Low-cost enabling technologies for T/R modules (TRMs) in phased array radars are proposed and analyzed in terms of technology, performance, and cost aspects. Phase and amplitude controlling integrated circuits (ICs) realized in a low-cost standard silicon process are demonstrated. The design of several ICs at the S-, C-, on X-band has shown that silicon germanium is a strong contender for gallium arsenide. This also applies to TRMs suited for military active phased array antenna (AESA) radars. The circuits presented in this paper are manufactured by austriamicrosystems in their 0.35 µm SiGe-BiCMOS process with an fT of around 70 GHz. A TRM packaging concept based on soldered surface-mount technology and organic substrates is also demonstrated. A cost analysis concludes that by using the proposed packaging concept and the SiGe core-chip technology, the TRM production cost can be potentially reduced by 70% compared to traditional ceramic hermetic packaging with core chip in GaAs technology.