High Efficiency Antenna Design for Foldable Smartphone

In this paper, the antenna is proposed to be applied to a foldable smartphone, and the parasitic antenna unit in the secondary screen is used to regulate the working performance of the main antenna unit in the main screen. The efficiency of the antenna of the folded smartphone is improved by continuously optimizing the structure of the parasitic antenna unit in the secondary screen. When the parasitic antenna unit and the main antenna unit have symmetrically positioned feed ports and ground ports, compared to the traditional parasitic branch ungrounded structure, in the folded state, the on-body total efficiency and the on-body radiation efficiency increase 5% and 10%, respectively. The -6dB bandwidth of the antenna can cover the frequency bands from 1.57 GHz to 2.05 GHz in both unfolded and folded states, which helps to improve the communication quality of the folded smartphone.