From 2020, the new 5G mobile communication standard is expected to make both consumers and companies happy. But, unfortunately, the technology is still missing. An EU project based on gallium nitride will now put an end to this drawback.
At the end of the 1950s, the analog A network of the old Federal Republic of Germany was the largest public mobile communications network in the world. Back then, a switchboard operator connected tens of thousands of subscribers. This was followed by the B network and, then, in 1985, the C network, which was the first partially digital mobile communications network. It was not until the D network (2G, GSM) arrived in 1992 that mobile data transfer was possible. 3G (UMTS) and, especially, the current 4G (LTE) increased data rates significantly. The operators, however, always focused on cell phone users.
But with the fifth generation (5G), automobiles, devices, and production machines will also be able to transfer data. To achieve the required bit rates of 10 Gbit/s the frequency bands have to work in the millimeter wavelength range (>24 GHz), where they provide ten times higher bandwidth than the frequency bands that were used previously (< 3 GHz). Also important is signal delay (latency), which 5G will shorten by a factor of 40. It will then be just one millisecond – in other words, almost real time, which is indispensable for many applications in industry, medicine, and autonomous driving.
GaN for fast networks
However, the current mobile communication and antenna technology in the base stations is not designed for this. In the future, it will have to fulfill three criteria: Higher power output, lower costs, and lower energy consumption. To achieve this, in the EU project “5G GaN2”, 17 partners from science and industry are developing amplifier circuits based on the gallium nitride (GaN) technology of the Fraunhofer IAF. Components made from the wide bandgap III-V semiconductor can withstand higher voltages and temperatures than their silicon counterparts and are also much more energy efficient. Large volumes of the raw materials gallium and nitrogen are available and the development of blue and white LEDs has made production of GaN a lot cheaper. In 2014, the material was even involved in the Nobel Prize for Physics. Japanese scientists Akasaki, Amano, and Nakamura received the award for developing blue LEDs based on GaN 22 years earlier.
In other words, GaN is especially suitable for powerful high frequency amplifiers in the base stations of future mobile communication networks. But even people who are connected with the world with a smartphone via LTE may already have received a data packet from a GaN high frequency amplifier in the low gigahertz range. But this will have to be faster in the future. This is why the EU project “5G GaN2” is developing demonstrators for the 28 GHz, 38 GHz, and 80 GHz ranges.