Intelligent wireless power transfer via a 2-bit compact reconfigurable transmissive-metasurface-based router.

With the rapid development of the Internet of Things, numerous devices have been deployed in complex environments for environmental monitoring and information transmission, which brings new power supply challenges. Wireless power transfer is a promising solution since it enables power delivery without cables, providing well-behaved flexibility for power supplies. Here we propose a compact wireless power transfer framework. The core components of the proposed framework include a plane-wave feeder and a transmissive 2-bit reconfigurable metasurface-based beam generator, which constitute a reconfigurable power router. The combined profile of the feeder and the beam generator is 0.8 wavelengths. In collaboration with a deep-learning-driven environment sensor, the router enables object detection and localization, and intelligent wireless power transfer to power-consuming targets, especially in dynamic multitarget environments. Experiments also show that the router is capable of simultaneous wireless power and information transfer. Due to the merits of low cost and compact size, the proposed framework may boost the commercialization of metasurface-based wireless power transfer routers.

Highly decorrelated multiplexing metasurface for simultaneous dual-wavelength and dual-polarization continuous phase manipulation.

Multiplexing metasurfaces have drawn great interest from the microwave to optical regimes. However, previous works often encounter the restriction of insufficient independence and deficient interference suppression among different channels. Herein, a metasurface platform featuring a dual-wavelength and dual-polarization multiplexing operation is proposed for highly decorrelated and completely independent manipulation of four frequency and polarization states. As illustrative examples, two paradigms of a multiplexing holographic metasurface in which four channels can respond independently without conjugate images are presented, and the measurement results not only validate the feasibility but also exhibit excellent imaging efficiency. The proposed metasurface may thus boost more complex and versatile multi-functional devices.

An efficiently-designed wideband single-metalens with high-efficiency and wide-angle focusing for passive millimeter-wave focal plane array imaging.

Wide-angle, high-efficiency, wide-band, and ultra-compact focusing blocks are crucial for implementation and future evolution of passive millimeter-wave focal plane array imaging systems. The spherical or doublet metalens can attain high-efficiency, wide-angle field-of-view (FOV) but suffer from fabrication difficulties, complex assembly, and low compactness. Here we present an efficient single-metalens design capable of performing high-efficiency diffraction-limited wideband focusing over a wide-angle FOV. This single-metalens design can greatly mitigate the Seidel aberrations by a rational allocation of amplitude-phase of the electromagnetic waves. A proof-of-concept metalens at millimeter-wave band (33 GHz-37 GHz) confirms the validity of our design.

Metagrating-enabled Brewster's angle for arbitrary polarized electromagnetic waves and its manipulation.

Brewster effect has attracted extensive interests through microwave to optical regime. However, previous work mainly focused on the cases with single linear polarization. We demonstrate in this paper an equal Brewster's angle for both TE (transverse-electric) and TM (transverse-magnetic) waves. Tunable Brewster effect is furthermore achieved. For practical implementation of this effect, we propose an anisotropic metagrating composed of modified split ring resonators (MSRR) as a proof-of-concept in X-band. Measurement results of the manufactured prototypes validate our method. The proposed metagrating featuring Brewster's angle manipulation potentially paves the way for many applications throughout the spectrum, e.g., angular selectivity.