This paper introduces a theory for assessing and optimizing the multiple-input-multiple-output performance of multi-port cluster antennas in terms of efficiency, channel correlation, and power distribution. A method based on a convex optimization of feeding coefficients is extended with additional constraints allowing the user to control a ratio between the power radiated by the clusters. The formulation of the problem makes it possible to simultaneously optimize total efficiency and channel correlation with a fixed ratio between power radiated by the clusters, thus examining a trade-off between these parameters. It is shown that channel correlation, total efficiency, and allocation of radiated power are mutually conflicting parameters. The trade-offs are shown and discussed. The theory is demonstrated on a four-element antenna array and on a mobile terminal antenna.
@article{arxiv.2305.01416,
title = {Trade-off Between Optimal Efficiency and Envelope Correlation Coefficient for Antenna Clusters},
author = {Vojtech Neuman and Miloslav Capek and Lukas Jelinek and Anu Lehtovuori and Ville Viikari},
journal= {arXiv preprint arXiv:2305.01416},
year = {2023}
}