Satellite communication plays a key role in supplying data in places that are difficult to access, such as airplanes or ships, as well as in the acquisition of Earth observation data. Here, too, the trend is towards higher volumes of data. This necessarily requires more bandwidth and therefore the use of higher frequency bands between 18 and 27 GHz. Up to now, this area has achieved fast data transmission by using travelling-wave tube amplifiers as power amplifiers. Solidstate power amplifiers (SSPAs) are an alternative offering lower supply voltage, reduced complexity of power supply components and a simpler mechanical design. Project ASTERIX will develop and evaluate SSPAs at 20 GHz and 26 GHz.