An extreme wideband arbitrary waveform generator (AWG) is presented which is used for creating extreme wideband THz radio signals. The block diagram of a corresponding THz transmitter which is based on infrared heterodyning is shown in Fig. 1. The output of the photodiodes is directly coupled to the transmitting antenna (A. Stöhr, A. Czylwik, T. Kaiser, K. Solbach: Tera50 - A 10 - 1000 GHz wireless measurement system with 50 GHz bandwidth. European Microwave Week 2013, Nuremberg, Nov. 7, 2013).