Coupling Reduction of Antenna Array El- Ements Using Small Interdigital Capacitor Loaded Slots

Small size capacitor loaded ground plane slots are used to reduce the mutual coupling between elements in a microstrip antenna array design. The proposed compact slots are inserted between the adjacent E-plane coupled elements in the array to limit the propagation of surface waves between the elements of the array. In order to validate the feasibility of the proposed structure, a two-element array with 0.5λo distance between centers of two patches is designed, fabricated, and measured. The measured results show a reduction in mutual coupling of 17 dB obtained between elements at the operation frequency.