Diverse electromagnetic (EM) responses of a programmable metasurface with a relatively large scale have been investigated, where multiple functionalities are obtained on the same surface. The unit cell in the metasurface is integrated with one PIN diode, and thus a binary coded phase is realized for a single polarization. Exploiting this anisotropic characteristic, reconfigurable polarization conversion is presented first. Then the dynamic scattering performance for two kinds of sources, i.e. a plane wave and a point source, is carefully elaborated. To tailor the scattering properties, genetic algorithm, normally based on binary coding, is coupled with the scattering pattern analysis to optimize the coding matrix. Besides, inverse fast Fourier transform (IFFT) technique is also introduced to expedite the optimization process of a large metasurface. Since the coding control of each unit cell allows a local and direct modulation of EM wave, various EM phenomena including anomalous reflection, diffusion, beam steering and beam forming are successfully demonstrated by both simulations and experiments. It is worthwhile to point out that a real-time switch among these functionalities is also achieved by using a field-programmable gate array (FPGA). All the results suggest that the proposed programmable metasurface has great potentials for future applications.

In this letter, a wide-beam (at two main planes) antenna is proposed. To broaden the 3-dB beam-width of the original antenna, a pair of parasitic patches with metallic vias is creatively arranged on either side of the original radiation patches. Based on the proposed antenna element, two linear phased arrays are fabricated and measured. Measured results reveal that the wide-angle scanning capability of both H-plane and E-plane arrays can be obtained. The scanning beam of the former can cover territories ranging from -90 to 90, with gain loss within 3dB (8GHz-11GHz). The scanning beam of the latter can cover territories ranging from -70 to 70, with gain loss of 3-5dB (8GHz-10GHz).

In this paper, a novel method to generate multiple orbital angular momentum (OAM) vortex beams is proposed using a 1-bit metasurface. Through carefully adjusting the phase shift of each element, mirror-symmetrical OAM vortex beams are generated in targeted directions by a 1-bit metasurface under plane-wave illumination. Moreover, the topological charges of the generated vortex beams are opposite. Based on this phenomenon, dual-beam, four-beam, and full-space OAM vortex waves are respectively studied and generated by conducting full-wave simulations. Finally, a prototype of the proposed metasurface is fabricated and measured in an anechoic chamber. The measurement results show that multiple OAM vortex beams are successfully generated and detected, verifying the effectiveness of the proposed method.

An ultrawide-angle frequency beam scanning leaky-wave antenna (LWA) with a high scanning rate based on spoof surface plasmon polaritons (SSPPs) waveguide is proposed in this communication. A row of elliptical patches is placed periodically near the SSPPs waveguide, which can shift the fundamental mode of SSPPs waveguide to the fast-wave region and radiate electromagnetic (EM) waves. The simulated results show that the proposed LWA achieves an ultrawide scanning angle range of 172° over a narrow operation bandwidth of 9.8–12.28 GHz, which implies a high scanning rate. The simulated average gain of the proposed LWA is 10.13 dBi and its average total efficiency is 75.35%. The proposed LWA is fabricated and measured. The measured scanning angle range is 167° in the frequency band of 9.9–12.25 GHz, and the measured average gain is 9.73 dBi. Good agreements between the simulated and measured results are obtained, validating the proposed design.

Metasurfaces trigger great interests due to their potential ability to manipulate the propagation of electromagnetic (EM) waves. Plenty of fascinating EM phenomena have been generated using metasurface. However, two defects are hindering their development. The first one is that most metasurfaces only perform a specific functionality once designed, which means they do not possess tunable properties. The second defect is that most of them work either in reflection mode or transmission mode, leaving half of the EM space completely unexplored. Therefore, it is challenging to design metasurface with tunability and entire-space working modes simultaneously. Here, a tunable metasuface is presented to solve these problems. The proposed metasurface element is a multilayer structure which can manipulate EM waves in the entire-space. Concurrently, PIN switches are loaded on each element which can dynamically control transmission and reflection phases. Thus some intriguing EM modulation functions in the entire-space are realized, such as beam forming, anomalous reflection and diffusion. Simulated and experimental results prove the tunable metasurface. The proposed metasurface offers a feasible strategy to design tunable metadevices and for other related practical applications.

A novel reconfigurable metasurface for multiple functions is designed and investigated. The lattice of the metasurface is proposed to realize integrated absorption and polarization rotation and named as polarization conversion absorber (PCA). Then, lattices are arranged together to realize a certain function. Due to the independence of each lattice, the metasurface can present different performance based on different arrangement principle. Magnitude, polarization and phase modulation can be presented by manually arranging metasurface with 6 × 6 lattices. Both simulations and measurements prove that the proposed method provides a simple, flexible and effective strategy for multifunctional metasurface design.