The realization of powerful and efficient Active Antenna System for 5G BTS operating in millimeter frequency bands is requiring a new generation of Front-End modules. Various die technologies and amplifier architectures are currently considered to address the integration of high power millimeter Front-End in an active antenna system. The main challenges are: (i) the package size which has to be compatible with antenna mesh (ii) the thermal dissipation and electrical connections which have to be placed in order to ease antenna design (iii) the linearity and the robustness to load variation which are parameters to take into account in the choice of power architecture (iv) The level of output power, the consumption, the noise, switching time, which require high performance die technology. Recent solutions based on GaN and GaAs adopted for the realization of a 5G 24–30GHz, high power front-end module will be presented. Powerful and efficient active antenna combining several tens of those modules is currently under development.