Flat Fully Metallic Luneburg Lens Antenna for Millimeter-Wave Communication

A flat fully metallic Luneburg lens antenna working at millimeter-wave (MMW) band is presented in this paper. By using the principles of transformation optics (TO), the cylindrical Luneburg lens is modified to the flat lens form, allowing for a reduced volume. The standard waveguide WR22 is employed to feed the lens, due to its simple structure and stable performance. The simulated results show that the proposed lens antenna can operate over $35 \sim 45 \mathrm{GHz}$ with a maximum aperture efficiency of $65 \%$, as well as the gain of 15.8 dBi. Meanwhile, the proposed lens antenna can achieve a multi-beam scanning by moving the feed along the horizontal plane and a wide beam coverage in the vertical plane. Thus, the presented lens antenna is much suitable for MMW communication and other application field.