Abstract: A radio frequency antenna array uses lenses and RF elements, to provide ground-based coverage for cellular communication. The antenna array can include two spherical lenses, where each spherical lens has at least two associated RF elements. Each of the RF elements associated with a given lens produces an output beam with an output area. Each lens is positioned with the other lenses in a staggered arrangement. The antenna includes a control mechanism configured to enable a user to move the RF elements along their respective tracks, and automatically phase compensate the output beams produced by the RF elements based on the relative distance between the RF elements.

Abstract: The invention is directed to a novel foil for use as an entrance window foil during the production of [18F] by irradiation of [18O] using a particle accelerator. The foil is a high strength cobalt based alloy foil, thin film coated with an inert and refractory metal such as niobium.