5G technology is set to bring an unprecedented level of high speeds, greater bandwidth and increased network capacity as compared to current 3G/4G technologies. While a host of MNOs (Mobile Network Operators) are now working on the deployment of 5G networks, the rollout in many countries, like USA, has been hindered by gaps in available technology that could operate at the high frequencies required by 5G.
But now, an electrical engineer at the University of Houston is creating a roadmap towards that 5G future, using a $1.7 million grant to design and build a system capable of supporting 5G infrastructure. Harish Krishnamoorthy, Assistant Professor of Electrical and Computer Engineering, is working on the Department of Defense-funded project with New Edge Signal Solutions, a Massachusetts company which builds high-speed broadband radio frequency systems.
Krishnamoorthy, whose lab focuses on power electronics, said successful adoption of 5G networks will require adapting software to support the demands. But first, there is need of hardware that is fast enough and capable of supporting 5G.
That’s where he comes in, charged with developing a higher power 5G envelope tracking power supply that can operate at a bandwidth of 100 megahertz (MHz) or more; current state-of-the-art envelope bandwidth in commercial applications is about 20 MHz for a peak power of greater than 65 watts, according to Krishnamoorthy. The higher bandwidth allows 5G systems to offer better speed, resolution and clarity.
Envelope tracking is a type of power supply modulation technique that continuously adjusts the converter voltage used by the radio frequency power amplifier in order to keep it running at peak efficiency. Boosting both frequency and power at the same time is technically challenging, in part because of the excess heat produced. The continuous adjustment via envelop tracking can significantly reduce the amount of waste heat produced by the system, despite the higher power output.
4G systems, by comparison, typically operate on established frequencies at lower peak power and at a lower bandwidth. One hundred MHz is just a starting point for 5G, Krishnamoorthy said. Even getting to that point is hard with current technology. There is a need to advance power electronics to support that. The goal over the five-year life of the project is to exceed 100 MHz at close to 200 watts peak power.
According to Krishnamoorthy the work will proceed in steps, through the use of better device technologies, paralleling power converters and including a smart error correction technique, without which it would be unable to achieve the efficiency as well as linearity targets of the project.
