Microwaves are a form of
electromagnetic radiation with
wavelengths ranging from one meter to one millimeter; with
frequencies between and . This broad definition includes both
UHF and
EHF (
millimeter waves), and various sources use different boundaries. In all cases, microwave includes the entire
SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum, with
RF engineering often restricting the range between 1 and 100 GHz (300 and 3 mm).