“…To obtain a good bandwidth and efficiency, one common method is to transform the metal rim into an antenna radiator. The metal frame can be divided into two categories: one is the entire metal rim as the antenna radiator [2], [3], [4], [5], [6], [7], and the other is a part of the metal rim as the antenna radiator [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18]. In [2], the whole metal frame was used as a radiator without any other antenna elements, and an inductive coupling feeding source was employed to cover the lower band from 0.8 GHz to 1.0 GHz and the middle band from 1.7 GHz to 2.7 GHz, respectively.…”