High-Isolated Multi-Element MIMO Antennas for Mobile Terminals

In this paper, a high-isolated multi-element linearly-placed inverted-F antenna (IFA) array is proposed for mobile terminals. A hybrid decoupling method is introduced to eliminate several mutual couplings, including multiple decoupling capacitors for the couplings of two back-to-back IFA pairs and T-shaped mode transformers for the rest of the couplings. A twelve-element IFA array is constructed utilizing the hybrid decoupling method as well as the pattern diversity, achieving all the mutual couplings reduced by about 10 dB from 3.3 to 3.8 GHz.