A Narrow Beam Gain Enhanced Wideband Antenna Array Using Slits, I-Slots, and L-Shaped Reflector for 5G Millimeter Wave Applications

In this paper, a planar antenna structure-based compact high gain wideband antenna array is presented for 5G millimeter wave applications. The proposed array uses a 1-to-8 power divider to feed eight antenna elements arranged linearly. To enhance the gain, multiple slits and I-slots are placed on the ground plane and feeding network, respectively. To further improve the gain of the design, an L-shaped metallic reflector is positioned at the optimum distance. With a large 10 dB bandwidth of 35.93% from 22.6 to 32.5 GHz, the proposed antenna array operates in the two 5G bands of 26 GHz and 28 GHz. The proposed antenna array’s measured gain varies from 9.18 to 13.22 dBi which is higher than the gain of 6.60–10.45 dBi of the unmodified array for the entire operating range. The antenna array shows a narrow beamwidth of 6.25° in its E-plane and radiates in end-fire direction. The overall dimension of the proposed antenna array is 57 mm × 25.978 mm × 0.787 mm, which features a simple, compact design. This antenna can be used for millimeter wave application as it fulfills all the requirements of future 5G applications at 26 and 28 GHz bands.