Sierpinski Gasket fractal antenna with ring-shape defected ground structure for RFID application

A prototype modified Sierpinski gasket fractal antenna with ring-shape defected ground structure (DGS) at center frequency of 5.8 GHz was designed and simulated using Computer Simulation Technology (CST) software and fabricated. RT Duroid/RO5880 substrate with dielectric constant, ε_r of 2.2 with thickness of 0.381 mm was used. The Vector Network Analyzer (VNA) was used to measure the parameters of the antenna such as return loss, VSWR and input impedance. A ring-shape defected ground structure was proposed to improve the overall performance of the antenna. The simulated and measured results were close with each other and achieved the required specification for this work at 5.80 GHz with the return loss of -25.307 dB and unidirectional radiation pattern was realized. There was a significance reduction in size of the prototype antenna and this suits well with the current requirements for mobile wireless devices.