A Dual Band Fractal Slot Antenna Loaded with Jerusalem Crosses for Wireless and WiMAX Communications

In this paper, a combination of the Jerusalem cross (JC) as a fractal load and fractal Minkowski slot antenna for dual-band application is investigated. The prototype slot antenna has a Minkowski fractal formation with four Jerusalem cross (JC) loads to achieve dual-band application with compact size to improve the bandwidth. A T-shaped feed line is implemented in the final modeled antenna. The fabricated antenna has a bi-directional pattern with sufficient bandwidth at 2.4-3.1GHz and 5.1-5.9GHz with VSWR < 2 for Wi-Fi, WiMAX, Bluetooth application as well as an IEEE WLAN protocol with a gain of 5-6 dBi, respectively. The size of the prototype patch antenna is 40x40mm(2), and the antenna is designed and fabricated on an FR-4 low cost substrate with epsilon(r) = 4.4 and thickness of 1.6mm. It is simulated by HFSS full wave software. In addition, the VSWR, pattern and axial ratio of experimental results are presented and compared with simulation models. As a result, improvements of the Jerusalem cross compared with conventional cross have been achieved with some parameter tuning to improve the bandwidth.