Modified designs of broadband E-shape microstrip antennas

Wideband designs of rectangular microstrip antennas embedded with three rectangular slots are proposed. These slots modify resonance frequencies of patch's TM10, TM02 and TM11 mode, to give bandwidth of more than 500 MHz (50%). Further, pair of slots cut variations of rectangular patch with three slots is proposed. Additional pair of slots tune the next higher order TM12 mode frequency with respect to modified lower order resonant modes, resulting in further increase in bandwidth of more than 600 MHz (>55%). Increased bandwidth obtained in the proposed designs is more than that obtained from equivalent E-shape and U-slot cut patches. As compared with -shape patch antenna, the proposed configurations yield wider bandwidth with 38% reduction in patch size.