[en] The ICRF system of ITER must couple 20 MW to the plasma in the frequency band 40 - 55 MHz through a surface of ∼ 1.5 m x 1.9 m, with a wave spectrum appropriate for both heating and current drive. Its matching system must furthermore be resilient to the large load variations that are typically for ELMy discharges. A compact ICRH antenna concept where 24 radiating straps are grouped in 8 triplets by passive junctions has been selected. In view of its complexity the matching systems are studied and tested on a scaled down mock-up. When decreasing the lengths and increasing the frequency by the same scale factor the impedance matrix of the array remains identical realistic simulation of plasma-like load conditions can be obtained by facing the strap array by means of a large dielectric constant medium, such as water. The two selected matching network options to provide the needed load resilience are (i) 4 'conjugate T' (CT) circuits, or (ii) 4 hybrid junctions with reflected power dumped in dummy loads. Two challenges have to be faced hereby: (i) Due to the compactness of the array the mutual coupling effects between the radiating triplets are important and lead to a coupling between all matching actuators and power sources and to an asymmetry in the radiated power distribution. (ii) The low range of antenna loading resistance to be expected in ITER because of the large antenna-LCMS distance renders the adjustment of the matching circuits very critical and amplifies the mutual coupling effects. From the present study the following results and conclusions can be drawn: (i) Decouplers neutralizing the dominant coupling terms of the input admittance matrix are mandatory; (ii) Both matching options, if well adjusted, have good performances. The advantages of the hybrid option are its potential resilience for any value of the coupling resistance and its larger insensitivity to reactive load changes. The load resilience domain for the CT option becomes small if the mean plasma loading is too low. The advantages of the CT matching are its requirement of a lower number of components and the lower number of matching parameters requiring feedback control. (iii) For both options the generators must be combined to provide 4 power sources exceeding 5 MW. Matching procedures and automatic algorithms have been developed and were successfully tested on the mock-up. (author)