Design of Multiband UWB Planarized Monopole Using DMS Technique

A variation of the novel technique called defected microstrip structure (DMS) is employed to enlarge the bandwidth of a planarized ultrawideband (UWB) monopole. It is demonstrated that introducing a defect in the feeding microstrip line, the lower bandwidth limit is lowered without affecting the antenna gain and radiation pattern. The bevel technique in the ground plane near to the feeding point is used to increase the highest bandwidth limit. By using these techniques, a 50 mm times 50-mm planarized omnidirectional antenna was developed, achieving a voltage standing wave ratio (VSWR) < 2 from 2.1 to 12.3 GHz