What is a Yagi antenna primarily used for?

A Yagi antenna is primarily used for communications in the frequency band of 10 MHz to UHF, which is why this option is the correct answer. This type of antenna is characterized by its directional nature and is commonly employed in various applications, including television reception and ham radio. Its design allows it to focus energy in a specific direction, making it efficient at receiving and transmitting signals in a range of frequencies that align well with the characteristics of UHF and other high-frequency bands.

The Yagi antenna's structure, which typically includes a driven element, a reflector, and one or more directors, enhances its gain and directivity in the specified frequency range. This capability is instrumental for applications that require clear and reliable communication over longer distances, especially in radio frequency applications.

While the other options touch on various forms of communication and use different types of antennas, they do not align as directly with the primary function of a Yagi antenna within its established operational frequency range. For instance, the use of Yagi antennas for satellite communications (as suggested in one option) is less common due to different requirements for satellite signal reception and transit.