A compact 3.5/5.5 GHz dual band-notched monopole antenna for application in UWB communication systems with defected ground structure

A compact ultrawideband monopole antenna having dual band-notched characteristics with a defected ground structure (DGS) proposed. Two symmetrical L-shaped slots are created on the ground plane to generate the UWB characteristics in the proposed antenna. To generate the notch at 5.2/5.8 GHz band, a U-shaped slot is cut in the rectangular radiating element, which mitigate the potential interference with WLAN. To have another notch band simultaneously around 3.0/4.0 GHz, which is the operating band of WiMAX (3.3–3.6 GHz) and C-band (3.7–4.2 GHz), an inverted U-shaped element is printed on the opposite side of the substrate. By properly varying the dimensions of the U-shaped slot and the radiating element, not only two controllable notch resonances, but also a very wide bandwidth from 1.91 GHz to 3.91 GHz (152%) with two sharp notched bands covering all the 3.5/5.5 GHz WiMAX, 4 GHz C-band and 5.2/5.8 GHz WLAN, are achieved. The proposed antenna properly optimized and simulated providing broadband impedance matching, appropriate gain and stable radiation pattern characteristics.