Broadband Duplex Slot Antenna Array with High Isolation

This letter presents a broadband duplex slot antenna array with high isolation performance. The slots in the proposed duplex antenna acts not only a radiating element but also a resonant elements. The feeding networks of this antenna array in transmitting (Tx) and receiving (Rx) bands are realized through even-mode of a common double-mode resonator. By coupling the feeding networks to the specified position of the 1-shaped slot locating on the ground, three resonant modes appear on the Tx and Rx bands. Increased resonant modes increase antenna bandwidth. For demonstration, the duplex slot antenna array is fabricated and measured. The impedance bandwidths of the lower-and upper-band channel are 11.4 % (1.90-2.13 GHz) and 11.3 % (2.50-2.80 GHz), respectively. High isolation of better than 30 dB is realized between the two channels.