Wideband designs of nearly square microstrip antenna using two half U-slots and rectangular slots are proposed. The slots optimize the spacing in between the patch modified TM11, TM20, TM02, and TM30 resonant modes, to yield wideband response. The design with two half U-slots yields bandwidth of around 1000 MHz (~50%) whereas that with an additional rectangular slot yields bandwidth of 1345 MHz (~61%). Due to the presence of higher order modes, the proposed design offers higher cross polar radiation pattern across the entire bandwidth with the gain greater than 5 dBi. The formulations for the modified patch modes and subsequent redesign procedure are presented, which serve as a guideline in the designing of similar antennas around specific resonance frequency. With the given antenna characteristics, the proposed antennas will find applications in personal and mobile communication systems.
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