title: Broadband microwave Luneburg lens made of gradient index metamaterials.
abstract: Luneburg lenses are able to form perfect focus that is free of aberration. Because of the varying refractive index throughout the lens, incoming electromagnetic waves can travel in a curved path and be guided to focus at the back of the lens. The implementation of Luneburg lenses is often difficult due to the challenges in creating a medium with varying refractive index using normal materials. This problem can be overcome with the use of gradient index metamaterials. We report a two dimensional Luneburg lens made of gradient index metamaterials. It consists of 17 concentric shells with etched patterns on a printed circuit board working in microwave X band frequency. The broad properties of the Luneburg lens are then discussed.
authors.affiliation: Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore. yuling.loo@gmail.com
authors.forename: Yoke Leng
authors.initials: YL
authors.lastname: Loo
authors.forename: Yarong
authors.initials: Y
authors.lastname: Yang
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Yun Gui
authors.initials: YG
authors.lastname: Ma
authors.forename: Chong Kim
authors.initials: CK
authors.lastname: Ong