Coupled-fed Printed PIFA for Internal Eight-Band LTE/GSM/UMTS Mobile Phone

A coupled-fed printed PIFA (Planar Inverted-F antenna) for eight-band operation covering the LTE700/2300/2500 and GSM850/900/1800/ 1900/UMTS2100 bands in the mobile phone is presented. The proposed antenna comprises a driven T-monopole and two coupled folded-strips. The folded strip which is coplaner with the T-monopole is called strip 1 and the folded-strip on the back of the system circuit board is called strip 2. The strip 1 is short-circuited to the system ground through an inductance and the Strip 2 is short-circuited to the system ground plane of the mobile phone directly. The driven T-monopole and the strip 1 contribute a wide band for the antenna's upper band (1710-2690MHz), whereas the strip 2 generates a resonant mode for the antenna's lower band (698-960MHz). The antenna's two wide operating bands are achieved and controlled by tuning the width of the T-monopole, the gap g3 between the strip 1 and the T-monopole, and the dimensions of the strip 2 on the back of the system circuit board. Details of the proposed antenna are described, and the obtained results are presented and discussed.