Contribution of LPP/ERM-KMS to the modern developments of ICRH antenna systems

•Overview of ICRF antenna coupling physics, showing from first principles how to develop a state of the art ICRF system for ITER and DEMO.•Physics of conceptual solutions for the compact ITER antenna array, intended to radiate ∼10MW/m2.•Implementing novel ideas into the matching-decoupling network of the ITER antenna array to avoid cross-coupling and to control the RF current distribution in the array.•Experimental tests of the theoretical predictions using scaled mock-ups of the ICRF antenna, including a dielectric dummy load to mimick the plasma.•Demonstrating an operational feedback control of the matching-decoupling network for the ITER antenna array, with 23 simultaneously active actuators.