Multiband folded loop antenna for smart phones

Abstract—This paper presents a multiband folded loop antenna for smart phone applications. The proposed antenna with a symmetric loop pattern generates four resonance modes in the design bands. The current distributions of the excited resonance modes are analyzed to confirm the mode characteristic. Using a pair of tuning elements near the feed port, the impedance bandwidth is broadened to cover GSM850/GSM900/DCS/PCS/UMTS bands. This research performed simulation by a high frequency structure simulator (HFSS) to optimally design the antenna, and a practical structure was constructed to test. The current study measured the antenna parameters including reflection coefficient, radiation characteristics, peak gain, and radiation efficiency to validate the proposed antenna. 1