Partial Reflective Decoupling Superstrate for Dual-Polarized Antennas Application Considering Power Combining Effects

A decoupling design based on metasurface partial reflective decoupling superstrate (M-PRDS) for closely arranged dual-polarized antennas with power combiners is proposed in this communication. Compared with the coupling between each separate antenna element in the array, the introduction of the power combiners makes the mutual coupling between antenna subarrays rearranged and, consequently, more complicated. Therefore, the proposed M-PRDS technology is required to consider the abovementioned power combining effect. The combined mutual couplings are analytically calculated in the first place, and then, a dielectric PRDS (D-PRDS) with given permittivity and height is introduced to create a proper partial reflection for the combined couplings. Finally, an M-PRDS of periodic nonresonate structures with the equivalent electromagnetic parameters as the designed D-PRDS is utilized in this work using simple printed circuit board technology, which not only can achieve the same decoupling effect as the D-PRDS but also possesses the low cost, lightweight, and easy fabrication features. Measurement results of the fabricated prototype composed of 4 × 4 dual-polarized antennas with eight power combiners confirm that all types of mutual couplings can be suppressed to below-25 dB in the operating frequency band (1.7-2.3 GHz).