Matching layer design to improve the performance of an inhomogeneous dielectric flat lens at millimeter-wave frequencies

In this paper, the design of a matching layer to increase the maximum achievable gain, reduce the back-radiation, and enhance the bandwidth performance of a dielectric flat lens antenna for millimeter-wave applications is presented. The performance of the original inhomogeneous gradient-index dielectric flat lens is compared with the performance of the lens with an inhomogeneous matching layer design. Our numerical results indicate that compared to the original flat lens design without matching layer, the lens with the matching layer delivers a better performance in terms of maximum achievable gain, back-radiation reduction, and bandwidth.