Compact Ultra-Wideband Monopole Antenna with Enhanced Bandwidth and Dual Band-Stop Properties

In this manuscript, a new design of ultra-wideband (UWB) monopole antenna with dual band-stop performance is proposed. The configuration of the antenna consists of a pair of coupled U-ring structures as a radiating patch, and a modified ground plane with inverted T-shaped strip and a pair of T-shaped conductor-backed plane. In the presented structure, by using an inverted T-shaped strip and also by embedding a pair of T-shaped parasitic structures in the ground plane, additional resonances at the higher band are excited which provides a wide usable fractional bandwidth of more than 135%. In order to generate single and dual band-notched characteristics, we convert the square radiating to the pair of coupled U-ring structures. The measured results reveal that the presented dual band-notched monopole antenna design exhibits an operating bandwidth (VSWR<2) form 2.81 GHz to 15.12 GHz with two notched bands, covering the 5.2/5.8 GHz, 3.5/5.5 GHz, 4 GHz to suppress interferences from wireless local area network (WLAN), worldwide interoperability microwave access (WiMAX), and C-band systems, respectively. Good return loss, antenna gain, and radiation pattern characteristics are obtained in the frequency band of interest. The configuration of the proposed monopole antenna is simple, easy to fabricate, and can be integrated into any UWB system. (c) 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:346-357, 2015.