Alias H.,Antenna Research Group |
Ali M.T.,Antenna Research Group |
Kayat Muhamud S.,Antenna Research Group |
Ramli N.,Antenna Research Group
International Journal of Microwave and Optical Technology | Year: 2014
This paper presents a novel design of aperture coupled microstrip antenna (ACMSA) integrated with Defected Ground Structure (DGS) and parasitic elements. The basic design of the proposed antenna used 2 by 2 planar array structures with aperture coupler feeding technique. Four DGS with dumbbell shape are etched on the ground plane, for back radiation reduction, which is sandwiched between the upper and lower substrates. Both of the substrates are Rogers Duroid 5880 of thickness 0.787mm with dielectric constant of 2.2. Twelve trapezoidal-shaped parasitic elements are placed onto the first substrate, three elements besides each patch. The antenna design is simulated in CST Microwave Studio 2011 software based on operating frequency of 5.8 GHz. The results show that back lobe level is reduced from 4.6 dB to 0.1331 dB. The gain of the antenna was dropped from 11.8 dB to 11.2 dB when DGS is added. However with the parasitic element, it is improved to 11.5 dB. A significant improvement can be seen to the front-to-back ratio of the antenna. With the addition of DGS and parasitic element, the ratio improves from 7.2 dB to 11.37 dB. Return loss of the antenna is -27.50 dB. This design concept can be useful in reducing the back radiation of aperture coupled microstrip antenna and improve the front-to-back ratio. © 2014 IAMOT.