Energy efficient millimeter wave transmitters

Important results from the project

The overall objective has been to evaluate the potential of gallium nitride (GaN) for wireless communication 5G and point-to-point link transmitters. The project has shown that commercial mm-wave GaN technologies have many remaining challenges in terms of reliability, accessibility and performance. Thus, additional fundamental material and component research is needed to enable the full potential of GaN in commercial mm-wave applications.

Expected long term effects

The project has resulted in a deep understanding of tradeoffs between linearity and efficiency in GaN power amplifiers at RF and mm-wave. New circuit solutions have been developed and patented by Ericsson as part of the project. The project has also demonstrated how GaN can improved phase noise in mm wave oscillators. The project has resulted in closer collaboration between Chalmers and Ericsson within the area of mm-wave transmitters. This is of major strategic importance for both parties, considering that energy efficiency is a key parameter in the realization of 5G base stations

Approach and implementation

Ericsson and Chalmers have worked closely together throughout the project, e.g. through construction in the same GaN technologies and with joint thesis projects. The cooperation has also been supported by Ericsson having SSF Mobility Grants and Associate Professors who worked part-time at Chalmers. Since the core research focused on fundamental understanding rather than specific results, we have been able to adapt to delays and problems with GaN processes and instead demonstrated the concepts with GaN at lower frequency. This gives the project results a long-term value.