A Novel Circular Slotted Microstrip-Fed Patch Antenna with three Triangle Shape Defected Ground Structure for Multiband Applications

In this paper, a novel circular slotted rectangular patch antenna with three triangle shape Defected Ground Structure (DGS) has been proposed. Radiating patch is made by cutting circular slots of radius 3 mm from the three sides and center of the conventional rectangular patch structure and three triangle shape defects are presented on the ground layer. The size of the proposed antenna is 38 X 25 mm2. Optimization is performed and simulation results have been obtained using Empire XCcel 5.51 software. Thus, a miniaturized antenna is designed which has three impedance bandwidths of 0.957 GHz,  0.779 GHz, 0.665 GHz with resonant frequencies at 3.33 GHz, 6.97 GHz and 8.59 GHz and the corresponding return loss at the three resonant frequencies are -40 dB, -43 dB and -38.71 dB respectively. A prototype is also fabricated and tested. Fine agreement between the measured and simulated results has been obtained. It has been observed that introducing three triangle shape defects on the ground plane results in increased bandwidth, less return loss, good radiation pattern and better impedance matching over the required operating bands which can be used for wireless applications and future 5G applications