Abstract:The characters of the miniaturization,light weight and available extension make the three-dimensional Transmit Receive(T/R) module become one of the important development trends in the T/R module technology field. In this paper, a Ku band T/R module with 3-D structure is studied. First the vertical structure, the circuit layout and passive model are studied; then a miniaturized T/R module is designed, which has excellent electrical performance(Pout≥24.5 dBm,Gr≥25 dB,NF≤3.5 dB). The module is miniaturized by adopting three methods, including designing a three-layer structure, the use of high density Low Temperature Co-fired Ceramic(LTCC)and Ball Grid Array(BGA), and making a multi-chip. The dimension of T/R module is 9.5 mm×9.5 mm×3.8 mm.