Symmetrical microwave lenses

In recent years, considerable effort has been devoted to the development of lenses for use as focusing objectives with primary microwave radiators. This paper demonstrates a geometrical optics analysis of a double-convex, solid dielectric lens and two types of variable index lenses useful in microwave applications. Each of the three lenses is symmetrical with respect to a reference plane. Because of this symmetry, the lenses focus incoming waves from either side of the reference plane, so that a single focusing objective can be used with more than one feed. Design equations and construction information are given along with experimental results.