What is considered millimeter wave?

Abstract: Multiple-input multiple-output (MIMO) systems are well suited for millimeter-wave (mmWave) wireless communications where large antenna arrays can be integrated in small form factors due to tiny wavelengths, thereby providing high array gains while supporting spatial multiplexing, beamforming, or antenna …

Millimeter waves are used for military fire-control radar, airport security scanners, short range wireless networks, and scientific research . In a major new application of millimeter waves, certain frequency ranges near the bottom of the band are being used in the newest generation of cell phone networks, 5G networks.

Millimeter waves are electromagnetic (radio) waves typically defined to lie within the frequency range of 30–300 GHz . The microwave band is just below the millimeter-wave band and is typically defined to cover the 3–30-GHz range.