Swedish researchers set new world record for wireless data transmission rates

A group of researchers from Chalmers University of Technology in Gothenburg, Sweden, and Ericsson is getting recognition for setting a new world record in wireless data transmission rates using a new type of microwave circuit.  

Herbert Zirath Chalmers


The transmission rate of 40 Gb/s set the record for an operating frequency of 140 GHz--more than 40 times faster than the ceiling for LTE Advanced of 1 Gbit/s, reports EE Times. The research was presented as part of a Breaking News panel at the 2014 IEEE Compound Semiconductor Integrated Circuits Symposium in La Jolla, Calif.

"We have designed circuits for signals at 140 Gigahertz, where we have a large bandwidth. In laboratory testing, we have achieved a transmission rate of 40 Gigabit data per second, which is twice as fast as the previous world record at a comparable frequency," said Herbert Zirath, who is a professor in high speed electronics at Chalmers. He is also employed by Ericsson Research on a part-time basis.

Some of the applications for quicker wireless data transmission that Zirath envisions include major cultural and sports events where high-resolution live films need to be transmitted to screens without any delay or long cables, and communication within and between the large computer rooms where digital files end up when placed in the cloud. Improved wireless transmission can also mean fewer cords in homes and at work spaces. The quick circuits are of interest to Ericsson as well in terms of transmitting signals to and from base stations and cellular towers. 

Backhaul and similar cell tower-to-tower applications are served today by transceivers in the 141.5 to 148 GHz band, but at half the speed of Zirath's invention, which he made at Chalmers in collaboration with researchers Sona Carpenter and Mingquan Bao, along with Simon He, who performed the data-transmission measurements, according to EE Times.

The chip size is 1.6 x 1.2 square millimeters. In order to double the speed of backhaul and similar wireless communications gear, the researchers used indium phosphide transceivers, which is one reason the inventors gave for succeeding when other attempts had failed.

"We have designed our circuits with very high bandwidth, greater than 30 GHz, in an advanced semiconductor process--250 nanometer DHBT [double heterojunction bipolar transistor] with four metal-layers offered by Teledyne Scientific of Thousand Oaks, Calif.," Zirath told EE Times.

The team has been working on the invention for more than a decade, starting with research on millimeter-wave transceivers about 12 years ago. The project is being funded by the Swedish Foundation for Strategic Research.

The next step involves moving from the laboratory to testing under real-life circumstances outdoors. Zirath said he believes it's only a matter of a couple of years before these circuits are used in practical applications.

For more:
- see this EE Times story
- see this post

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