What do the terms “L band” and “S band” specify?

The terms "L band" and "S band" are letter designations historically developed by the military for specific microwave frequency ranges. In amateur radio satellite operations, these letters are used as shorthand for particular bands. Specifically, "L band" roughly corresponds to frequencies around 1 to 2 GHz, which includes the amateur 23-centimeter band (1240-1300 MHz). "S band" covers roughly 2 to 4 GHz, which includes the amateur 13-centimeter band (2300-2450 MHz). Distractors mentioning 2 meters and 70 centimeters correspond to the VHF (V band) and UHF (U band) designations in satellite terminology, not L and S bands. Knowing these letter codes is essential for matching the correct uplink and downlink frequencies on microwave satellites.