Phased array antennas were first used in military radar systems to scan the radar beam quickly across the sky to detect planes and missiles. These systems are becoming popular for a variety of applications and new active electronically scanned arrays (AESAs) are being used for radar systems in satellites and unmanned aerial vehicles. As these systems are deployed in new and novel ways, size and performance requirements are becoming critical and are being addressed through innovative architectures and system capabilities. These are made possible through improvements in microwave and signal processing technologies such as gallium nitride (GaN) power amplifiers (PAs), new monolithic microwave integrated circuit (MMIC) / extreme MMIC  devices, heterogeneous More-than-Moore integration, cost reductions for transmit/receive (TX/RX) modules, new millimeter-wave (mmWave) silicon ICs, and electro-optic integration .1 This white paper examines the challenges associated with designing next-generation AESAs and the ways in which the Cadence® AWR Design Environment® platform enables engineers to meet the evolving requirements of unique architectures and system capabilities.