In order to realize more energy-efficient mobile radio base stations, the consortium partners of the joint project “EdgeLimit-Green ICT” are working on an innovative edge-cloud antenna system. Through a combination of efficient components and optimized, AI-supported control, the novel system will reduce energy losses during transmission in the millimeter wave range of 5G by at least 50%. In this context, Fraunhofer IAF is developing resource-efficient HEMTs based on the in-house MOCVD-produced power semiconductor AlScN, which allows significantly higher power density and higher gain. The industrial partners contribute know-how in transistor fabrication, IC processing, and real-world testing and evaluation.