Decoupling of 2-D Antenna Array Based on the Diagonal Mode of the Square Patch Resonator

This paper provides a new decoupling mechanism for 2-D antenna arrays based on the diagonal modes of the square patch resonator. By virtue of the diagonal status of TM10 mode, the resonant properties along all four sides of the patch become consistent, resulting in consistent mutual coupling between antenna elements independent of the coupled edges. On this premise, in order to generate the transmission null for decoupling, the patch resonators are adjusted to provide the proper electric and magnetic coupling. For demonstration, two prototypes of $1 \times 2$ and $2 \times 2$ antenna arrays are designed and constructed.