Design and analysis of multiband defected ground plane MSA

In this paper a multiband rectangular microstrip antenna, designed by incorporating n-shape slot at appropriate positions on the ground plane is proposed. The slot on ground plane disturbs the modal current distribution on the patch at higher order TM20, TM02 and TM12 resonant modes resulting in reduction in respective modal frequencies. Rectangular patch antenna at these modified resonant frequencies along with fundamental mode frequency of TM10, yields multiband response. The antenna yields 1 to 2% of BW at each frequency. In multi-band antenna, broadside radiation pattern is noted at each of these frequencies.