Artificial microwave volume holograms based on printed dielectrics: Theory, performance analysis and potential application in antenna systems

Abstract

A new type of complex electromagnetic structure, the artificial microwave volume hologram (AMVH), has been studied systematically. The structure consists of cascaded planar lattices of metallic circular patches with varying size and can be designed to have an effective dielectric modulation that follows a holographic interference pattern. Under the illumination of certain electromagnetic waves, an AMVH can reproduce a required wave field pattern based on its design, just like a traditional volume hologram in optical holography. A theoretical model, namely the self-consistent dynamic-dipole interaction theory (DDIT), has been developed to characterize AMVHs for wave scattering and beam form conversion. It can also be used for designing AMVHs as well as for optimization. Multiplex AMVHs have been proposed and simulated, in which more than two wave beams interact with the structure, which results in wave beam conversion, splitting or combining. Their flexibility and application potential are illustrated through a number of examples such as multi-beam antennas, shared apertures, and beam splitting and combining. Experimental validation of the theory has been carried out on several fabricated AMVHs, which has confirmed the theory. An alternative patch geometry, namely a square patch, has been proposed and analyzed for application in AMVHs, which can provide significant higher electric polarizability. Finally, a full-wave FEM simulation has been done to verify the accuracy of the theoretical model.