Book excerpt: This book focuses on the multi-beam phased array antenna as a satellite ground station. As there are already many excellent books on phased array antennas in the literature, this book focuses mainly on some engineering practices and fills the gap between principles and practices, such as array excitation error impact analysis and calibration methods, array geometry design for hemispherical coverage, multiple beam resource management, etc. This book is particularly suitable for readers interested in satellite constellation design or satellite ground station design. This book also benefits researchers and engineers in the fields of phased array antennas, aerospace engineering, telecommunications, etc.