A 28 GHz FR-4 Compatible Phased Array Antenna for 5G Mobile Phone Applications

The design of a 28 GHz phased array antenna for future fifth generation (5G) mobile-phone applications has been presented in this paper. The proposed antenna can be implemented using low cost FR-4 substrates, while maintaining good performance in terms of gain and efficiency. This is achieved by employing a new air-filled slot-loop structure as the radiator. A prototype array consisting of ten radiator elements has been designed for concept validation. Both the radiation and total efficiencies of the antenna array are higher than -0.5 dB (90%) for the scanning range between 0 degrees to 50 degrees, while the gains are higher than 13 dB. In addition, the simulated and experimental results show that the antenna has the S-11 response less than -10 dB in the frequency range of 27 to 29 GHz.