What type of transmission is primarily used in the ultra high frequency band?

In the ultra high frequency (UHF) band, direct waves are the primary mode of transmission. This is because UHF frequencies, which range from 300 MHz to 3 GHz, have wavelengths that allow for line-of-sight communication. Direct waves travel in straight lines from the transmitting antenna to the receiving antenna without being reflected or refracted by the atmosphere or the ground. This characteristic makes UHF particularly suitable for applications such as television broadcasting, mobile communications, and two-way radio systems.

Ground waves are more prominent at lower frequencies, while sky waves, which rely on ionospheric reflection, are typical of high frequency (HF) bands. Reflected waves can occur, but they are not the primary mode in the UHF range due to the line-of-sight nature of direct wave propagation at these frequencies. Therefore, the emphasis on direct waves in the UHF band is crucial for reliable communication in various modern technologies.