A novel back lobe reduction technique for microstrip antenna array using partial ground and DGS

Abstract

In this communication, back lobe reduction in microstrip antenna array using partial ground and defected ground structure (DGS) is presented. An eight element rectangular microstrip patch antenna array is designed for Xband frequency of 9.1GHz, with a peak gain of 12.04dBi and back lobe level of -13.75dB. Using partial ground plane technique; the back lobe level is reduced to -18.28dB. Then, by placing defected ground structure (DGS) slots on the ground plane, the S11 is further reduced by 7.65dB and back lobe level is reduced to -18.82dB. This microstrip antenna array with partial ground plane and DGS technique has a peak gain of 12.41dBi. By using this novel technique, the front to back ratio has improved from 19dB to 24.23dB. The Simulations are carried using High frequency structured simulator (HFSS) software and compared with measured results. A difference of 0.96dB is observed between simulated and measured back lobe level.