How GaN Is Improving Space Exploration
By John Oncea, Editor
As the space industry expands, GaN will play an increasingly crucial role in enabling more ambitious and efficient space missions.
Semiconductors are made from a variety of materials including silicon, germanium, gallium arsenide, silicon carbide, indium phosphide, cadmium sulfide, and the subject of this article, gallium nitride (GaN).
Of the eight materials listed above, germanium was the first material used for semiconductors. Silicon has been used extensively since it came on the scene in the 1950s and GaN is the second most common material in use today. Unlike silicon and germanium, GaN is a compound, not an element, and is made by combining gallium, with its three valence electrons, with arsenic, which has five valence electrons.
“Eight valence electrons make gallium-arsenide devices respond quickly to electric signals, making the compound well suited for amplifying the high-frequency signals seen in television satellites,” writes IEEE. “GaN has some limitations, however: the compound is more difficult to manufacture en masse than silicon, and the chemicals used in its production are quite toxic.”
Some experts believe silicon is approaching the limits of Moore’s Law as demands for faster, smaller integrated circuits are being made. Should these experts prove right, GaN – along with antimonide-based and bismuthide-based semiconductors, graphene, and pyrite – is being viewed as the material of choice for semiconductors for the foreseeable future.
An added benefit of turning to GaN s is that this type of semiconductor is generally considered the best for us in space due to its high radiation resistance, ability to operate at high temperatures and voltages, and excellent power capacity.
This is important because, according to Vyrian, “The space semiconductor market is growing rapidly due to the increasing demand for satellites and other equipment used in space exploration. The global space semiconductor market is expected to reach a value of $4.9 billion by 2027, growth (that) can be attributed to the increasing demand for satellite communications and the development of sophisticated payloads.
“The growing launch of satellites also has had a positive impact on the space semiconductor industry as it is driving demand for various electronic components, chipsets, and processors. Moreover, the miniaturization of electronics and the rising number of IoT devices in aerospace applications are expected to boost the demand for space semiconductor chipsets.
EE Times Europe adds that, according to Yole Intelligence’s Taha Ayari and Aymen Ghorbel, “New Space – the low Earth orbit (LEO) mission segment, with a typical satellite lifespan of three to five years and lower reliability requirements – has become a focal point for GaN adoption. As a result, power GaN devices are being adopted for various satellite systems, including DC/DC converters, point-of-load systems, motor drives, and ion thrusters.”
Why GaN Is The Semiconductor Of Choice
GaN has emerged as a promising technology for space applications, particularly in two key areas: power GaN high-electron-mobility transistors (HEMTs) and RF GaN power amplifiers (PAs). Compared to traditional silicon MOSFETs, GaN HEMTs offer superior radiation tolerance and hardness, along with improved efficiency and more compact form factors at the system level.
GaN devices also present a cost advantage over their silicon counterparts. While Si MOSFETs for space applications typically require dedicated, low-volume production lines with specialized designs, GaN devices can leverage shared production facilities with high-volume terrestrial applications like automotive, resulting in lower manufacturing costs.
From an RF perspective, GaN high-power amplifiers exhibit exceptional characteristics for satellite communication uplink transmitters. These devices deliver high output power, superior power-added efficiency, and excellent ruggedness and durability. The combination of performance benefits and cost-effectiveness makes GaN an attractive choice for power applications in space systems.
“As of 2023, satellite communication systems mainly use GaAs power amplifiers due to their low cost,” Ayari and Ghorbel told EE Times Europe. “On the other hand, GaN-based power amplifiers could offer attractive performance/cost ratios as well as superior thermal management compared with GaAs solutions. Over the 2020–2023 period, GaN has gained market share since its performance meets the new requirements going to higher frequencies. GaN technology can afford higher data throughput, larger bandwidth to cover more spectrum with better efficiency, and smaller antenna size.”
While GaN shows great promise, there are still some challenges including the establishment of reliable European supply chains for space-grade GaN, according to the European Space Agency. Other challenges are qualifying GaN processes for space applications and developing more advanced GaN technologies for future space needs.
Despite these challenges, GaN is poised to play an increasingly important role in enabling more capable, efficient, and reliable space systems in the coming years, powering critical systems like communication, data storage, and power management.
The semiconductor industry is expected to continue innovating to meet the evolving needs of space technology. Ongoing developments in chip design, materials science, and integration techniques promise to further enhance space exploration capabilities.