German researchers claim record with 6 Gbit/s data rate at 71-76 GHz

Researchers from the University of Stuttgart and the Fraunhofer Institute for Applied Solid State Physics IAF are boasting a big achievement: Transmitting the contents of a conventional DVD in under 10 seconds by radio transmission, setting a new world record. The team used transmitters and receivers at 71-76 GHz E band.

They exceeded the state of the art by a factor of 10, with a data rate of 6 Gigabits per second over a distance of 37 kilometers, according to the Fraunhofer Institute. The team realized the record data transmission on a stretch between Cologne and the town of Wachtberg, Germany. The stations were located on the 45-story Uni-Center in Cologne and the site of the Space Observation Radar TIRA at the Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR in Wachtberg.

The collaborative project Advanced E Band Satellite Link Studies (ACCESS) was carried out by a research group headed by Professor Ingmar Kallfass from the Institute of Robust Power Semiconductor Systems (ILH) from the University of Stuttgart, the Institut für Hochfrequenztechnik und Elektronik (IHE) from KIT, Radiometer Physics GmbH, and the Fraunhofer Institute for Applied Solid State Physics IAF, according to a press release.

E band transmitters with parabolic antenna. (Credit: Photo Jörg Eisenbeis, KIT)

According to the release, the circuits are based on two transistor technologies developed and manufactured by the project partner Fraunhofer IAF. In the transmitter, the broadband signals are amplified to a comparatively high transmission power of up to 1 W with the help of power amplifiers on the basis of the compound semiconductor gallium-nitride. A highly directive parabolic antenna emits the signals. Built into the receiver are low-noise amplifiers on the basis of high-speed transistors using indium-gallium-arsenide-semiconductor layers with very high electron mobility. They ensure the detection of the weak signals at high distance.

Some applications for transmitting over distances like this are next-generation satellite communications that require an ever-increasing data offload from earth observation satellites down to earth. The researchers point out that 250 Internet connections can be supplied with 24 Mbit/s ADSL, and terrestrial radio transmissions in E-band are suitable as a cost-effective replacement for optical fiber or as ad-hoc networks in the case of crises and catastrophe, in addition to connecting base stations in the backhaul of mobile communication systems.

ACCESS was completed on April 30 and is being continued in a follow-up project called E Band Link Platform and Test for Satellite Communication (ELIPSE).

Along with the University of Stuttgart, the Fraunhofer Institute for Applied Solid State Physics IAF, and the Karlsruhe Institute of Technology (KIT), the industrial partner Radiometer Physics GmbH (A Rohde & Schwarz Company) is involved. The project was funded by the Federal Ministry for Economy and Energy (BMWi) on the basis of a resolution by the German Bundestag. Support was provided by Fraun­hofer FHR, the Uni-Center Cologne and the Südwest-Rundfunk (SWR), which granted access to their buildings.

For more:
- read this Gizmodo article
- read this press release

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