Frequency-tunable high-efficiency retroreflection from a magnetically biased ferrite metagrating
Year: 2026
Type: article
Abstract: Retroreflection is critical for localization, sensing, and wireless communication. Though the conventional 3D retroreflectors, gratings, and metasurfaces are applied to achieve retroreflection, the reconfiguration of operating frequency is still a challenge. Here, we demonstrate a high-efficiency retroreflector whose operating frequency can be reconfigured without any structural modification. The device consists of a magnetic metagrating backed by a metal plate, where the unit cell of the metagrating is a ring of yttrium-iron-garnet (YIG) ferrite rods. Simulation demonstrated the retroreflector could continuously tune working frequency with efficiency 95% over a frequency range 210 MHz (9.90-10.11 GHz) by varying the applied DC bias field. We revealed that the retroreflection arises from coherent multiple scattering between the metagrating and the backplate, and its frequency is set by the bias-field-dependent anisotropic permeability of the ferrite. Experimental measurements in a parallel-plate waveguide confirm both the high retroreflection efficiency and the frequency tunability of the designed retroreflector. This work establishes a simple, structurally invariant route to tunable retroreflection.
Source: Optics Express
DOI: 10.1364/oe.614816
Institution: Nanjing University
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,270
OpenAlex ID: W7220935018