Optimization of Fractal Antennas for RFID and Wireless Communication

The required antenna design should have a small size, lower weight, and should operate in multiple frequency bands, have high radiation efficiency, and low loss in high frequency while considering the minimum cost. By adopting the fractal geometries to create antenna-radiated elements, the designed antennas have significantly improved antenna features. Firstly, a rectangular microstrip antenna is designed and analyzed for the Radio Frequency Identification system. The reducing dimension of the antenna is achieved using the third iteration of the Koch fractal, which is optimized using Ansoft/HFSS software. Considering the results, the proposed antenna operated a stable radiation pattern at 868 MHz, 2.4 GHz, and 6 GHz. Secondly, the fractal geometry was applied to the antenna radiator. The two-sided, third iteration of the Koch fractal has been used to increase the electrical current path on the radiating element surface. The proposed antenna is printed on an FR-4 substrate with a thickness of 1.6 mm and a relative dielectric constant of 4.4 is fed with a 50-ohm microstrip supply line. The resulting antenna dimensions are approximately 45 mm x 41 mm. The dimensions of the antenna have been determined by using the parametric study to be more efficient. It demonstrates that the antenna offers a multiband performance with many resonance frequencies, including many other communication services, as well as the current 2.4 / 5.8 GHz WLAN applications.