A Pattern Reconfigurable Chassis-Mode MIMO Antenna

Reconfigurable multiple-input multiple-output (MIMO) antennas have the potential to improve the performance of a MIMO antenna system operating in a dynamic environment. This paper presents a reconfigurable MIMO antenna that utilizes two tunable parasitic elements that manipulate the characteristic modes of the structure to provide pattern diversity. Simulation studies and calculation of envelope correlation coefficients from this two-port antenna confirm that the radiation patterns are orthogonal to each other in each of the two states of the antenna, as well as between the two states. Measured two-port S-parameters of a prototype employing switched PIN diode loading correspond well with simulations. Radiation pattern measurements in the two principal planes indicate overall correlation with simulations.