Phased Hemispherical Lens Antenna for 1-D Wide-Angle Beam Scanning

A $Ka$ -band hemispherical lens antenna fed by a phased array antenna (PAA) for 1-D wide-angle beam scanning is presented. The hemispherical lens antenna with two dielectric layers is designed based on the combination of geometrical optics (GOs) and finite-element method (FEM), thus the computational complexity can be reduced without loss of accuracy. A modification procedure is then proposed to efficiently modify the lens antenna for wide-angle scanning property. Finally, the lens is fabricated through 3-D printing technology in spite of its complex shapes. A linear patch array is employed to feed the hemispherical lens antenna. By utilizing the conjugate field matching (CFM) method, the proposed lens antenna is able to achieve 1-D beam scanning with about 2.6 dB/5 dB gain loss as scanning to ±45°/60°. The measured results show that the proposed lens antenna has a low profile with a focus-to-diameter ratio (F/D) of only 0.14, and aperture efficiency for the on-axis beam is 52% at 27.3 GHz. The proposed antenna is highly suitable for 5G mm-wave wireless communication with the advantages of wide-angle beam scanning, low cost, and ease of fabrication.