metasignal

Metasignal is a term used in the field of metasurface engineering to describe a wave or signal that has been shaped, encoded, or manipulated by a metasurface or metamaterial. In this context, a metasurface is a planar arrangement of subwavelength scatterers that locally controls amplitude, phase, polarization, or spectral content of an incident wave. When a signal interacts with such a structure, the resulting waveform—after transmission, reflection, or scattering—can be described as a metasignal, reflecting the engineered transformation applied by the surface.

Metasignals are studied across optics, radio frequency, and acoustics, and may be static or reconfigurable. Reconfigurable metasurfaces use tunable unit cells (for example, varactors, MEMS switches, or phase-change materials) to dynamically alter the metasignal, enabling functions such as beam steering, focusing, lensing, holography, or polarization conversion. In theory, metasignals can be designed to implement complex wavefront operations in a compact, flat form factor, exploiting generalized laws of refraction and reflection defined by phase discontinuities at the metasurface.

Design and analysis typically rely on full-wave electromagnetic simulation, unit-cell characterization, and optimization to achieve the desired metasignal. Challenges include losses, bandwidth limitations, fabrication tolerances, and crosstalk between unit cells. Metasignal concepts are related to but distinct from traditional signal processing, representing a physical layer that pre- or post-processes the waveform via engineered materials.

Applications appear in imaging, communications, sensing, radar, and computational imaging, where metasignals enable programmable wavefront control and compact, adaptive devices. The term is used variably, and in some contexts may be described as metasurface-based signal processing or wavefront engineering.

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