One-Sixteenth Spherical Homogeneous Dielectric Lens Antenna on Metal Corner Reflector for High-Gain Radiation With Size Reduction

In this letter, a three-dimensionally printed one-sixteenth fractional spherical homogeneous dielectric lens antenna on a metallic corner reflector is designed. This lens antenna is fed by an open-ended rectangular waveguide for high-gain radiation. The main design concept is to produce an equivalent spherical dielectric lens that is excited by multiple virtual sources arising from the multiple images of the original feed by the corner reflector's walls. Thus, the antenna can retain a compact size with a sufficiently effective aperture to produce a higher radiation gain. In particular, a ray-tracing method of geometrical optics is introduced for easily determining the proper sizes of the corner reflector's walls, which leads the proposed work to be more efficient than using a full-wave simulation. The superiority of the antenna is validated by examining a practical design for a radar system at 9 GHz band. It is found that the optimum dielectric constant (ε
_r
), ground plane size, and effective aperture area, relatively speaking, depend on the radius of the lens's sphere. This proposed antenna well suits multifeed satellite communication antennas, radar, and other high-gain antennas applications.