Planar Internal LTE/WWAN Monopole Antenna for Tablet Computer Application

By using a T-shaped parasitic shorted strip, this work presents a planar coupled-fed U-shaped monopole antenna with eight-band LTE/WWAN operation in tablet computers. The obtained impedance bandwidths across dual operating bands approach 281 MHz and 1088 MHz at the LTE and WWAN bands, respectively. The proposed uniplanar antenna reduces the antenna size by at least 20% since the overall antenna size is only 50×15×0.8 mm³. The measured peak gains and antenna efficiencies are approximately 2.9/5.4 dBi and 72/80% for the LTE/WWAN bands, respectively. Moreover, with a compact structure, the proposed planar antenna can be deposited inside the tablet computer and complies with the body specific absorption rate (SAR) requirement (1.6 W/kg for 1-g body tissue) for practical applications.