May 2020

24 POWER GAN www.infineon.com/gan Issue 2 2020 Power Electronics Europe www.power-mag.com GaN for Power-Hungry 5G Base Stations There is a significant change currently underway in the world of mobile telecommunications: the rollout of the fifth generation of cellular network technology, otherwise known as 5G. Consumers are only just beginning to experience the benefits of 5G technology, which will not only enable ultrafast download speeds to rival fixed-line broadband, but will in future also support a much higher density of mobile and connected IoT devices within cellular network areas. But that 5G will consume more power than 4G is an inescapable reality. GaN in SMD packages are a perfect match for the particular requirements of 5G network infrastructure. Francesco Di Domenico, Principal Application Engineering, Infineon Technologies, Neubiberg, Germany There is a significant change currently underway in the world of mobile telecommunications: the rollout of the fifth generation of cellular network technology, otherwise known as 5G. Consumers are only just beginning to experience the benefits of 5G technology, which will not only enable ultrafast download speeds to rival fixed-line broadband, but will in future also support a much higher density of mobile and connected IoT devices within cellular network areas. Exciting as this development may be for the consumer, behind the scenes the industry’s move to 5G has been challenging, costly and controversial. Issues such as the allocation of radio frequency spectrum licenses [1], ill-informed myths stoking panic about the health risks of 5G for users [2], and the fallout from cybersecurity fears between international trade rivals[ 3] have dogged the migration process throughout. Although 5G will no doubt be a profitable venture for cellular carriers and network operators, it will require an exponential upfront investment to upgrade, improve and replace the existing cellular network infrastructure. However, it is not just the upfront cost of the network overhaul that is likely keeping network operators awake at night, but the ongoing operational expenditure as well. The fact that 5G will consume more power than 4G is an inescapable reality; in fact, power consumption is predicted to rise by almost 70 percent as a consequence (Figure 1). For example, where a 4G base station might require around 7 kW of power, a 5G base station will need over 11 kW - and some stations carrying multiple channels could even consume up to 20 kW. More of everything is needed Even though the technology behind 5G networks are generally more efficient than 4G, the increased capacity of each cell will result in an overall increase in power consumption. The reason for this is the use of Massive MIMO (Multiple-Input, Multiple- Output) antennas over a single radio channel to improve signal quality. In comparison with 4G base stations, which typically use 4T4R (4 transmitters, 4 receivers), 5G base stations employ 64T64R. It is thus no mystery to see why the demand for power is so much higher. Some 5G network providers struggling with the mechanics of delivering it are even debating the possibility of limiting the number of transceivers at base stations to 32T32R in order to save power, even though this would effectively throttle the capacity of the network. To compound the issue of increased power demands at existing base stations, the other challenge is the need for more base stations than ever before. This is partly because the radio wavelengths particular to 5G technology have a more limited range, meaning that a greater concentration of base stations will be needed to provide given areas with effective coverage. The cost of building these new base stations and installing the power grid that will support them will be enormous. Finally, there is the problem of power supplies; the industry standard of 3 kW 48 VDC will be woefully inadequate, even if the total amount of power required only doubles. Power density will therefore need to be increased significantly to deliver the same amount of power using a comparable amount of space. Moving to the edge 5G networks will see the network map undergo significant change as increased processing power migrates closer to the edge where data collection actually takes place Figure 1: The power consumption of a typical 5G telecom site (Source: Huawei Technologies)