Which of the following is a use of UHF communications?

• A. Marine navigation beacons
• B. SATCOM, GPS, microwave links, radar, cell phones, WLAN, Bluetooth, satellite radio
• C. Acoustic underwater signaling
• D. Weather balloons telemetry

Answer: (B)

UHF communications span roughly 300 MHz to 3 GHz, which makes it ideal for line-of-sight links that balance antenna size, signal quality, and penetration through obstacles. That broad range supports many modern systems in one way or another: satellite communications—backhaul links and satellite radio—use bands that sit inside or near UHF; GPS signals lie in the L-band, which is within UHF, so GPS receivers operate in this same spectrum; radar systems often use frequencies in the UHF region; and common mobile and personal wireless technologies—cell phones, WLAN, and Bluetooth—operate at frequencies around 1–2.4 GHz, well inside UHF. Microwave backhaul also falls in this area, enabling high-capacity connections between networks. So, using UHF covers this wide set of applications, making it the best match for the described uses.

The other options point to signaling methods that rely on different bands or media: marine navigation beacons generally use the VHF maritime band; acoustic underwater signaling uses sound waves rather than radio waves; weather balloon telemetry can use various RF bands but isn’t as representative of the broad range typical of UHF communications.