microwavespectrum

Microwave spectrum refers to the portion of the electromagnetic spectrum occupied by microwaves, typically defined as about 1 to 300 gigahertz, corresponding to wavelengths from 30 centimeters to 1 millimeter. Some sources extend the term into the hundreds of megahertz, but the microwave range is commonly associated with higher-frequency bands used for line-of-sight communications and sensing.

Propagation in the microwave range is strongly influenced by atmospheric conditions and path geometry. The atmosphere has absorption features from oxygen near 60 GHz and water vapor near 183 GHz, creating windows of reduced attenuation at other frequencies. Higher-frequency microwaves, often called millimeter waves, enable very high data rates but require clearer line-of-sight and shorter link distances, while lower microwave bands can support longer-range links in fair weather.

Applications include radar, satellite and terrestrial point-to-point links, wireless backhaul for cellular networks, and various consumer and industrial uses in the unlicensed and licensed bands. The microwave region also includes common household uses such as microwave ovens operating at 2.45 GHz, part of the ISM bands. The millimeter-wave portion (roughly 30–300 GHz) is central to recent developments in high-capacity wireless backhaul and emerging 5G/6G technologies, with bands around 28–39 GHz and near 60 GHz being particularly prominent.

Regulation of the microwave spectrum is managed by international and national authorities, notably the ITU. Spectrum allocations designate bands for fixed, mobile, satellite, radar, and other services, and licensing requirements vary by country. Efficient management aims to minimize interference and enable reliable operation of microwave systems across applications.