Researchers at the Fraunhofer Institute for Applied Solid State Physics and the Karlsruhe Institute for Technology achieved 40 Gbps line-of-sight wireless transmission over a distance of 1 km using the 240 GHz spectrum band.
Under project "Millilink," the researchers developed electronic transmitters and receivers measuring 4 x 1.5 mm2 using semiconductor technology with high carrier mobility (HEMT), makes it possible to use the frequency between 200 and 280 GHz. The researchers said the atmosphere shows low attenuation in this frequency range, which enables broadband directional radio links.
The wireless transmission system was tested between two tall buildings in Karlsruhe.