New theory of isolation between antennas

In EMC study, the interaction of two-antenna system is usually described with isolation between antennas. In this paper, the authors point out the definition of traditional isolation between antennas is unreasonable and it will give incorrect isolation prediction. We put forward definitions of arbitrary isolation, ideal isolation and practical isolation of antennas according to three states of antenna system. With the definition of practical isolation, we can give the best and the worst values of isolation of the actual working antennas by only knowing the indexes of input and output VSWR