Which frequency range is associated with Extremely High Frequency communications?

Which frequency range is associated with Extremely High Frequency communications?

• A. 3-30 GHz
• B. 30-300 GHz
• C. 30-300 MHz
• D. 0.3-3 GHz

Answer: (B)

Extremely High Frequency refers to the portion of the spectrum from about 30 GHz up to 300 GHz. This puts it above the SHF band (3–30 GHz) and into the millimeter-wave region, with wavelengths roughly 1 cm to 1 mm. Because of the high frequency, signals experience significant free-space loss and typically require line-of-sight paths and precise pointing, but they support very high data rates. Atmospheric absorption, especially around certain frequencies like 60 GHz, also shapes how this band is used, often for short-range, high-capacity links and some radar or satellite applications. The option that matches 30–300 GHz is the correct one. The other ranges correspond to different bands: 3–30 GHz is the SHF range, 30–300 MHz is the VHF range, and 0.3–3 GHz is the UHF range.

Extremely High Frequency refers to the portion of the spectrum from about 30 GHz up to 300 GHz. This puts it above the SHF band (3–30 GHz) and into the millimeter-wave region, with wavelengths roughly 1 cm to 1 mm. Because of the high frequency, signals experience significant free-space loss and typically require line-of-sight paths and precise pointing, but they support very high data rates. Atmospheric absorption, especially around certain frequencies like 60 GHz, also shapes how this band is used, often for short-range, high-capacity links and some radar or satellite applications.

The option that matches 30–300 GHz is the correct one. The other ranges correspond to different bands: 3–30 GHz is the SHF range, 30–300 MHz is the VHF range, and 0.3–3 GHz is the UHF range.