Design considerations for aperture-coupled microstrip patch phased arrays taking into account mutual coupling effects

High resolution imaging radar systems for spaceborne remote sensing applications require large phased array antennas with a wide bandwidth. Aperture-coupled microstrip patch elements are well suited for this application. The paper discusses the design and performance of a 96×128 element broadband aperture-coupled microstrip patch phased array antenna. A finite as well as an infinite array approach are used to account for mutual coupling effects on the active reflection coefficients as well as on the active radiation patterns. The influence of the subarray size on the scan performance is addressed. Finally the measured performance of an 8×8 element phased array antenna breadboard is presented