Résumé : Ion cyclotron Resonance Heating (ICRH) is one of the auxiliary heating schemes considered for the future DEMOnstration Power Plant (DEMO). The ICRH system in DEMO should couple 50 MW using three equatorial ports. Compared to the ITER one, the current DEMO port design has a smaller toroidal and a larger poloidal extent. One of the ICRH pre-conceptual design options for DEMO, an in-port antenna based on the current ITER design, is investigated using the ANTITER II code. To make optimal use of the port larger poloidal extent, the possibility to use quadruplets instead of the ITER triplets is explored. The impact on the power coupling is evaluated for two different antenna geometry considering a possible toroidal extension of the antenna in the blanket. The ITER matching-decoupling system is adapted to the new antenna front geometries considered.