A Double-Layer Highly Efficient and Wideband Transmitarray Antenna

A double-layer highly efficient and wideband transmitarray antenna is presented. The transmitarray element is composed of four metal vias and two crosspatches with two stubs. The metal vias penetrate the entire substrate and arrange symmetrically. The crosspatches are printed on both sides of the dielectric substrate. The metal vias are introduced to enhance the coupling strength. The stubs are added to ensure a sufficient phase shift range. The achievable transmission magnitude is greater than -2 dB, and the phase shift range exceeds 360° within the whole band. A transmitarray antenna using the proposed element was designed, manufactured, and measured. The simulation and measurement results are in good agreement. The measured maximum gain is 29.2 dBi at 18 GHz with the 51.4% aperture efficiency. The experimental results show that the proposed antenna has a 1-dB gain bandwidth of 9% (17.2-18.8 GHz). The proposed double-layer transmittarray antenna realizes the low-profile characteristic, simplifies the design complexity, and solves the problems of the mass and the cost.