The full-wave spectral domain analysis is a powerful theoretical tool for the study of layered Fresnel zone plate (FZP) structures, including multilayer plates and/or substrates. The double-layer FZP lens is a reasonable scheme to replace the FZP reflector in applications where a flat antenna profile is required; and a four-layer FZP lens is more attractive in performance. The key parameter in FZP lens design is the spacing between the plates. However, a rigorous calculation of radiation patterns for multilayer FZP lens antennas is still a target of further study.