Dual Stopbands Ultra-Wideband Antenna with Defected Ground Structure

A novel compact ultra-wideband (UWB) microstrip-fed planar monopole antenna with dual band-notched characteristics is presented. By etching two simple U-shaped defected ground structure (DGS) with different length in the feedline, the dual stopbands can be obtained respectively. The expetimental results show that the proposed antenna achieved an impedance bandwidth of 3.1–10.6 GHz with VSWR < 2, except the bandwidths of 3.3–3.8 GHz for worldwide interoperability for microwave access (WiMAX) and 5.1–6.3 GHz for wireless local area network (WLAN) application. The fabricated antenna also shows the broadband impedance-matching, stable gain, good group delay and approximate omnidirectional radiation patterns across the major bandwidths.