Fundamental approach of isolation loss control between two patch antennas for LTE-MIMO mobile handy terminal

This paper presents fundamental research results to obtain optimal isolation coefficients determined by position between two antennas for LTE-MIMO mobile system. In order to control the isolation loss and the radiation directivity, various antenna positions were considered. It was confirmed that the isolation loss was determined by current direction of two antennas and by current distribution on ground plane. When two antennas had a same current direction, it was satisfied isolation loss of -15 dB below. Otherwise, it had isolation loss of -10 dB above. Radiation pattern is also controlled by current direction and antenna position. The proposed LTE-MIMO antennas with different tilting radiation direction as shown in (1-2) and (4-1) of Fig. 4 (b) and Fig. 6 (b) is a good ECC candidate. The measured return loss and radiation pattern of a fabricated PIFA were also observed reasonable agreement with the prediction.