A Kirigami-Inspired Foldable Spherical Fully Dielectric Luneburg Lens Antenna

A kirigami-inspired foldable spherical fully dielectric Luneburg lens antenna using additive manufacturing technology is presented for the first time. The proposed lens is discretized into multilayer spherical shells which are subdivided by several interlaced annular dielectric sheets with different notch densities. The existence of the flexible notches and the different notch densities in different layers realize the structural foldability and the gradient distribution of the Luneburg lens, respectively. The foldable Luneburg lens in the unfolded state is fed by a horn antenna and the measured results reveal that the proposed antenna with different feed incidence angles has the reflection coefficients better than -10 dB in the entire Ku band, gains varying between 15.2 and 18.7 dBi, and symmetric radiation patterns with narrow beamwidths.