An RF antenna element with a detuning system in which the RF antenna element comprises a resonant electrically conductive loop. The (de)tuning system comprising a switching element to (de)tune the resonant electrically conductive loop. The (de)tuning system element includes an electroluminescent element coupled to the resonant electrically conductive loop. The (de)tuning system includes a photo-electrical conversion element to detect an electro-luminescent signal from the electroluminescent element.