Wideband Beam-Switchable 28 GHz Quasi-Yagi Array for Mobile Devices

The goal of this paper is to propose a new antenna array architecture that aims to solve the most known limitations of phased antenna arrays, resulting a good candidate for next 5G mobile handsets. The architecture consists of five quasi-Yagi antennas printed on the short edge of a Roger RO3003 substrate, pointing in different directions, and a switch to feed each antenna and steer the beam. Simulations prove that the antenna array can cover the angle of over 180° with high gain over the frequency range from 26 to 40 GHz. Alternative designs to make the structure more compact further demonstrate the validity of the concept. The optimized corner array of four elements is fabricated and passive and active measurements are performed with the Microwave Vision Group (MVG) Starlab 50 GHz. The results of the passive measurements are in accordance with the simulations and show that the proposed quasi-Yagi antenna array has large coverage over the whole bandwidth and peak gain of 8 dBi at 28 and 38 GHz. The active measurements of the array connected to the front end module (FEM) and integrated in the phone case further confirm the radiation properties of the switchable antenna array at 28 GHz in a quasi-real scenario.