Matched and wideband flat lens antennas using symmetric graded dielectrics

Matched and wideband flat lens antennas using a two-dimensional symmetric graded dielectric (SGD) are considered. An explicit relation for refractive index of this type of antenna is presented. This design relation is obtained in two steps. The variations of refractive index are determined first in the radial direction and then in the axial direction. Additionally, reflector-lens antennas are introduced using two-dimensional SGD. The validity of design methodology is verified by simulation.