Abstract: In a radar, a protective radome is placed in front of a to-be-protected antenna. The antenna is made of several networks that are superimposed. At least one of the active networks can be controlled electrically in two distinct states A or B. In state A, the radome, which is placed in front of the antenna, is transparent for the radar operation frequency band and reflective outside that band. For state B, the radome is reflective for all radar frequencies. The invention especially protects the radar against jammers that transmit outside the radar operation frequency band, while providing for the total camouflaging of the radar when it is not being used.