The Metasurface (MS) antenna is an important microwave component in communication system due to its unique beam radiation capability. However, current studies mainly pay attention to improving the performance of the main lobe of the MS antenna, leaving the side-lobe unexplored although it is also essential in some practical applications. In this work, several phase- and amplitude-control reflected MSs have been proposed to simultaneously manipulate the antenna’s main- and side-lobes. The MSs consist of modified I-shape particles which can independently manipulate the phases and amplitudes of the cross-polarization waves by changing the split-size and orientation, respectively. A focusing phase-distribution and different Taylor amplitude- distributions have been fixed on the MSs. By illuminating the MSs with a self-made antenna, we have successfully designed four MS antennas. For the first antenna, we solely pay attention to improving the main-lobe and achieve a high gain of 20.7 dB at 10GHz. For the other three antennas, we also aim to manipulate their side-lobes. The resultant side-lobe-levels are about -25 dB in xoz-plane for the second antenna and -29 dB in the yoz-plane for the third antenna and both of the former two characteristics for the fourth antenna. Compared with the first MS antenna, the last three antennas suffer from gain reductions of 2 dB, 1.7 dB and 3 dB respectively. These proposed MS antennas provide a new way to manipulate both main- and side-lobe levels and also greatly promote the integration of MSs and antennas.

The use of microstrip transmitarrays (TAs) and reflectarrays (RAs) is essential in long-range communication systems because of their high-gain radiations, narrow beam widths, simple configurations, and easy fabrication. We propose a novel antenna system that combines the functionalities of TAs and RAs. The antenna system consists of a specially designed bifunctional metalens and a self-made Vivaldi antenna (feed source). The metalens can focus the y-polarized incident wave at the transmission side and focus the x-polarized wave at the reflection side with the same focal length. By launching the metalens with differently polarized Vivaldi antennas, we were able to obtain a TA and RA. Moreover, the realized RA can deflect the radiation beam to a specified angle to avoid blockage of the feed antenna. Our numerical and experimental results coincided, indicating that the proposed antenna system demonstrated several improvements, including the ability to achieve multiradiation patterns, realize high gains, and adopt simple standard print circuit board technology. Our findings significantly expand the capabilities of metasurfaces in controlling electromagnetic waves and open up a new avenue for the design of high-performance multifunctional antenna systems and metadevices.

A novel triple-layer dual-mode meta-atom wherein an H-shaped structure is combined with a pair of symmetric patches is proposed. The composite structure substantially lowered the operation frequency, and balanced phase agility with transmission magnitude bandwidth. The transmission phase limit of the proposed composite structure approaches the theoretical limit. Because this structure has appealing features, we employed a set of these ultrathin meta-atoms to implement the phase distribution of an optimized array using the alternating projection method. An X-band single-feed quad-beam transmitarray consisting of 25×25 elements, each carefully designed to exhibit the desired transmission phase, was designed, simulated, physically implemented, and measured. Feeding the meta-array using a horn at its focus, four-beam radiation patterns with satisfactory sidelobe levels and gain were numerically and experimentally demonstrated. The peak gain was found to be 18.8 dB at 9.6 GHz, and the aperture efficiency was calculated as 38.3%. Moreover, the half-power beamwidth of the array antenna was approximately 7°, which was 50° narrower than that of a bare feed horn. Moreover, the gain of each beam was higher than 17 dB in all studied cases, which was at least 7 dB higher than that of a bare feed horn.

Achieving simultaneous control of the amplitude and phase of a metasurface, especially in transmission geometry, is very essential in modern photonic research. An alternative strategy for manipulating the transmissive amplitude and phase is proposed by using a three-layered element. Two outer orthogonal gratings of the element can determine the transmissive polarization while the center modified I-shaped particle achieves a high-efficiency linear polarization conversion. We can control the transmissive phase by modulating the gap size of the modified I-shaped structure, and manipulate the transmissive amplitude by rotating the structure. As a proof of concept, we design a fan-shaped beam metasurface by using a genetic algorithm to obtain the optimal phase and amplitude distributions. The results show that the metasurface can generate a flat top (azimuthal angle range is −40° to 40°) beam under rectangular coordinates within 9.1–10.9 GHz. Our findings offer possibilities to realize arbitrary beam shapes, which not only widen the areas for shaping a wavefront by metasurfaces, but also offer an economical and simple alternative for a beam-forming array antenna.

A broadband folded transmitarray antenna (FTA) with ultralow-profile, high-gain, and high polarization purity is proposed in this communication. It consists of a focusing metasurface (MS) with the function of reflecting and transmitting two orthogonal linear-polarized waves, a reflection-type linear polarization conversion MS, and an open waveguide as a feed. With elaborate design, a −3 dB gain bandwidth of 43.5% from 9 to 14 GHz, a peak gain of 23.5 dBi, and a maximum aperture efficiency of 32.8% are achieved. Meanwhile, the −20 dB cross-polarization level at the broadside direction covers the entire operating band. Furthermore, it is worth mentioning that the profile of the proposed FTA is reduced to about 1/3 of the focal length and the profile-to-diameter ratio is only 0.22. The significant promotions in performance indicate the remarkable application value in portable communication systems.