Design of Compact Monopole UWB Antenna with Dual Notched-Band Characteristics using Pair of Elliptical Split-Ring Slots

In this paper, a novel design of compact microstripline-fed ultra-wideband (UWB) antenna with dual notched-band characteristics is presented. By etching a pair of elliptical split- ring slots on the radiating patch the dual notched-band characteristics are realized. The separate band-rejected characteristics are achieved at 3.5 and 5.75 GHz which covers a WiMAX (3.3-3.7 GHz) and WLAN (5.725-5.825 GHz) operating ranges respectively by adjusting the length of the elliptical split-ring slots. The proposed UWB antenna has the size of 26 × 32 mm2 which is printed on a low cost FR4 dielectric substrate having a relative permittivity (εr) of 4.4 and a loss tangent (tan δ) of 0.02 with a substrate thickness of 1.6 mm. The total length of the elliptical split-ring slots which affects the performance of the dual band notched characteristics and corresponding VSWR plots are investigated in this paper. The simulated result of the proposed antenna is presented and shows a good agreement with measured one. Moreover, the proposed antenna exhibits omnidirectional radiation characteristics with stable gain across the UWB range expect at 3.5 and 5.75 GHz which meets a real requirement for UWB applications.