An antenna system including: a metal base plate; an antenna element arranged on and extending away from the front side of the base plate; a circuit board including a ground plane, adjacent to, and in thermal contact with the base plate; a plurality of electrical components on the circuit board including a power amplifier and an I/O connector; a metal support plate separated from, parallel to, and facing the base plate, with the circuit board located between the base and support plates; a plurality of thermally conductive standoffs thermally connecting the base plate to the support plate; and a master board including an I/O connector mating with the I/O connector on the circuit board and electrically connecting the circuit board to the master board, the master board located between the circuit board and the support plate and including signal paths for routing signals to the circuit board.