Mission critical systems demand the absolute maximum reliability possible. This high level of reliability is critical to military microwave amplifier systems. This paper shows how the modular design of solid state power amplifiers can provide dramatically higher levels of system reliability than traveling wave tube amplifiers. The HPA-20000 series from Paradise Datacom is a modular amplifier system that can provide up to 1.1 kW output power in C-Band (5.850-6.425 GHz) or 600W in X-Band (7.9 – 8.4 GHz).