Half U-Slot and Rectangular Slot Loaded Nearly Square Microstrip Antennas for Wideband Response

Abstract

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 TM 11 , TM 20 , TM 02 , and TM 30 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.