DME operates in which frequency range?

DME operates in which frequency range?

• A. 108 to 118 MHz
• B. 960 to 1215 MHz
• C. 2.4 to 2.5 GHz
• D. 30 to 300 MHz

Answer: (B)

DME operates in the UHF band around 960 to 1215 MHz. This range is allocated for DME so the system can time the exchange of interrogation and reply signals between the ground station and the aircraft transponder, giving accurate distance information. Using UHF provides good line-of-sight transmission over typical air-to-ground distances and enough channel density to support many simultaneous interrogations without excessive interference. It also keeps DME separate from VOR/LOC navigation, which use the VHF band (108–118 MHz), and from common wireless bands like 2.4–2.5 GHz.

DME operates in the UHF band around 960 to 1215 MHz. This range is allocated for DME so the system can time the exchange of interrogation and reply signals between the ground station and the aircraft transponder, giving accurate distance information. Using UHF provides good line-of-sight transmission over typical air-to-ground distances and enough channel density to support many simultaneous interrogations without excessive interference. It also keeps DME separate from VOR/LOC navigation, which use the VHF band (108–118 MHz), and from common wireless bands like 2.4–2.5 GHz.