Low-Cost and Purely Passive Reflective Metasurface Using Modular Meta-Strip for Indoor Sub-6-GHz Communication

Reflective metasurfaces (RMSs) using electrically controlled methods are attracting considerable attention for their potential to improve coverage in shadowing areas that will be encountered in next-generation wireless communications. In general, each unit cell integrates with an electrical control device such as positive-intrinsic–negative (PIN) diodes or varactors. Because of the electrical devices, the manufacturing cost is high, and the RMS consumes dc power; however, cost and power consumption are less than those of repeaters. In this article, we propose a novel low-cost and purely passive modular RMS (MRMS). Instead of electrical control devices, four kinds of modular meta-strips are introduced. The proposed MRMS is capable of manually programming modular meta-strips to produce general reflections, anomalous reflections from 0° to 50°, and scattering. The proposed MRMS can be reassembled with the desired functionality. The performance of the proposed MRMS is demonstrated through theoretical and numerical analysis, continuous-wave and digital signal measurements, and indoor communication scenario measurements. Although the proposed MRMS cannot be programmed dynamically, it can simply be customized to maintain wireless connectivity of the Internet-of-Things (IoT) devices, which are not frequently moved.