Analysis and Design of Shorted Rectangular Slot cut Semi-Circular Patch Microstrip Antenna

Wide band design using rectangular slot which is embedded inside shorted semi-circular microstrip antenna is reported, that gives bandwidth from 1860 to 2580 MHz (32.4%). In the reported work, an in-depth explanation about working of antenna is not provided. Work proposed in this paper gives detail explanation about functioning of shorted antenna. It clearly reveals that slot alters and tunes shorted patch second order mode frequency with reference to fundamental mode that yields wider bandwidth. Slot re-orients surface currents at second order mode to yield pattern maximum in broadside direction. Further in the proposed work, design procedure to realize similar broadband design on thicker air substrate at different equivalent TM11 mode resonant frequency is outlined. This methodology yields similar wide band response with bandwidth of more than 30%.