Date:

2025-04-30

Title of Paper:

Broadband abnormal reflection based on metal-backed gradient index liquid slab: an alternative to metasurfaces

Journal:

J. Phys. D: Appl. Phys

Summary:

We present an alternative method of introducing phase
discontinuity, and demonstrate the design, fabrication and characterization
of a thin abnormal-reflection slab using compound liquids in
sterolithography (SL) container. Normally incident electromagnetic waves
penetrate into the gradient index slab and then are reflected by the metallic
backing. Because gradient phase difference is produced on the thin slab
surface, propagation direction of the reflected beam is modulated. To obtain
the phase gradient, we mix two liquids with different permittivity, which
can realize a refraction index range 1.6~6.5. To load and separate liquids
with different refractive indexes, sterolithography technique is used to
fabricate the thin-walled container using photosensitive resin. We designed
and fabricated a sample which has a 30° abnormal reflection angle under
normal incidence and is with a thickness of 1/7 wavelength under 8.0GHz.
Broadband far-field patterns, as well as near-field map at the working
frequency, were simulated, theoretically discussed and experimentally
measured. The results verify abnormal reflection of the sample. Compared
with abnormal-reflection metasurfaces, the thin slab has a wider bandwidth
(the relative bandwidth is 50%) and weaker polarization dependence.

Co-author:

M. Feng, X. Tian* et al.

Volume:

48

Page Number:

245501

Translation or Not:

No

Date of Publication:

2015-04-15