Design of a UWB Filtering Antenna with Defected Ground Structure

In this paper, a band-notched UWB filtering antenna with defected ground structure (DGS) is presented. This defected ground structure as a lowpass filter (LPF) plays a role in filtering unwanted band. The DGS is applied to suppress the upper passband spectrum of the proposed antenna. A Ushaped slot line etched in the feeding line creates a single band-notched characteristic in 3.3-3.83 GHz for WiMAX to avoid potential interference with the existing system. The measured return loss has a wide fractional bandwidth up to 127.6%, which covers a range of 2.43-11 GHz, with the return loss higher than 10 dB except notch band and less than 2 dB up to 16GHz. The measured and simulated results reveal that the antenna has good upper stopband performance and consistent quasi-omnidirectional radiation pattern within the UWB frequency range.