Large-spacing patch antenna array based on mutual coupling

The loss and cost introduced by the feeding network and the associated components, e.g. T/R modules or phase shifters and so on, of a large array antenna are the main issue limiting its efficiency and applications. In this paper, a novel idea in order to reduce the number of active elements is presented while keeping similar aperture efficiency by taking advantage of mutual coupling between array elements, and then the total cost of the array are greatly decreased. A simple way to control the mutual coupling of a patch array antenna is exampled in this paper, along with parametric studies. Simulations show that when the active element spacing is as large as 1.57λ (λ is the free- space wavelength at the operating frequency), a -13.8-dB side lobe level and an approximately equal aperture efficiency, compared to an ideal conventional array with a half element spacing (0.785λ) and an identical total size, can be achieved.