A transmit receive, T/R, daughter card assembly comprising: a printed circuit board, PCB, having first and second opposing surfaces (840a, 840b) and having a plurality unit cells (850a - 850p) with each unit cell having one or more electrical contacts on the first surface of said PCB and each unit cell having one or more electrical contacts on the second opposing surface of said PCB; a plurality of radio frequency, RF, circulators (842a - 842p) disposed on a first one of the first and second surfaces of said PCB, each of said circulators disposed within the boundaries of a respective one of said plurality of unit cells, and each of said circulators electrically coupled to at least some of the one or more electrical contacts within the respective unit cell; a thermally and electrically conductive ground plane disposed on the first one of the first and second surfaces of said PCB, said thermally and electrically conductive ground plane in thermal and electrical contact with said plurality of circulators; one or more RF integrated circuits disposed on a second, opposite one of the first and second surfaces of said PCB, each of said RF integrated circuits disposed within the boundaries of a respective one of said plurality of unit cells and each of said RF integrated circuits electrically coupled to at least some of the one or more electrical contacts on the second surface of said PCB within the unit cell in which the one or more RF integrated circuit is disposed; one or more thermal vias disposed through said PCB to provide thermal paths from the said thermally and electrically conductive layer disposed on the first one of the first and second surfaces of said PCB to the second opposing surface of said PCB; and one or more heat spreaders disposed on the second one of the first and second surfaces of said PCB which is opposite the surface on which the circulators are mounted, said one or more heat spreaders thermally coupled to said thermally and electrically conductive ground plane disposed on the first one of the first and second surfaces of said PCB through at least one of the one or more thermal vias. a printed circuit board, PCB, having first and second opposing surfaces (840a, 840b) and having a plurality unit cells (850a - 850p) with each unit cell having one or more electrical contacts on the first surface of said PCB and each unit cell having one or more electrical contacts on the second opposing surface of said PCB; a plurality of radio frequency, RF, circulators (842a - 842p) disposed on a first one of the first and second surfaces of said PCB, each of said circulators disposed within the boundaries of a respective one of said plurality of unit cells, and each of said circulators electrically coupled to at least some of the one or more electrical contacts within the respective unit cell; a thermally and electrically conductive ground plane disposed on the first one of the first and second surfaces of said PCB, said thermally and electrically conductive ground plane in thermal and electrical contact with said plurality of circulators; one or more RF integrated circuits disposed on a second, opposite one of the first and second surfaces of said PCB, each of said RF integrated circuits disposed within the boundaries of a respective one of said plurality of unit cells and each of said RF integrated circuits electrically coupled to at least some of the one or more electrical contacts on the second surface of said PCB within the unit cell in which the one or more RF integrated circuit is disposed; one or more thermal vias disposed through said PCB to provide thermal paths from the said thermally and electrically conductive layer disposed on the first one of the first and second surfaces of said PCB to the second opposing surface of said PCB; and one or more heat spreaders disposed on the second one of the first and second surfaces of said PCB which is opposite the surface on which the circulators are mounted, said one or more heat spreaders thermally coupled to said thermally and electrically conductive ground plane disposed on the first one of the first and second surfaces of said PCB through at least one of the one or more thermal vias.