In what application is gallium arsenide used as a semiconductor material?

Gallium arsenide (GaAs) is a highly specialized semiconductor material known for its exceptional electron mobility, which is much higher than that of standard silicon. This property allows electrons to move through the material much faster, making it incredibly useful for very high-frequency applications. Because it can switch states rapidly and introduces very little thermal noise, gallium arsenide is predominantly used in microwave circuits and UHF/VHF low-noise amplifiers. It is typically not used for low-frequency RF, high-current rectifiers, or standard audio circuits because ordinary silicon components are cheaper, easier to manufacture, and perfectly adequate for those lower-frequency applications.