Phase correcting reflection zone plate for focusing microwave

摘要

A zone plate for focusing microwave energy is provided comprising a plurality of reflective portions corresponding to zones of the zone plate, each reflective portion reflecting energy &lgr;/P out of phase with respect to adjacent reflective portions, where &lgr; is the wavelength of the energy. The reflective portions are positioned in P parallel planes mounted on low dielectric loss sheets and separated by a distance of &lgr;/2P such that energy reflected from the reflective portions constructively interfere at a focus of the zone plate.