Koch fractal-based hexagonal patch antenna for circular polarization


Abstract: The design and performance of an inset feed modified hexagonal patch antenna for possible applications in ultrawideband communication systems is reported. The inset feed hexagonal patch antenna is modified by introducing a fractal up to the second iteration. A right-angled isosceles triangular microstrip antenna is used in the Koch fractal structure on the edges. The proposed antenna is a combination of two standard fractal structures, i.e. Sierpinski and Koch. A rectangular defect in the ground has also been done. The antenna is simulated by applying CST Microwave Studio simulation software. The results are verified by fabricating the antenna and tested using a vector network analyzer. The developed design shows good matching with the feed network at frequencies of 3.1 GHz, 6.9 GHz, 7.3 GHz, 8.5 GHz, and 9.1 GHz. The simulated peak gain of the antenna at resonant frequencies is 4.08 dB, 4.79 dB, 3.85 dB, 3.46 dB, and 3.01 dB. The antenna is fabricated on FR-4 substrate having size 30 $\times $ 35 $\times $ 1.59 mm$^{3}$. It covers the S and X band range. It can be used for microwave applications as it is a part of the microwave spectrum, for wireless networking devices coming under IEEE standards. It can also be used for multimedia applications like mobile TV and satellite radio that use the S band as their frequency range and in home-based consumer electronics like microwave ovens, cordless phones, and wireless headphones. For higher ranges, i.e. in the X band, it can be used in radars, satellites, and military appliances.

Keywords: Microstrip patch antenna, ultrawideband, Koch fractal, defected ground structure, circular polarization

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