Additively Manufactured Multi-Material Ultrathin Metasurfaces

CHALLENGE

While the use of metamaterials to control linearly polarized wavefronts has been well established, manipulating more geometrically complicated waves with circular polarization has so far proven more problematic.
In contrast to linear polarization, where waves are in the same plane, circular polarization often decouple waves into two opposite 3D helix-shaped paths, one spiraling clockwise, referred to as righthanded circular
polarization (RCP), and its counterpart counter-clockwise or lefthanded (LCP).

The upcoming wireless ecosystem will enable billions of high-speed wireless devices in a These more complex waveforms are of particular interest in research and development since they can carry more information and therefore can significantly increase the channel capacity of wireless communication networks, like 5G.
Using additively manufactured electronics (AME) fabrication technology to create the 3D ultrathin surfaces, Dr. Yang Yang’s group at the University of Technology Sydney (UTS) tested an experimental method to control the path of decoupled circular polarized microwaves while maintaining the informational integrity of their geometric phase.

The proposed ultrathin configuration cannot be easily achieved using conventional fabrication techniques such as printed circuit board (PCB) due to the assembling challenges.
The advantages of the multi-material additive manufacturing for LCP/RCP decoupled metasurface are low cost and fast prototyping.
The geometric phase-shifting is achieved by only rotating the transmitting antenna rather than in-plane rotating the whole unit cell.

Because the receiving antenna is linearly polarized, the metasurface can be further extended to folded-type metasurfaces. The proposed strategy has the potential to be used to implement other multifunctional devices for polarization beam splitters, Orbital Angular Momentum (OAM) communication, and holograms.

Further, miniaturized element frequency sensitive surface (MEFSS) low-volume manufacturing with AME opens up industry applications in acoustics, sensors, radar imaging, terahertz, and infrared optics, coatings, and films, lidar systems for self-driving cars, and medical imaging.