A New High-Isolation Broadband Flush-Mountable Dual-Polarized Antenna

A new broadband flush-mountable dual-polarized antenna with very high isolation is proposed. The antenna is made up of a pair of crossed slots that are fed by two orthogonal microstrip feedlines. A metallic cavity is introduced to back the slot antenna for unidirectional radiation pattern. By setting the microstrip feedlines on two substrate layers separated by a metal ground on which the crossed slots are etched, the antenna achieves a high isolation of 40 dB. The antenna has a broad bandwidth (BW) of about 47%, which is due to the wide crossed slots and the impedance matching of the feedlines. It is shown that the antenna can be easily flush mounted on a metal surface without affecting the high isolation and the broad BW performance. The proposed antenna may be used as flush-mountable antennas in wireless sensor/communication systems for high-speed vehicles/aircrafts.