Dual-Band Fresnel Zone Plate Antenna With Independently Steerable Beams

Fresnel zone plate (FZP) antennas can implement steerable beams based on reconfigurable binary-amplitude diffractive patterns. Because of this unique characteristic, FZP antennas have concise architectures compared with phased array systems. So far, FZP antennas can only support a single frequency band. This is because only one diffractive pattern can exist on the aperture at a given time. In this communication, we demonstrate a dual-band FZP antenna with two independent coexistent diffractive patterns. Implemented based on multiple pairs of electrically induced opacity and transparency, such diffractive patterns can be independently configured by binary direct current (dc) voltages. Simulation and experimental results validated the theoretical analysis. The proposed method can be extended to obtain triple-band FZP antennas, playing important roles in a wide range of potential applications.