This book highlights the fundamentals and practical methods of metamaterials-based optical and radio frequency sensing. Combined with engineering practices, the book illustrates in detail wide frequency electromagnetic signal cloaking and the detection behavior of metasurfaces, including the structure of metasurfaces, electric-controlled behaviors, layout design and fabrication methods, and related experiment results. This book is expected to inspire the research and development of new optical and radio frequency detectors. It is suitable for researchers and engineers working on semiconductor devices, applied optics, and wide frequency signal detection. It is also a good reference for students in these areas.