Dual-polarised high-gain triple-band differential antenna for WLAN and Sub-6 GHz 5G applications

A new dual-polarised high-gain triple-band differential-fed antenna is proposed in this study. The antenna adopts a differential feeding scheme, in which a high-frequency radiator for 3.5 GHz Sub-6 GHz 5G band and 5 GHz WLAN band, and two pairs of low-frequency radiators for 2.45 GHz WLAN band are effectively combined to obtain multiband operation. To filter out unwanted frequency band, four half-wavelength slots are introduced to generate a notch band between 3.8 and 4.8 GHz. Experimental results show that the proposed antenna achieves 10-dB impedance bandwidths of 2.37-2.61 GHz for the low-frequency band, 3.27-3.76 GHz for the intermediate frequency band, and 4.87-5.98 GHz for the high-frequency band. The gains of the antenna are all above 8.0 dBi for all the three bands. The antenna exhibits a good directivity and low cross-polarisation level (below -20 dB); thus it is a good candidate for WLAN and Sub-6 GHz 5G wireless access point systems.