Gallium nitride (GaN) is a very hard, mechanically stable wide bandgap semiconductor. With higher breakdown strength, faster switching speed, higher thermal conductivity, and lower on-resistance, power devices based on GaN significantly outperform silicon-based devices.

The lower resistance and reduced gate charge enable faster power supply switching frequencies, resulting in higher power densities, improved efficiencies, and more compact and lightweight circuitry, key advantages for critical spaceborne missions.

Gallium nitride is also inherently radiation tolerant, making GaN-based devices a highly reliable option for space applications.

Radiation in Space

There are several types of radiation experienced by semiconductors in space. Devices in satellites orbiting Earth, as well as exploration spacecraft traveling to distant regions of our solar system, are exposed to continuous high-energy radiation bombardment.

Three of the primary types of radiation are:

• Gamma radiation
• Neutron radiation
• Heavy ion radiation

Unlike silicon, where special fabrication techniques and packaging are required to shield semiconductors from radiation effects, the intrinsic material properties and device structure of GaN make it relatively immune to radiation-induced damage in space environments.

Space Applications for GaN

Gallium nitride devices are already used in high volumes and have accumulated several years of flight heritage across a wide range of space applications. These applications benefit from the performance, efficiency, and rapid deployment enabled by GaN technology.

Key use cases include:

• Power supplies for satellites and mission equipment
• Light detection and ranging (LiDAR) systems for robotics, autonomous navigation, and rendezvous docking
• Motor drives for robotics and instrumentation
• Ion thrusters for satellite orientation, positioning, and interplanetary propulsion

Satellite Power Supply

Radiation-hardened GaN enables power supply designers to optimize systems for size, weight, efficiency, EMI, and power density.

The increased switching capability and reduced parasitics translate into lower losses, allowing engineers to increase switching frequency. This leads to:

• Reduced size and weight of magnetic components
• Reduced or eliminated heat sinking
• Lower copper losses

These benefits result in an overall reduction in system size and weight without sacrificing efficiency.

GaN-based power supplies operate at higher frequencies, deliver higher efficiencies, and achieve greater power densities for micro, LEO, and GEO satellites, as well as deep-space and outer space exploration missions.

Motor Drive for Satellite Reaction Wheels and Robotics

Reaction wheels are a critical component for satellites, enabling precise orientation and repositioning while in orbit. They operate by controlling the rotational speed of an electric motor connected to a flywheel.

The wide bandgap characteristics of radiation-hardened GaN power devices allow significantly higher switching frequencies with much lower switching losses. This enables the small size, light weight, and precision control required for miniaturized reaction wheels used in CubeSats.

These same advantages extend to ruggedized, high-precision brushless DC motors used in space robotics and automated instrumentation.

Autonomous Navigation and Docking

Light detection and ranging (LiDAR) systems provide the “eyes” for autonomous navigation and docking in rendezvous missions and robotic space operations.

The shorter the laser pulse, the higher the resolution of the generated images.

Radiation-hardened GaN devices deliver the fast switching speeds required for these short pulses, while also improving efficiency and reducing system size, making them ideal for advanced LiDAR systems in space.

Ion Thrusters

An ion thruster is a form of electric propulsion used for in-mission spacecraft maneuvering, including satellite orientation, positioning, and interplanetary propulsion of low-mass robotic vehicles.

Radiation-hardened GaN enables smaller, lighter, and more efficient power supplies for these systems, increasing power delivery and overall propulsion efficiency.