28 GHz High gain Slotted Array Antenna with Beam Steering Capability for 5G mm Wave Applications

To address common issues with using the high-frequency millimeter band in 5G communication, an efficient, high-gain, and beam-steerable antenna system is necessary. This study proposes a simple array structure consisting of 10 u-shaped slotted patches operating at 28 GHz. The single element offers good radiation characteristics with a gain of 8.4 dBi and radiation efficiency of over 95% at 28 GHz. The slots of the patch demonstrate strong performance in terms of resonant frequency, gain, and total efficiency. Both the single element and the array antenna have a reflection coefficient of ≤ -10 dB at the resonating frequency and a good 10-dB bandwidth that covers the entire 5G (27.5–28.35 GHz) band. To increase the gain, the antenna element is transformed into a 1×10 array. As a result, the peak gain of the array is successfully boosted to 18.5 dBi with 95% efficiency at the working frequency. Simulations show that the proposed array can cover up to ∓44° with a minimum gain of 12.5 dBi and a side lobe level of -13.4 dB. At the maximum steering angle, the array achieves 93% radiation efficiency and 83% antenna efficiency. Overall, the proposed antenna array demonstrates high performance in terms of gain, efficiency, and beam-steering characteristics, making it a strong candidate for use in upcoming 5G communication systems.