Broadband planar Luneburg lens based on complementary metamaterials

摘要

A two-dimensional broadband low-loss Luneburg lens has been designed based on the complementary metamaterials. The complementary I-shaped unit has been chosen as the basic cell due to its high resonant frequency, whose effective constitutive parameters are nearly constants at low frequencies. Numerical simulations are performed to determine the relationship between the unit geometry and the refraction index. The experimental sample has been fabricated and tested in a two-dimensional near-field microwave scanning apparatus, where the experiment and simulation results agree very well. Good focusing ability has been shown from the measured field distributions of the designed planar Luneburg lens.