High-Efficiency Metasurface Emitters for Generating Arbitrarily Polarized Spatial Propagating Waves

Polarization plays an important role in practical applications, and hence it is an essential task to generate the desired polarization of a spatial propagating wave (SPW). Here, the authors propose a method to design radiation metasurface, or metasurface emitter, which can produce arbitrarily polarized SPW. Different from the conventional transmission and reflection metasurfaces that can only manipulate the incoming spatial wave, the proposed radiation metasurface can be regarded as an electromagnetic (EM) wave emitter that can generate SPW by itself. More importantly, the polarization of the generated SPW can be flexibly customized by designing the phase distribution on metasurface. The metasurface is fed by a monopole antenna, and the energy is first coupled into the metasurface to form a surface wave. Modulated by the metasurface, the surface wave is then converted into SPW. As a proof of concept, they design and fabricate the radiation metasurfaces that are capable of generating radially, azimuthally, linearly, and circularly polarized SPWs, as well as dual-beam radiations with different polarizations, respectively. The measured results have a good match to the theoretical predictions and full-wave simulations. The proposed method provides an efficient way to generate SPWs with any desired polarizations for easy integration.

Automated summary

The study presents a method to design radiation metasurfaces that can generate spatial propagating waves with arbitrary polarizations. By customizing the phase distribution on the metasurface, the polarization of the generated SPW can be flexibly controlled.