Phased array antenna systems, which use sets of two or more antennas, offer improved performance over single antennas and are well-known for their usefulness in radar and aerospace applications. Communication system design software supports the design and analysis of phased arrays, as well as their implementation in a system of antenna elements, power divider/combiners, phase shifters, and other typical components. This article examines how software can be used to simulate both small and large phased arrays in typical configurations.