Lband

L-band is a designation for a portion of the radio spectrum, typically defined as frequencies from about 1 to 2 gigahertz (GHz). In ITU-R naming, this band sits between the lower microwave bands and higher-frequency bands, and it covers wavelengths roughly from 0.15 to 0.30 meters. The exact allocations within 1–2 GHz vary by country, but the general range is used worldwide for a variety of civil, commercial, and military systems.

The band is known for its balance of propagation characteristics and available bandwidth. It experiences relatively modest atmospheric attenuation, making it suitable for spaceborne and ground-based links over long distances. Antennas in this band are smaller than those required at higher frequencies, and the signals can penetrate foliage and light weather better than many higher bands, though they still suffer some rain attenuation under heavy precipitation.

Major applications include satellite communications (mobile satellite services and certain fixed-satellite services), and navigation and timing systems. L-band carries many GNSS signals, with civilian and military transmissions around roughly 1.2–1.6 GHz. Notable examples include GPS signals such as L1 at 1575.42 MHz and L2 at 1227.60 MHz, as well as L-band signals used by Galileo and GLONASS. Satellite networks such as Iridium and many maritime aviation services also operate in or near the L-band, including the Inmarsat and other MSS services around 1.5–1.6 GHz.

Radar systems also use L-band for surveillance and ranging, including some air traffic control and military radars. The secondary surveillance radar uses 1030 and 1090 MHz, positions within the L-band, illustrating practical uses in aviation.

Regulatory oversight is provided by ITU-R and national regulators, with spectrum sharing and licensing to manage interference and allocate services.