Hussain A. Hammas - Academia.edu (original) (raw)
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Papers by Hussain A. Hammas
The design of a fractal based slot antenna, to serve the dual-band communication applications, is... more The design of a fractal based slot antenna, to serve the dual-band communication applications, is proposed in this paper. The structure of the proposed antenna is based on the Koch snowflake fractal geometry of the third iteration as applied to the outer and inner perimeters of an annular ring slot configuration. The antenna slot structure has been etched on one side of a substrate representing its ground plane, and a microstrip line feed is printed on the other side. The realized results proved that the proposed antenna could excite three resonant modes. The first one was assigned for the lower resonating band from (2.24-2.93) GHz, while the second and third modes have been merged forcibly to generate the upper resonating band from (4.48-5.54) GHz. In terms of the guided wavelength, λg, the resulting antenna has a compact size of 0.57λg × 0.57λg. The results reveal that the antenna yields two resonant bands with a significant extent of the frequency ratio. To improve the antenna performance at the two resonant bands, investigation of current density distributed on the surface of the antenna is conducted at selected frequencies within the swept range. With the aid of this study, it has been found that when applying a defected ground structure (DGS) on the antenna ground plane, it can be considered as a tuning means of the two resonant bands. Measured results carried out on two fabricated prototypes confirm those theoretically predicted.
The design of a fractal based slot antenna, to serve the dual-band communication applications, is... more The design of a fractal based slot antenna, to serve the dual-band communication applications, is proposed in this paper. The structure of the proposed antenna is based on the Koch snowflake fractal geometry of the third iteration as applied to the outer and inner perimeters of an annular ring slot configuration. The antenna slot structure has been etched on one side of a substrate representing its ground plane, and a microstrip line feed is printed on the other side. The realized results proved that the proposed antenna could excite three resonant modes. The first one was assigned for the lower resonating band from (2.24-2.93) GHz, while the second and third modes have been merged forcibly to generate the upper resonating band from (4.48-5.54) GHz. In terms of the guided wavelength, λg, the resulting antenna has a compact size of 0.57λg × 0.57λg. The results reveal that the antenna yields two resonant bands with a significant extent of the frequency ratio. To improve the antenna performance at the two resonant bands, investigation of current density distributed on the surface of the antenna is conducted at selected frequencies within the swept range. With the aid of this study, it has been found that when applying a defected ground structure (DGS) on the antenna ground plane, it can be considered as a tuning means of the two resonant bands. Measured results carried out on two fabricated prototypes confirm those theoretically predicted.