The MIDAS project will redress the technology imbalance between the EU and the US in a most significant area of European technology non-dependence, affecting the scientific and commercial exploitation of the sub-millimetre region of the electro-magnetic spectrum. Within MIDAS, critical Schottky varactor diodes and the simulation tools for fabricating and designing state-of-the-art sub-millimetre wave components and sources will be developed. Using these, a demonstrator terahertz source will be fabricated, with the aim of generating levels of RF power previously unavailable within Europe. A small team of complementary expertise has been chosen to undertake the programme, combining world class researchers in the respective fields of circuit simulation, design and fabrication, with the leading SME in Europe supplying terahertz components to the space and commercial arenas. European amplifier technology, combined with optimised Schottky varactors fabricated on diamond substrates, will demonstrate a novel, generic, terahertz source technology, enabling planned sub-millimetre wave space science and Earth observation instrumentation to use wholly European technology. The ability for Europe to exploit the terahertz spectrum, which is recognised to be of key scientific and commercial importance, will be significantly enhanced.