Tunable Triple-Band Antenna for Sub-6 GHz 5G Mobile Phone

In this paper, the new design technique of the triple-band antenna for the sub-6 GHz 5G mobile phone is proposed. The new proposed patterns are designed into a metal clearance area with the pre-existing 4G antennas in order to cover the additional sub-6 GHz bands. In the proposed design, and the tunable inductor is placed between the legacy antenna and the proposed patterns to cover the wide frequency range in the sub-6GHz bands through the frequency switching without loss of the pre-existing 4G antennas. Consequently, the proposed antenna operates in triple-band (0.9 GHz, 2.5 GHz for the legacy band, 3.3 - 5.0 GHz for the sub-6 GHz) and the simulated and measured radiation efficiency is over 50% in whole target frequency bands. The proposed design technique can contribute to various mobile phones which need to add the new 5G band without the additional space.