A compact folded loop antenna for LTE/GSM band mobile phone applications

This paper presents a multiband meandered loop antenna presently being used in LTE/WWAN systems for smart phone applications. The proposed antenna which features a meandered folded-loop generates two resonance modes in the LTE/GSM bands. The mode characteristic is characterized as a parallel monopole-like mode combined with a PCB ground plane mode. By using an inverted-L-shape capacitively-coupled element connected to the feed port on the backplane, the impedance bandwidth is broadened to cover LTE700/GSM850/GSM900/PCS/UMTS/LTE2300 bands. The simulation performed in this research used a high frequency structure simulator (HFSS) to optimally design the antenna, and a practical structure was constructed for the test. Details of the proposed antenna parameters, including reflection coefficient, radiation characteristics, peak gain, and radiation efficiency are presented and discussed in this paper.