A simple and compact CPW-fed UWB printed monopole antenna with defected ground structures

A planar simple and compact monopole antenna for UWB applications is proposed with CPW feeding. The radiating patch of the antenna consists of a top-cut half-circle together with a triangle on the lower edge. The bottom side of the antenna includes a rectangular defected ground plane with two different symmetrical bevels. By cutting out these bevels on the ground plane, bandwidth coverage of the overall UWB range except 5.4-7 GHz frequency band is provided. To enhance input impedance bandwidth characteristics at 5.4-7 GHz frequency band, dimensions of the triangular part on the lower edge of the patch and top-cut half-circle part on the upper edge are optimized. The overall size of the proposed antenna is 22×20×1 mm³. Simulations are carried out using commercially available ANSYS´s HFSS program which uses the finite element method (FEM). Results show that 110% of the impedance bandwidth between 3.6 and 12.2 GHz for VSWR<;2 is achieved. Moreover, antenna has a stable omnidirectional pattern at XZ plane over the frequency band. Also, the presented antenna is fabricated on FR4 substrate and it is measured.