Low-Profile Dual Hollow Octagonal Ring Shaped Optically Transparent Tri-band Antenna for WLAN and Sub-6 GHz 5G Applications

A transparent dual octagonal split ring-shaped resonator connected by a horizontal strip is proposed for tri-band applications. Stub-loaded microstrip line fed structural design of radiator consists of two slotted octagonal-shaped rings connected via a strip on the top with the partial ground at the back. The low profile (40×25 mm2) radiator achieves impedance bandwidth of (46.08%) 1.62-2.59,(7.78%) 3.95-4.27, and (12.60%) 5.13-5.82, respectively. A bi-directional (dipole shaped) radiation pattern with maximum gain and minimum efficiency of 2.5 dBi and 52%, respectively is achieved. Transparency above 80%, low profile structure, and tri-band operation make the antenna a good contender for WLAN and Sub-6 GHz 5G applications. Good correlation is observed for the modeled and experimental parameters. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.