U-slot cut shorted square microstrip antenna

By cutting U-slot, bandwidth of shorted square microstrip antenna has been increased. Here, detailed analysis which explain the effects of U-slot to achieve wide band response in shorted square patch is presented. U-slot yields tuning of TM_3/4,0 mode frequency with respect to shorted patch TM_1/4,0 mode, thereby it gives 27% of bandwidth in 2.4 GHz range. Slot also modifies current distribution at second order mode to give broadside radiation pattern over the bandwidth. An insight into the functioning of widely reported U-slot cut shorted square patch antennas in terms of patch resonant modes is provided here. This study will serve as a tutorial to re-design similar antennas at any given frequency.