This research project deals with the magnetron, an electron beam tube, in which a structurized electron beam interacts with an electro-magnetic resonant structure. Thus electric power can be generated at frequencies in the submillimeter-wave range. This range is of high actual interest, because it offers a number of technical and scientific applications. Our investigations are aiming to develop a completely new physical model of the magnetron with the potential to realize a quantitative design following well-defined criteria for the first time. Thus the road will be paved leading to a powerful but still handy high-frequency generator for the so-called terahertz (THz) frequency range. The new model shall be able to establish optimization guidelines for the operational and geometrical parameters and detect completely new modes of operation. These investigations will be illustrated by several experimental prototypes, which shall be produced by the world-wide leading magnetron laboratory in Kharkov, Ukraine.