Planar multi-band monopole antenna for WWAN/LTE operation in a mobile device

By using the loop parasitic shorted strip, a small-size uniplanar antenna with multi-band WWAN/LTE operation in the mobile device is proposed. The obtained impedance bandwidths across dual operating bands approach 277 MHz and 1176 MHz at the LTE and WWAN bands, respectively. The proposed uniplanar antenna reduces the antenna size by at least 22% since the overall antenna size is only 35 × 10 × 0.8 mm³. The measured peak gains and antenna efficiencies are approximately 2.6/3.8 dBi and 83/81% for the LTE/WWAN bands, respectively. Moreover, with a compact structure, the proposed planar antenna can be deposited inside the mobile device and complies with the body specific absorption rate (SAR) requirement (<; 1.6 W/kg for 1-g body tissue) for practical applications.