This article describes the characterization of Monolithic Microwave Integrated Circuit (MMIC) amplifier die before and after packaging. Die level characterization is performed using RF probe station. MMIC die is packaged in a connectorized aluminium housing for further characterization. Characterization of MMIC die using probe station at microwave frequencies involves utmost handling as both RF & DC measurements are carried out simultaneously. The measurement is performed by incorporation of die capacitors, and proper connections so as to have repeatable performance. Also, calibration aspects to be taken care. Further packaging of the die introduces parasitics mostly at launching and output side for which proper characterization to be carried out. In this article, MMIC Die at C-band is characterized both at die & package level. The result indicates package introduces losses. The packaging effects are simulated in standard software tools. Effects of packaging & assembly techniques on RF performance of the connectorized amplifier module are minimized. Interconnection wire-bond length between die and alumina substrates optimized for minimum loss. Gaps between the MMIC die and substrates & carrier plate and housing are reduced to avoid discontinuities in ground plane. The bare die is biased for 4 V drain voltage to draw 45 mA current. The characterized bare die using RF probe station has a gain of 17 dB, comparable to simulated data sheet specifications. Connectorized module after packaging has a gain of 16 dB. Comparison of the simulated and measured packaging effects with bare die is performed and analysis carried out. The packaging technique implemented in this article are to find out a working die for intended aerospace application. The connectorized amplifier module can be used for aerospace applications after screening tests.