A Low Profile Dual-Band Ring Slot Antenna for 5G Mobile Handsets

A low profile circular ring slot antenna structure for 5G mobile handsets applications is presented. The proposed antenna is composed of a concentric single-ring slot antenna that has been optimized to achieve dual-band radiation at 3.5 GHz and 5 GHz. The proposed circular ring is etched on the ground plane of the bottom layer of the FR4 substrate with a 50-ohm microstrip single feed line on the top layer of the substrate of size 50 mm × 50 mm and a thickness of 1.6 mm. The antenna is considered as low profile given the thickness has been found to be 0.018λ. Based on the full-wave simulation results, the antenna shows an impedance matching bandwidth ranging from 3.17 GHz to 4 GHz, centered at 3.5 GHz which correspond to 23.7% of fractional bandwidth and from 4.45 GHz to 5.42 GHz, centered at 5 GHz with 19.4% of fractional bandwidth. The gain of the dual-band antenna has been found to be 4.41 dBi and 2.89 dBi at 3.5 GHz and 5 GHz, respectively.