing the artiÖcial surfaces in the form of
conducting metal strips loaded over thick layer of dielectric coating of thickness 12mm.
The issue of composite radome matching is solved by implementing the frequency
selective surface (FSS) over radome. Di§erent planar artiÖcial structures are implemented
surrounding the antenna aperture to restore the broad coverage of patch antenna with
low return loss. The implementation of the artiÖcially hard boundary in the form of
longitudinal metallic strips restores the -3dB beam width ( 102
) of the antenna in Eplane at the cost of antenna gain. Finally the soft ring over dielectric coating surrounding
the antenna aperture is optimized here for broad beam width ( 100
) in E-plane with
increased gain near to 7dB by suppressing the creeped RF energy from thick dielectric
coating.
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