Multiple Circular-Sector Structures for Wideband Planar Monopole Antenna Designs Covering 146% Fractional Bandwidth

Three wideband planar monopole antennas were designed with multiple circular-sector structures. The radiating elements of the monopoles were composed of multiple circular sectors. These antennas were optimized to satisfy the required omnidirectional radiation pattern for portable devices, and to maximize bandwidth. Simulation and experiment results showed that the antennas reached a fractional bandwidth of at least 146%: a value that was larger than what is required by ultra-wideband antennas having fractional bandwidths of 110%. The frequency range of the proposed designs was 1.8 GHz to 10.6 GHz, which can cover numerous communication standards. Comparisons of the monopoles using multiple circular sectors with other wideband antenna designs are provided at the end of this paper.