This course will provide a working knowledge of the key parameters of modern phased array antenna systems. Phased arrays are a key component in radars, wireless and satellite communications, remote sensing and imaging systems, and in scientific instruments such as radio telescopes. Students will learn to critically evaluate the performance of phased array antenna systems with emphasis on factors that are important for high-performance radar and communication systems such as scanning, sidelobe levels, gain, bandwidth, sensitivity, linearity, etc.