Design of compact octagonal slotted hexagonal and rectangular shaped monopole antennas for dual/UWB applications

applications are proposed in this paper. In both antennas, the slot in the ground plane is of octagonal shape, while the patch is rectangular in one of the antennas and hexagonal in the other. Thin metallic stubs of different lengths are added to the ground plane and protrude into the slot. These stubs help to improve the impedance matching over a broader bandwidth. The antennas are very compact in size and designed on low-cost FR4 substrate. The measured impedance bandwidths (S$_{11}