Kassiopeia Project Aims to Create Spaceborne Devices with an Emphasis on Power Electronics

May 09, 2021 by Alessandro Mascellino

Ferdinand-Braun-Institut (FBH), SweGaN AB, and the University of Bristol are partnering to design and manufacture new spaceborne devices.

In particular, the institutions will work on high-performance Ka-band GaN MMICs (monolithic microwave integrated circuits) to be integrated into beam steering antennas for satellite communications and radar applications.

The collaboration is part of the Kassiopeia project, funded by the European Space Agency.


Kassiopeia European Project Aims to Create Spaceborne Devices Fig1 Fixed
The institutions part of the Kassiopea project. Logos courtesy of the respective institutions.

A European Collaboration

The Kassiopea project was first launched last month to build an entirely independent European supply chain, from silicon carbide (SiC) substrates and gallium nitride (GaN) epitaxy to GaN device processing and power amplifiers.

The consortium is led by FBH in Berlin, and aims to achieve its goal by developing and demonstrating highly efficient GaN and aluminum nitride (AlN) devices using novel epitaxy,

processing, and circuit concepts.

In addition, FBH will contribute to the project with its industry-compatible Ka-band MMIC technology on 100 mm GaN-on-SiC wafers.

The solution is not only reportedly capable of reducing dynamic losses (gate lagging) to values up to two times less than competing institutional and industrial technologies but can also substantially improve device reliability.

SweGaN, on the other hand, will support the Kassiopea project with its buffer-free solution for GaN-on-SiC epiwafers (QuanFINE) and in-house developed semi-insulating SiC substrates.

"We are excited to participate in this ESA-aligned project together with FBH and the University of Bristol,” said Jr-Tai Chen, CTO of SweGaN. 

According to the executive, conventional GaN-on-SiC materials for Ka band applications still lack maturity, enabling significant possibilities for innovation and improvement. 

“SweGaN will introduce its revolutionary epitaxial manufacturing process to address the challenge,” Chen added.

Finally, the University of Bristol’s Center for Device Thermography and Reliability (CDTR) will enable the consortium to research direct thermal measurements on active GaN transistors by using micro-Raman thermography and advanced device characterizations and modeling.


Developing Spaceborn Devices

The ultra-wide bandgap semiconductors being researched by the Kassiopea team possess exceptional physical and electrical properties.

These devices are usually made of aluminum nitride, boron nitride or diamond, and can consequently operate at higher temperatures, voltages, and frequencies than silicon.


A scanning electron microscope image of gallium nitride MMICs. Image used courtesy of FBH.
A scanning electron microscope image of gallium nitride MMICs. Image used courtesy of FBH.

This makes them significantly more powerful and energy-efficient than traditional Si-based power electronics. 

Moreover, ultra-wide bandgap materials also enable power substations' footprint to be reduced up to a hundredfold, thus saving space and increasing the reliability of the grid and its integration of renewable energy sources.

In fact, while traditional electricity grids are built to deliver power in only one direction (from power plants to consumers) renewable energy sources require more flexibility.

In other words, grids powered by wind and solar power can provide energy in ideal conditions, but their cells and batteries also need to be recharged when there is not enough wind or sun. 

The Kassiopeia project’s new research will now enable the development of a ‘smart grid’ capable of meeting these multidirectional demands.

The ensuing technology will provide substantial advantages in performance and reliability, which are particularly relevant for spaceborne devices and applications.

The Kassiopeia project has received funding under the ESA ARTES Advanced Technology Programme named “European Ka-band high power solid-state technology for active antennas”.