A radiating phase-shifting cell is designed to favour the excitation of an equivalent resonance of the “slot” type in a first part of the phase cycle, and to favour an equivalent resonance of the “microstrip” type in a second part of the phase cycle. This property notably allows the bandwidth of the phase-shifting cells to be optimized. A phase range of 360° can in effect be segmented into two sub-ranges of around 180°. This segmentation into two sub-ranges is made possible by the complementarity of the resonant modes of the slot or microstrip type. The radiating phase-shifting cell is notably applicable to reflector arrays for an antenna designed to be installed on a space craft such as a telecommunications satellite or on a terrestrial terminal for satellite telecommunications or broadcasting systems.