Integration of T-shaped Notch Filter Elements into a UWB Antenna to Reduce EMI of WiMAX/N78 and N79 Bands

This study introduces an ultra-wideband (UWB) antenna with dual-band notches featuring T-shaped notch filter elements to effectively suppress the interference caused by WiMAX/N78 (3.37-3.72 GHz) and N79 (4.57-5.05 GHz) bands. The compact antenna, measuring 26×28×0.8mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>, is modeled on an FR-4 substrate characterized by a dielectric constant of ϵ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf> = 4.3, a loss tangent of tan δ = 0.02, and a thickness of 0.8 mm. It achieves a wider -10 dB impedance bandwidth (2.97 GHz to 10.76 GHz) with a VSWR < 2, except in the notched bands where the VSWR exceeds 2, confirming effective EMI suppression. The gain varies between 1.99 dBi and 3.05 dBi, with notable reductions in the interfering bands. The design exhibits high radiation efficiency above 80%, peaking at 95% at 3 GHz. These results validate the antenna’s suitability for interference-free operation in the WiMAX/N78 and N79 5G sub 6 GHz spectrum in real-world UWB applications.