Design of the built-in LTE antenna of laptop computers for 4G communication

A coupled-fed shorted monopole with a planar inverted-F antenna(PIFA) feed structure as an effective radiator for eight-band LTE operation in the laptop computer was presented. The antenna used a 50 Ω coaxial cable to feed signal into PIFA branch, and thus the energy of PIFA branch was fed into the shorted monopole branch due to the coupling effect of the capacitors. The coupling of the two branches produced multiple resonant modes, broadening the antenna band. The measured results show that the efficiency of the proposed LTE antenna exceeds 47%, with a return loss of less than -6 dB. The advantages of the presented antenna include its simple structure, broadened bandwidth, easier manufacturing and lowered cost, compared with conventional LTE antennas.