Aperture coupled microstrip antenna array integrated with DGS and parasitic elements

This paper presents a novel design of aperture coupled microstrip antenna (ACMSA) integrated with DGS and parasitic elements. The basic design of the proposed antenna is 2 by 2 planar array with aperture coupler feeding technique. Four dumbbell-shaped DGS 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 0.767mm with dielectric constant of 2.2. Twelve trapezoidal-shaped parasitic elements are placed onto the first substrate, three besides each patch, for gain enhancement. The antenna design is simulated in CST Microwave Studio 2011 software based on operating frequency of 5.8GHz. The results show that back lobe level is reduced from 4.6dB to 0.1331dB. With the parasitic element, the gain of the antenna which was dropped, from 11.8dB to 11.2dB when DGS is added, is improved to 11.5dB. Reflection coefficient for the antenna is -27.50dB. This design concept can be useful in reducing the back radiation of aperture coupled microstrip antenna.