Mutual coupling reduction between closely-packed MIMO PIFA arrays

A novel solution for reducing the mutual coupling between two closely packed Planar inverted-F antennas (PIFAs) positioned on a compact ground plane is presented. A single miniaturised convoluted slit with optimised dimensions is introduced between the two PIFAs. The presence of the slit leads to a significant reduction of the mutual coupling in the antennas´ operation frequency band. The proposed slit has a small footprint and is positioned close to the edge of the ground plane thereby occupying very little space. The configurations of the PIFAs are studied and results obtained in 3D electromagnetic simulation software (CST Microwave studio) are presented. A prototype has been fabricated and tested in order to validate the simulation results.