Radiation device and multi-band array antenna

The embodiment of the invention provides a radiation device and a multi-band array antenna, which relate to the technical field of antennas, and can integrate more radiation devices under the condition that the size of the multi-band array antenna is not increased or is slightly increased. The radiation device comprises a radiation module, a first wire balun and a second wire balun, wherein the first wire balun and the second wire balun are mechanically connected below the radiation module; the radiation module comprises a first radiation unit and a second radiation unit which are located in the +45-degree polarization direction, and a third radiation unit and a fourth radiation unit which are located in the -45-degree polarization direction; the first wire balun is configured to feed a first differential signal to the first radiation unit and the second radiation unit; the second wire balun is configured to feed a second differential signal to the third radiation unit and the fourth radiation unit; and the f