title: Electromagnetic field attractor made of gradient index metamaterials.
abstract: We present a device that is designed with varying permittivity ε(r) such that an electromagnetic wave in the K-band of the microwave regime entering it will bend inward towards the core. The core is made of silicon composites. We follow the distribution formula of the permittivity for the device derived by Narimanov and Kildishev using the optical-mechanical analogy. The diameter of the device is 14 cm, and it is constructed out of 21 rings of two different types of etched printed circuit boards, as well as dielectric powders as adding filling materials. The experimental wave intensity profile, based on parallel plate measurements for the cases where the incident plane wave is slightly displaced to the top of the center of the device and the case of on center incidence, are presented and discussed. In spite of some mismatch of the core and metamaterial structures of the device found, approximately 80% of the wave still manages to reach the core of the device and gets trapped and absorbed. Broadband properties of the device are also investigated.
authors.affiliation: Center for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore, Singapore.
authors.forename: Yarong
authors.initials: Y
authors.lastname: Yang
authors.forename: Loo Yoke
authors.initials: LY
authors.lastname: Leng
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Yungui
authors.initials: Y
authors.lastname: Ma
authors.forename: C K
authors.initials: CK
authors.lastname: Ong