User Impact on Phased and Switch Diversity Arrays in 5G Mobile Terminals

In this paper, a mobile terminal phased array at 28 GHz with different scan angles is compared with a switch diversity antenna array at 28 GHz in the case of antenna beams pointing at the user's body. In the switch diversity antenna array, there is only one element out of eight operating each time. The paper is carried out in data mode with a standing user, which includes both body blockage and user hand effects. The metrics of coverage efficiency, antenna shadowing power ratio, and isotropic antenna shadowing power ratio are utilized in the investigation. It is found that the scan angle of a phased array higher than 90° is not necessary for this scenario, because the user body will contribute to the total radiation at large angles by scattering the radiated energy around the body. For the linear phased antenna arrays on the edge of the mobile device ground plane, it can be concluded that in order to achieve the highest coverage efficiency and lowest user shadowing it is more beneficial to use a phased array instead of a switch diversity array. However, if the losses of the phase shifters and the feeding network from the phased array are higher than 5 dB, the switch array can be used, which will also decrease the complexity of a system.