Transmission-line lens antenna with embedded source

We demonstrate how the recently proposed approach to create artificial ldquomaterialsrdquo with so-called transmission-line networks can be used in microwave lens antenna design. A two-dimensional transmission-line network is designed in such a way that wave propagation inside the network is nearly isotropic, and furthermore, the network is well coupled to the surrounding medium, which in this case is free space. Using the well-known equations for dielectric lens design, we choose the profile of our transmission-line lens in such a way that a line source placed inside the lens creates a plane-wave field outside the lens. Therefore the lens, excited with an embedded source, acts as a highly directive antenna.