Characteristics of planar and orthogonal planar monopole antenna with dual frequency for UWB system

Since the UWB system covers from 3.1 to 10.6 GHz, it is necessary to suppress the interference from other systems using some of the 3.1-10.6 GHz frequency band. Two types of novel planar monopole dual frequency antennas, which consist of two connected elements, are presented. These antennas are like slitted planar monopole antennas, and one of the presented antennas is the novel orthogonal planar monopole antenna. The proposed planar and orthogonal planar monopole antennas' structures have dual frequency and broad bandwidth characteristics at both resonant frequencies. The return loss level at the suppressed frequency between both resonant frequencies is almost 0 dB. The radiation patterns at all frequency ranges are almost omnidirectional in the horizontal plane.