A Flexible Ultra-Wideband Notched Antenna Based on EBG Array for WiMAX/WLAN Interference Suppression

This paper presents a novel flexible ultra-wideband (UWB) antenna with notch characteristics in the WiMAX and WLAN frequency bands. The antenna employs flexible polyimide (PI) as the substrate material, offering excellent conformability to the human body. A coplanar waveguide (CPW) feeding structure is adopted to optimize impedance matching, while a defected ground structure (DGS) is introduced to achieve broadband performance. The antenna effectively suppresses interference from WiMAX and WLAN systems within the operating frequency range of 3.02–10.6 GHz. To mitigate electromagnetic interference when in contact with the human body and to enhance biocompatibility, a 2×2 electromagnetic bandgap (EBG) array is integrated on the backside of the antenna. This configuration significantly suppresses backward radiation and reduces the specific absorption rate (SAR). Simulation results incorporating a human body model demonstrate that the SAR values of the proposed UWB antenna are well below the limits specified by the FCC, ensuring its safety in wearable applications. Further studies confirm that the antenna maintains stable electrical performance under bending conditions, indicating its strong potential for applications in health monitoring and wearable biomedical devices.