Satellite Communications (SATCOM) Practice Test

Phased array antennas provide rapid, electronic beam steering without moving parts, which is ideal for satellite links that need to cover large or moving areas with high data rates. The systems that prominently use onboard phased-array technology to form and steer multiple beams are those like Starlink, MILSTAR, and DSCS/WGS. Starlink satellites, for example, rely on phased arrays to create thousands of beams that can be directed where needed as the constellation moves overhead. MILSTAR and DSCS/WGS were designed for global, flexible, high-capacity links and use onboard phased-array antennas to rapidly reconfigure coverage and maintain robust communications. GPS satellites and weather satellites typically do not rely on onboard phased arrays as their primary spaceborne antenna solution. GPS uses fixed-pattern, broad-beam radiators tailored for consistent global coverage, while weather satellites generally employ traditional dish or other conventional antennas for their downlink. Scientific satellites vary widely in their antenna choices, but phased arrays are not the defining characteristic for most of them.