Automatic Design of Broadband Gradient Index Metamaterial Lens for Gain Enhance- Ment of Circularly Polarized Antennas

A broadband gradient index (GRIN) metamaterial lens for gain enhancement of circularly polarized antennas has been automatically designed, fabricated and investigated. The GRIN metamaterial lens consists of an isotropic dielectric plate with a corresponding distribution of deep-subwavelength drill holes each with the same diameter. Such drill holes have a negligible influence on both the polarization state and the spectral response of the electromagnetic wave transmitting through the resulting GRIN metamaterial lens. Therefore, the GRIN metamaterial lens is polarization-insensitive and can efficiently transform spherical waves into planar waves over a very broad frequency range keeping the initial polarization states (e.g., linear or circular) scarcely changed. In the following we have derived analytical formulas that enable the setup of distribution rules Received 11 May 2013, Accepted 31 May 2013, Scheduled 7 July 2013 * Corresponding author: Fan-Yi Meng ([email protected]).