Abstract: To meet the miniaturization requirements of satellite system on solid state power amplifier (SSPA), a design approach on Ku-band 8W SSPA for satellite application was proposed. Firstly, all of the radio frequency functions are integrated in a single module, by using the integration design technique, to achieve the miniaturization characteristic of solid state power amplifier. Secondly, the design of heat dissipation was optimized, to achieve the high reliable characteristic of the product. Lastly, the anti-interference ability of the circuits was enhanced, by optimizing the design of DC power circuits, to ensure the stabilization of the SSPA. Using the above technologies, a Ku-band SSPA with output power of 8W, efficiency higher than 22%, and mass of only 770g was achieved. Compared to the traditional discrete devices technique, the volume of this product was reduced almost by half. The results of space environment test show that the Ku-band SSPA has high reliability and meets the requirements of aerospace applications. Actually, this product was already in orbit. The achieved Ku-band SSPA is very suitable for the use of “quick, intelligent, cheap” satellites in China, and has broad application prospect in the future.