Symphotic Multiplexing Medium at Microwave Frequencies

Abstract

As opposed to metasurfaces, which can produce a single output waveform in response to a single input waveform, volumetric metamaterials have the ability to perform independent functions on many distinct input waveforms. Here, we present an experimental demonstration of this multiplexing capability using a volumetric metamaterial designed using the symphotic method, which realizes highly efficient multiplexing structures in the strong scattering limit. In contrast to perturbative design methods such as volume holography that are only applicable in weakly scattering media, we provide a comprehensive approach that takes into consideration design and fabrication constraints and that can be verified in simulations. We then demonstrate an experimental realization of a symphotic device operating at a frequency of 10 GHz, which has been optimized for three distinct input waveforms corresponding to three distinct output waveforms. The device is realized using a low-loss three-dimensionally printed material. The symphotic device consists of a lattice of dielectric cylindrical elements with varying radii, excited in a parallel-plate waveguide to enforce two-dimensional field symmetry. The experimental results show excellent agreement with analytical coupled-dipole-method simulations and finite-element simulations. The experiments further demonstrate the scalability of symphotic metamaterials and their viability for advanced rf and optical devices.