ABSTRACT
Electronically scanned arrays (ESA) provide the capability of commandable, agile, high-gain beams, which is advantageous for applications such as radar, weather surveillance, and imaging. Scanning the beam with an ESAs can be performed on the order of microseconds as opposed to milliseconds for a reflector. When designing ESAs, there are basic fundamentals that need to be understood for a successful design that is., grating lobes, beamwidth, instantaneous bandwidth. Additionally, a fundamental understanding of the application of ESAs is necessary that is., pattern optimization, subarrays, digital beamforming. After these foundations are set, then an understanding of practical aspects of ESAs, such as reliability, should provide a well-rounded understanding of designing ESAs. Electronic scan can be categorized as phase steering or time delay steering. For phase steering, each element has a phase shifter and applies the appropriate phase as a function of frequency and scan angle. For ESAs that employ both phase and time delay, both forms of delay must be adjusted.
