Microstrip Bowtie Antenna with Patch and

In this paper, a fractal-based bowtie microstrip antenna with defected ground structure for Wireless Local Area Network (WLAN) applications is proposed and studied. To achieve a dual band operation (i.e., 2.4 GHz and 5.2 GHz unlicensed bands), the initial design of the proposed antenna is based on the Sierpinski gasket (triangular) fractal geometry. However, it is well known that, at the fundamental resonant frequency of the Sierpinski gasket, the input impedance match is too poor. To overcome this problem, a circular split ring resonator (CSRR) is used as a defected ground structure to achieve efficient coupling at the fundamental resonant frequency. The proposed antenna is designed and analyzed using the finite element method. To this end, the High Frequency Structural Simulator (HFSS) of ANSYS is employed. The proposed fractal bowtie antenna with CSRR features low profile, high return losses, dual band operation, and moderate coupling bandwidth (around 4 %). Simulation results show that the antenna presents return losses of -19 dB and a coupling bandwidth of 120 MHz at the first resonant frequency (i.e. 2.4 GHz), while the corresponding values at the second resonant frequency (i.e., 5.2 GHz) are -46 dB and 190 MHz, respectively. These results show that the proposed antenna is suitable for WLAN applications.