Dual-band and high-isolation shared-aperture antenna for broadband airborne applications

A dual-band and high-isolation shared-aperture antenna for unmanned aerial vehicle(UAV) platforms has been proposed. This shared-aperture antenna consists of a rectangular monopole antenna and a 4-element multiple input multiple output(MIMO) antenna. In order to increase the isolation, several double split ring metamaterial(MTM) structures are introduced between antenna elements. The antenna radiator and the MTM structure are located on the front and back of the same dielectric substrate, respectively, and are perpendicular to a circular metal plate. The overall size of the antenna substrate is 124 mm×38 mm×1.016 mm. Moreover, the antenna prototype is constructed and measured, and the simulated and measured results are in good agreement.The measured results show that the –10 dB bandwidth of the monopole antenna is 1.92 GHz to 2.75 GHz, and the common –6.0 dB bandwidth of the MIMO antenna element is 4.75 GHz to 4.91 GHz, covering 2.2 GHz to 2.4 GHz in the S-band and 4.8 GHz to 4.9 GHz in the 5G band, respectively. In the 5G band,the isolation between any element of the MIMO antenna and the S-band monopole antenna is not less than 21 dB, and the isolation between the MIMO antenna elements is better than 23 dB, indicating t–hat the isolation between the antenna elements is high. The proposed antenna is suitable for the application on UAV airborne platforms.