Hans L. Hartnagel received his PhD in Engineering from the University of Sheffield. He is Professor of Electronic Engineering at the University of Newcastle upon Tyne, England, and the Professor of High Frequency Electronics at the Technical University of Darmstadt, Germany. He worked for a short period with the industrial company Telefunken in Ulm, West Germany, in research and development of microwave tubes. Later, he joined the National Institute of Applied Sciences in Rhône, France, and then the Department of Electronic and Electrical Engineering of the University of Sheffield as a member of staff. He is the author of several books and numerous scientific papers on microwave semiconductor devices, and their technology and circuits. He has held consulting positions with the Japanese MITI Laboratory ETL, the Avionics Laboratory in Ohio, and the David Sarnoff Research Center in Princeton, New Jersey, among others. His present research concerns III-V semiconductors, their devices (design, technology and characterization) and in particular MEMS, THz integration and mm-wave sensors. He has received external funding from the European Union, the German Government, the European Space Agency, Industry and the German Science Foundation DFG.