An improved antenna device is has an external length compensation device, permitting a differing length expansion of the housing/radome relative to at least one of the at least two external mounting devices for fixing the antenna device. At least one of the two mounting devices has an external length compensation device, which covers at least one mounting device and a guide device by means of which the housing/radome may be adjusted relative to the mounting device in one direction of the antenna housing/radome. At least for one path length and the external length compensation device with the guide device is designed such that even with fastened screws, play remains between a section of the housing/radome and a section of the mounting device in order to permit an unhindered compensation movement between the mounting device and the housing/radome.