SIZE MINIATURIZATION OF SLIT-BASED CIRCULAR PATCH ANTENNA WITH DEFECTED GROUND STRUCTURE

This letter proposes a novel compact circular patch antenna that is simulated, fabricated, and measured for different wireless applications. Traditional circular antenna is modified with dual T-shaped slits placed on top and bottom positions, to obtain the tri band resonant frequencies. Metallic ground plane behind the radiating patch is placed with a dual E-shaped defected ground structure (DGS) achieving size miniaturization and bandwidth (BW) enhancement at dual bands. Antenna is well performed with and without placement of DGS in terms of obtained gain. Shape, dimensions of the finite ground plane, and frequency shift property using defect on the patch are the key factors 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 optimized dimensions of DGS are selected without degrading the antenna performance. This single layer probe feed antenna is analyzed, simulated using IE3D tool and also performed experimentally. Frequency shift technique of DGS would attain compact antenna size and is also capable of providing dual bands with better impedance matching and acceptable gain. (C) 2015 Wiley Periodicals, Inc.