Abstract: The traditional ultra-wideband T/ R module is a two-dimensional brick structure, the volume and weight are not suitable for the miniaturized, low profile and conformal phased array antenna. In this paper, the four-channel radio frequency (RF) chips are highly integrated on the silicon-based substrate based on the silicon stack system in package (SIP) technology, and the multilayer substrate is thick gold pressed to achieve multi-layer stacked 3D packaging. The 3D stacked four-channel ultra-wideband T/R module is realized by adopting multi-function integration technology of chip and vertical interconnection technology of ultrawideband RF signal. The bandwidth of the T/R module is 6 GHz~ 18 GHz, single-channel transmitting power is better than 23 dBm, the receiving gain is better than 20 dB, 6 bit digital control attenuation and 6 bit digital control phase shift are realized, the size is only 13.0 mm×13.0 mm×3.4 mm. This technology can realize SIP packaging of multi-channel ultra wideband T/R module, which is beneficial for engineering applications.