Extra exam question E6E01

WhyGallium arsenide is useful for semiconductor devices operating at UHF and higher frequencies because of its higher electron mobility. Gallium arsenide's higher electron mobility compared to silicon lets charge carriers move through the material faster, which is exactly the property that lets GaAs devices continue delivering usable gain well up into UHF and microwave frequencies where silicon devices start to run out of speed, answer B. It doesn't have a lower junction voltage drop or lower transconductance in a way that explains this advantage, and higher noise figure is a drawback, not the reason GaAs is chosen.