Wideband Two-Layer Transmitarray Antenna Based on Non-uniform Layers

In this study, a wideband transmitarray antenna consisting of a new two-layer unit-cell is proposed. In the proposed unit cell, a double cross slot ring (DCSR) is etched on a square patch which support feed angle variation up to 40°. The first layer of the antenna has 169 elements, whereas in the second layer the unit-cells in the fifth-ring are removed such that it has 144 elements, so the antenna has a non-uniform two-layer structure. The proposed non-uniform structure has wider gain bandwidth than the uniform structure. In order to confirm the simulation, a prototype of the antenna is manufactured and tested. The measured results reveal that the antenna has 31% (9.95–13.62 GHz), 41.4% (9.85–15 GHz) and 46% (9.48–15.15 GHz) gain bandwidth for the 1-dB, 2-dB, and 3-dB criterion, respectively. Additionally, the maximum gain of 21.64 dB at 10.6 GHz with an aperture efficiency of 27.45% is achieved. So, the proposed structure has broadband performance which is an appropriate choice for broadband applications in communication systems.