A Luneberg-lens update

Some proposed satellite-based mobile communication systems require multibeam systems at millimeter-wave frequencies. This is a primary factor in the renewed interest in Luneberg lenses. Luneberg (1944) lenses prove useful in a variety of antenna and scattering applications. In antenna applications, their chief advantages are an ability to form multiple beams that may point in arbitrary directions, and their broadband behavior. Lens weight, and complexities involved in manufacturing such lenses, remain their primary drawbacks. Unfortunately, no significant advances in the fabrication techniques have come to pass in forty years. However, operation at millimeter-wave frequencies makes the lens weight inconsequential. The vast majority of the research on spherical lenses took place before computers were commonplace in antenna design. The author reviews some of the applications of Luneberg lenses, and adds some more recent data, generated using a numerical model