The feasibility of Luneberg lenses for 20-30 GHz applications

The coverage/gain requirements of several future satellite MM-wave communication systems can most efficiently be met by multi-beam antennas. (MBA) using spherical lenses. There are two types of spherical lenses: the "constant K" or uniform dielectric constant sphere and the generalized Luneberg lens where the dielectric constant varies as a function of the lens radius (gradient index lens). Being spherically symmetric, both lenses can provide a wide area coverage without any scan loss or beam pattern degradation. These types of MBA/lens systems are almost always bypassed or eliminated from consideration by the system designers because there is little or no data on practical implementations. This is especially true for the Luneberg lens. This paper describe the current understanding of these lenses and the enabling technologies which make them feasible for MM-wave applications.