Metallic waveguides are structures that guide electromagnetic waves along their length using metal materials. They are commonly used in high-frequency communications systems, radar systems, and other applications where low signal loss and high signal fidelity are important. Metallic waveguides are often made from materials such as copper, aluminum, or other conductive metals, and can be designed in a variety of shapes and sizes depending on the specific application. They are typically used in situations where traditional dielectric waveguides may not be suitable, such as in high-power applications or at higher frequencies. Metallic waveguides offer low signal loss, high power handling capability, and the ability to guide electromagnetic waves over long distances with minimal interference.