The past few years have witnessed the great success of graphene in controlling the electromagnetic (EM) wave. As an important topic in both the physics and engineering fields, wavefront control has attracted more and more attention from the researchers. So far, most graphene-based wavefront control is studied in terahertz or higher frequencies. In the microwave band, relevant work is rarely reported, which is limited by the nearly purely resistive property of graphene, the lack of reactance makes phase control a difficult problem. In this paper, we present and experimentally realize the microwave programmable graphene metasurface (MPGM) for the first time. By analyzing the equivalent impedance, the necessary condition of achieving a binary element using resistive material is first derived. Inspired by which, the proposed structure can realize uniform reflection amplitude and opposite phase simultaneously through changing the voltage applied to graphene. Meanwhile, the patterned configuration makes it possible to control different elements independently. As a result, both simulated and measured results indicate that our MPGM can realize multiple functions such as beam redirecting and radar cross section reduction, paving the way for graphene in the application of designing tunable phase-based devices in the microwave band.

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Flexible and tunable radar absorbers (RAs) are in great demand both in stealth technologies and electromagnetic delusion for concealment of complex targets such as aircraft and unmanned aerial vehicle from radar detection. As a general approach, conventional lumped components such as varactor diodes and resistors are employed to achieve frequency and/or amplitude tunability of RAs. However, despite the intricate feeding networks and complex fabrication processes, this approach shows great difficulty in integrating the conventional rigid components with flexible substrate. Hence, it is an enormous challenge to realize both dual‐tunable and flexible RAs. Here the authors for the first time design and experimentally characterize a flexible and dual‐tunable RA with independent control of the frequency and amplitude. Most important is that the achieving both amplitude and frequency control is fully based on the tunability of graphene, without any lumped devices and intricate feeding network, and even without any metal involved. Hence, this dual‐tunable RA shows the priority of being flexible, light weight, and environmentally friendly. Although the prototype in this work is operating in microwave spectrum, the tunable functionalities at millimeter or terahertz spectral bands can also be obtained due to the intrinsic tunability of graphene.

A microwave filter is important to determine the performance of a wearable communication system. However, the materials used in existing microwave filters require sophisticated and expensive fabrication processes. Moreover, they are not compatible with flexible and wearable platforms. In this study, a novel strategy for realizing a tunable fabric microwave filter (TFMF) by taking advantage of the spoof surface plasmon polariton (SSPP) structure and using organic electrochemical transistors (OECTs) is presented, which are lightweight and exhibit excellent mechanical flexibility and deformability. The TFMF is manufactured using fabric materials, and the OECT is printed to serve as a state‐changing material. The developed TFMF exhibits excellent flexibility, high planar integration and improved wearing comfort. Furthermore, the operating frequency of the TFMF with well‐designed gradient structures and multi‐state dispersion characteristics can be effectively tuned by applying different voltage sequences. To the best of the authors’ knowledge, this is the first tunable microwave filter designed for use in wearable systems. The measurements of scattering parameters and data transmission with a communication system based on the TFMF demonstrate a feasible pathway for enhancing the performance of wearable wireless communication systems.

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