Dual-band aperture coupled antenna with harmonic suppression capability

According to the findings by [18], the antenna overall physical size is reduced using the fractal design and with the introductory of H-shaped defected ground structure (DGS) to suppress the harmonics created from the fractal iteration, thus the complexity of the antenna geometry increased. Based upon authors literature review and knowledge findings, the study by previous researchers focused more on either single-band frequency characteristic or, multi-band frequency of that 0.9 GHz and 2.45 GHz and very small amount of study which involved multiband frequency response of that WLAN frequency spectrum. The proposed embedded U-slot at the feed line is observed to suppress the reflection coefficient at frequency 5.00 GHz, initially from -21.143 dB to -14.537 dB however with the proposed design, the fourth harmonic is being introduced at 9.45 GHz with the reflection coefficient of -43.439 dB. Since the introductory of U-slot is not sufficient to suppress the harmonics of higher than 5.00 GHz, stub is introduced to the feed line. [...]the U-slot with symmetrical left-right-handed stub is analyzed and the reflection coefficient at 2.45 GHz is -18.889 dB and at 5.00 GHz is -19.416 dB.