Horn antennas are a type of directional antenna that consists of a flared metal structure. They are designed to radiate or receive electromagnetic waves efficiently, making them useful in various applications, including radar and satellite communications. The shape of the horn helps to focus the energy in a specific direction, enhancing the antenna's gain and directivity. These antennas can operate over a wide range of frequencies, depending on their design. Common types include the rectangular horn and cylindrical horn, each suited for different applications. Their simple construction and effectiveness make horn antennas popular in both research and practical uses.