A 21.6-45 GHz Low-Profile Wideband Slot Antenna Array for 5G Wireless

In this paper, a low-profile 21.6-45 GHz printed 1x4 antenna array with high gain and efficiency is presented. Such antenna array is composed of an in-phase 1:4 power divider and four slot antenna elements. Each antenna element fed by the 50 Omega microstrip input/output (I/O) port consists of a C-shaped slotline and two ring slots with embedded defected ground structure (DGS). Multiple resonances are introduced by the proposed structure to achieve a wide operation bandwidth. To verify the mechanism mentioned above, a wideband slot antenna array is implemented and fabricated with a compact size of 28x40x0.254 mm(3). The measured result exhibits a 70.3 % impedance bandwidth operating from 21.6 to 45 GHz. With such high performance, the proposed wideband antenna array can be a good candidate for 5G communication systems.