Size miniaturization of slit-based circular patch antenna with defected ground structure

Abstract

This letter proposes a novel compact circular patchantenna that is simulated, fabricated, and measured for different wire-less applications. Traditional circular antenna is modified with dual T-shaped slits placed on top and bottom positions, to obtain the tri bandresonant frequencies. Metallic ground plane behind the radiating patchis placed with a dual E-shaped defected ground structure (DGS) achiev-ing size miniaturization and bandwidth (BW) enhancement at dualbands. Antenna is well performed with and without placement of DGS interms of obtained gain. Shape, dimensions of the finite ground plane,and frequency shift property using defect on the patch are the key fac-tors in improving the BW and reducing the size. BWs of 3.9 and 3.6%are obtained for 1.56 and 2.47 GHz bands, respectively. The optimizeddimensions of DGS are selected without degrading the antenna perform-ance. This single layer probe feed antenna is analyzed, simulated usingIE3D tool and also performed experimentally. Frequency shift techniqueof DGS would attain compact antenna size and is also capable of pro-viding dual bands with better impedance matching and acceptable gain.