M.E.C.’s X390-647 (4×9-Element) is an X-band, Series-Fed patch array antenna possessing low side lobe levels and narrow beamwidth. This lightweight, low-profile antenna provides a directional beam with high efficiency and is suitable for a variety of modern satellite communications and multipurpose radar applications. This antenna can be mounted on both flat and conformal surfaces due to its low-profile and planar form factor. By varying the size of appropriate patches in subarrays, one can compensate for curvature effects in conformal mounting.