This paper presents a 1.5 - 54 GHz high dynamic range low noise amplifier (LNA) and mixer combination MMIC, which is the core component of a monostatic multiple input, multiple output (MIMO) imaging radar receiver system. The circuit is implemented in a mathbf0.13 mumathbfm SiGe BiCMOS process from IHP and occupies a core area of only 0.6 mm ² , Controlled feedback, common-base mixer inputs, patterned transmission line grounds and a folded differential distributed amplifier topology were employed to optimize the performance. Ultra-wideband operation from 1.5 to 54 GHz, low noise of mathbfNF -mathbfdsb =mathbf4.8 dB , high linearity of mathbfP -mathbfin ,mathbf1dB =-mathbf1 dBm , controlled conversion gain in the range of 0 - 12 dB and a +20 dBm survivability were measured at a DC power consumption of 194 mW. With respect to these core design parameters, the proposed LNA and mixer combination outperforms the state of the art of its class.