Design and Optimization of a Multiband Extra Wideband Ring Patch Antenna for 5G mm-Wave Communication at 28/60/80 GHz Using MLPNN based K-fold cross validation methodLahcen Sellak, Asma Khabba, Jamal Amadid, Samira Chabaa, Saida Ibnyaich and Abdelouhab ZeroualITM Web Conf., 69 (2024) 04003DOI: https://doi.org/10.1051/itmconf/20246904003