The concept of dual-polarized reconfigurable reflectarray (RRA) featuring dual-polarized beam control is proposed and demonstrated using a dual-channel programmable metasurface. The p-i-n diodes are incorporated into each metasurface element as the active components to provide independent phase control in two orthogonal polarization channels. By altering the working states of each p-i-n diode, well-defined beam scanning can be obtained. Element design, focal diameter ratio selection, and discretized phase distributions are carefully optimized to ensure stable radiation performance of the proposed RRA. As verification, a prototype consisting of 20 $\times20$ elements is fabricated and measured, which is controlled by a field programmable gate array-based controller. Measured results show that wide-angle beam scanning up to ±40° can be obtained around 7.45 GHz, with peak gains of 21.13 and 20.89 dBi in dual channels, corresponding to aperture efficiencies of 16.35% and 15.47%. The proposed dual-polarized RRA brings a new freedom in polarization manipulations for versatile beam scanning, which provides promising applications in wireless communication and tracking/detecting systems.

Active metasurfaces pave a way for manipulating electromagnetic (EM) waves in real-time by incorporating with tunable materials or components, emerging as an attractive solution to achieve versatile EM functionalities in dynamic fashions. However, most of the active metasurfaces demonstrated so far only support tunable responses for a certain single frequency band, or have obvious frequency cross-talks that cannot provide dual-band independent operations, limiting their further uses in practical applications. Here, we propose a 1-bit high-efficiency programmable metasurface to achieve completely independent functions with real-time reconfigurability controlled by FPGA hardware system in both C-band and X-band. Specifically, the metasurface is designed with abilities of generating multi-beams or twin-beam scanning in the low frequency band while dynamic beam-scanning in high frequency band. As the experimental verifications, a double-layered metasurface has been fabricated and tested, and the measured results agree well with the simulations, demonstrating its abilities of independent, high-efficiency, real-time, and programmable manipulation of EM waves in two discrete frequency bands. The proposed concept may largely enhance the information capacity of the metasurface, bringing new degrees of freedom in achieving versatile tunable functionalities and offering useful applications in the radar and wireless communication systems.

Metasurface retroreflectors, which scatter the incident electromagnetic wave back to incoming direction, have received significant attention due to their compelling advantages of low profile and light weight compared with conventional bulky retroreflection devices. However, the current metasurface retroreflectors still have limitations in wide‐angle and omnidirectional operations. This work proposes a high‐efficiency, wide‐angle, reconfigurable, and omnidirectional retroreflector composed of spin‐locked phase gradient metasurface with a thickness of only 5.2 mm or 0.07 operating wavelength. The reflection phase of constituent meta‐atoms can be controlled dynamically and continuously by altering their orientation states through individually addressing each mechanically rotational meta‐atom, whereas the reflection handedness is kept the same as incidence. Therefore, adaptive and arbitrary momentum can be imparted to the incident wave, providing high‐efficiency retroreflection over a wide continuous range from −47° to 47°. Moreover, such high‐performance retroreflection is extended to omnidirectional level, enabling great degrees of freedom that are unavailable by previous researches. As a proof of concept, a retroreflective metasurface is fabricated and experimentally demonstrated at microwave frequencies. The proposed thin thickness, high efficiency, and reconfigurable metasurface retroreflector can be extended to other frequencies that may offer an untapped platform toward reconfigurable spin‐based retroreflection devices for electromagnetic signal processing.

In this letter, an anisotropic metasurface is proposed for independent phase control upon orthogonal linearly-polarized waves, and is then applied to implement a low-profile wideband dual-polarized reflectarray antenna (RA) operating in Ku-band by integrating the metasurface with two Vivaldi feed sources. This RA can collimate both primary beams into one narrow beam along broadside direction with dual-linear polarizations or circular polarization. The prototype is fabricated and the measured results indicate that it achieves peak gain of 24.5 dBi, peak aperture efficiency of 37.4%, 1-dB gain bandwidth of 15% for fixed broadside direction for both Vivaldi feed sources. The proposed method may have potential uses in applications of the multiplexing, demultiplexing, and full-duplex antennas.