A highly compact Fabry Perot cavity-based MIMO antenna with decorrelated fields

This work presents the design of a low profile Fabry-Perot cavity-based multiple-input-multiple-output antenna with low correlation coefficient. The fields of closely placed antenna elements are tilted by using a phase-gradient partially reflective surface (PRS), thereby decreasing the correlation coefficient. The PRS is designed in such a way that its reflection phase is complementary to that of the ground plane. The PRS decorrelates the fields of the two radiating elements when placed at a height of λ/10 above them resulting in a reduction of the correlation coefficient by almost 95% for an isotropic environment. This height is considerably less than λ/4, which has been reported previously.