Design of MIMO terminal antennas with user proximity using characteristic modes

Abstract

Abstract-Although the classical Theory of CharacteristicModes allows an arbitrary structure to be analyzed prior to the implementation of physical feeds, structures containing dielectrics have so far received very little attention. Recently, a mesh perturbation method is proposed to remove internal resonances from the characteristic mode (CM) solution for lossy dielectrics obtained using the computationally efficient surface integral equation. Herein this method was applied to extract the CMs of a lossy structure consisting of a terminal chassis held in a user hand. These modes were then individually analyzed and a subset was chosen to design a MIMO antenna with not only very low correlation, but also low hand-induced losses.

Preliminary Study on Differences between Full- and Sub-Structure Characteristic Modes

“…Characteristic mode (CM) analysis is a popular topic in the antenna community as it provides useful physical insights for understanding the radiation mechanism of various antennas [1], [2]. A suitable choice of significant CMs and their excitation method can yield antenna designs that meet tough requirements, e.g., [3]. However, electrically large structures lead to large mesh sizes and large increases in the number of significant modes [4].…”