Abstract: A phased array antenna having an array of antenna elements, an array of phase shifter sections, each one thereof being associated with a corresponding one of the antenna elements, and a cold-plate having a pair of surfaces, one of the surfaces having the array of phase shifter sections mounted, and thermally coupled, thereto and an opposite one of the pair of surfaces having thermally conductive posts projecting outwardly therefrom, each one of the posts being disposed behind a corresponding one of the plurality of mounted phase shifter sections. A heat sink plate is thermally coupled to distal ends of the posts. The cold-plate has a plurality of feeds passing therethrough. The phased array antenna includes a power/radio frequency energy distribution section mounted to said opposite one of the pair of cold plate surfaces for distributing power and radio frequency energy among the phase shifter sections mounted to the cold plate.