Development of an ultra-wideband elliptical disc planar monopole antenna with improved omni-directional performance using a modified ground

A planar monopole antenna has many attractive features such as a simple structure, exhibition of ultra-wideband characteristics, and a near omni-directional radiation pattern (J. Liang et al., 2004 - Z.N. Low et al., 2005). However, the ability to sustain an omni-directional pattern over ultra-wide band has not been adequately addressed in the literature up until now. The use of a modified ground plane can aid in providing such a feature